Durability

耐久性
  • 文章类型: Journal Article
    背景:在经导管瓣膜介入治疗的时代,生物外科二尖瓣置换术(SMVR)仍然是一种重要的治疗选择。我们介绍了使用当代低调二尖瓣猪瓣膜进行SMVR的Medicare受益人的10年临床结果。
    方法:这是一项使用Medicare按服务收费索赔数据的单臂观察性研究。使用Epic™二尖瓣接受SMVR的去识别患者(Abbott,明尼苏达,美国)在美国2008年1月1日至2019年12月31日之间由ICD-9/10程序代码选择,然后链接到制造商设备跟踪数据库。全因死亡率,心力衰竭(HF)再次住院,使用KaplanMeier方法在10年时评估了二尖瓣再介入治疗(手术或经导管瓣膜).
    结果:在研究期间接受SMVR的75,739名Medicare受益人中,14,015例植入了Epic™二尖瓣,其中76.5%(10,720)有潜在的HF。平均年龄74±8岁。术前无HF患者的10年生存率为40.4%(95%CI37.4%-43.4%),而HF患者为25.4%(95%CI23.8%-27.0%)(p<0.001)。HF再住院的10年自由度为51.3%(95%CI49.4%-53.1%)。10年时,二尖瓣再介入的自由度为91.4%(95%CI89.7%-92.7%)。
    结论:这项针对接受Epic™二尖瓣的Medicare受益人的全国现实研究表明,在植入后10年,无90%的全因瓣膜再干预和无50%的HF再住院。发现患有二尖瓣疾病并接受SMVR的人群的长期生存和HF再住院受到潜在HF的影响。
    BACKGROUND: Bioprosthetic surgical mitral valve replacement (SMVR) remains an important treatment option in the era of transcatheter valve interventions. We present 10-year clinical outcomes of Medicare beneficiaries undergoing SMVR with a contemporary low-profile mitral porcine valve.
    METHODS: This is a single-arm observational study using Medicare fee-for-service claims data. De-identified patients undergoing SMVR with the Epic™ Mitral valve (Abbott, Minnesota, USA) in the United States between 1/1/2008-12/31/2019 were selected by ICD-9/10 procedure codes and then linked to a manufacturer device tracking database. All-cause mortality, heart failure (HF) re-hospitalization, and mitral valve reintervention (surgical or transcatheter valve-in-valve) were evaluated at 10-years using the Kaplan Meier method.
    RESULTS: Among 75,739 Medicare beneficiaries undergoing SMVR during the study period, 14,015 were implanted with the Epic™ Mitral valve, of which 76.5% (10,720) had underlying HF. Mean age was 74±8 years. Survival at 10-years in patients without preoperative HF was 40.4% (95% CI 37.4%-43.4%) compared to 25.4% (95% CI 23.8%-27.0%) for patients with HF (p < 0.001). The 10-year freedom from HF rehospitalization was 51.3% (95% CI 49.4%-53.1%). Freedom from mitral valve reintervention was 91.4% (95% CI 89.7%-92.7%) at 10 years.
    CONCLUSIONS: This real-world nationwide study of Medicare beneficiaries receiving the Epic™ Mitral valve demonstrates >90% freedom from all-cause valve reintervention and >50% freedom from HF rehospitalization at 10-years post-implant. Long-term survival and HF rehospitalization in this population with mitral valve disease undergoing SMVR was found to be impacted by underlying HF.
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  • 文章类型: Journal Article
    比较耐力运动员中等强度训练的一个长和两个短时间和强度匹配的训练之间的急性生理反应和感知的训练压力。
    十四名男性耐力运动员(VO2max:69.2±4.2mL·min-1·kg-1)进行了一次6×10分钟的间隔训练(SINGLE)和两次3×10分钟的间隔训练,并在两天内进行了6.5小时的中等强度训练恢复(DOUBLE),在实验室跑步时,使用平衡交叉试验。将两个训练日分为第一部分/会话(间隔阶段1-3)和第二部分/会话(间隔阶段4-6)。呼吸变量,心率(HR),血乳酸浓度(BLa),并在会话期间收集感知劳累(RPE)评级,而仰卧心率(HR)则在疗程结束后的60分钟恢复期内进行评估.在第二天的早晨评估了感知的训练压力(1-10)的度量。
    HR,BLA,与第一部分相比,第二部分的RPE增加(168±7vs.173±7bpm,2.60±0.75vs.3.01±0.81mmol·L-1,13.4±1.0vs.14.8±1.1点,分别,所有p<0.05)。与第一届DOUBLE相比,第二届HR和Bla下降(171±9vs.166±9bpm和2.72±0.96vs.分别为2.14±0.65mmol·L-1,两者p<0.05)。SinGLE在疗程后的恢复期显示出更高的仰卧HR(65.4±2.5vs.60.7±2.5bpmp<0.05),会话RPE(sRPE,7.0±1.0vs.6.0±1.3点,p=.001)和sRPE训练负荷(929±112vs.743±98,p<0.001)与DOUBLE相比。第二天早上,与DOUBLE(7.0±2.5vs.8.0±1.0点,p=.049和6.0±2.5vs.7.0±2.5点,分别为p=.002)。
    与两次短时间和强度匹配的训练相比,一次长期的中等强度训练与生理反应的持续时间依赖性“漂移”有关,从而暗示了更高的整体训练刺激。同时,两个较短会议的成本较低,表明这种组织可以在这种强度下允许更多的累积时间。总的来说,这些发现可以作为更好地理解组织中等强度训练的利弊的起点,因为长时间训练与较短的训练进行得更频繁(例如,作为“双门槛训练”)在耐力运动员中。
    UNASSIGNED: To compare acute physiological responses and perceived training stress between one long and two short time- and intensity-matched sessions of moderate-intensity training in endurance athletes.
    UNASSIGNED: Fourteen male endurance athletes (VO2max: 69.2 ± 4.2 mL·min-1·kg-1) performed one 6 × 10-min interval session (SINGLE) and two 3 × 10-min interval sessions interspersed with 6.5 h recovery (DOUBLE) of moderate-intensity training on two separate days, while running in the laboratory, using a counterbalanced cross-over trial. The two training days were separated into a first part/session (interval stage 1-3) and second part/session (interval stage 4-6). Respiratory variables, heart rate (HR), blood lactate concentrations (BLa), and rating of perceived exertion (RPE) were collected during sessions, whereas supine heart rate (HR) was assessed in a 60-min recovery period following sessions. Measures of perceived training stress (1-10) were assessed in the morning of the subsequent day.
    UNASSIGNED: HR, Bla, and RPE increased in the second compared to first part of SINGLE (168 ± 7 vs. 173 ± 7 bpm, 2.60 ± 0.75 vs. 3.01 ± 0.81 mmol·L-1, and 13.4 ± 1.0 vs. 14.8 ± 1.1-point, respectively, all p < 0.05). HR and Bla decreased in the second compared to first session of DOUBLE (171 ± 9 vs. 166 ± 9 bpm and 2.72 ± 0.96 vs. 2.14 ± 0.65 mmol·L-1, respectively, both p < 0.05). SINGLE revealed higher supine HR in the recovery period following sessions (65.4 ± 2.5 vs. 60.7 ± 2.5 bpm p < 0.05), session RPE (sRPE, 7.0 ± 1.0 vs. 6.0 ± 1.3-point, p = .001) and sRPE training load (929 ± 112 vs. 743 ± 98, p < 0.001) compared to DOUBLE. In the subsequent morning, increased levels of perceived fatigue and muscle soreness were observed following SINGLE compared to DOUBLE (7.0 ± 2.5 vs. 8.0 ± 1.0-point, p = .049 and 6.0 ± 2.5 vs. 7.0 ± 2.5-point, p = .002, respectively).
    UNASSIGNED: One long moderate-intensity training session was associated with a duration-dependent \"drift\" in physiological responses compared to two short time- and intensity-matched sessions, thereby suggesting a higher overall training stimulus. Simultaneously, the lower cost of the two shorter sessions indicates that such organization could allow more accumulated time at this intensity. Overall, these findings serve as a starting point to better understand the pros and cons of organizing moderate-intensity training as one long versus shorter sessions performed more frequently (e.g., as \"double threshold training\") in endurance athletes.
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  • 文章类型: Journal Article
    用于民用的拉挤纤维增强聚合物复合材料,电源,和海上/海洋应用使用填料作为树脂增量剂和过程效率。虽然填料的主要用途是以增量剂和加工助剂的形式,填料的适当选择可以提高机械性能,耐用性,和多功能性。这在结构和高电压应用中是特别感兴趣的,其中特定填料的先前使用的水平太低而不能提供这些增强。这项研究调查了使用三种不同粒径的蒙脱土有机粘土填料作为常规CaCO3填料的替代品,目的是提高机械性能和湿热耐久性。该研究调查了水分吸收和动力学,并揭示了两阶段过程很好地描述了吸收,该过程包含了扩散主导的初始阶段和代表松弛和劣化的第二较慢阶段。与使用CaCO3填料相比,有机粘土颗粒的掺入大大降低了吸收水平,同时还增强了阶段I,扩散,主导稳定性,在相同的20%负载水平(以树脂的重量计)下,与CaCO3填料相比,使用1.5mm有机粘土填料的峰值吸收显示多达41.5%的减少。使用张力表征机械性能,挠曲,和短梁剪切试验。有机粘土填料在每种填料中都显示出显着的改善,尽管由于粒度的差异。总的来说,4.8mm有机粘土填料基E-玻璃/乙烯基酯复合体系显示出在去离子水中浸泡四种不同温度后的最佳性能,在研究的最高温度(70°C)下,在去离子水中浸入一年后,这是唯一一个在所有特性上的劣化小于50%的人。填料不仅增强了抗吸收能力,而且增加了路径中的弯曲度,从而降低摄取的整体效果。观察结果表明,使用带有插层的剥离有机粘土颗粒,以前使用的量非常低,并且已知在增强热稳定性方面是有益的,阻燃性,和降低可燃性,提供增强的机械特性,减少水分吸收,和增加的湿热耐久性,当使用在颗粒负载水平可比的常规填料,这表明这些新颖的系统可以被考虑用于关键的结构应用。
    Pultruded fiber reinforced polymer composites used in civil, power, and offshore/marine applications use fillers as resin extenders and for process efficiency. Although the primary use of fillers is in the form of an extender and processing aid, the appropriate selection of filler can result in enhancing mechanical performance characteristics, durability, and multifunctionality. This is of special interest in structural and high voltage applications where the previous use of specific fillers has been at levels that are too low to provide these enhancements. This study investigates the use of montmorillonite organoclay fillers of three different particle sizes as substitutes for conventional CaCO3 fillers with the intent of enhancing mechanical performance and hygrothermal durability. The study investigates moisture uptake and kinetics and reveals that uptake is well described by a two-stage process that incorporates both a diffusion dominated initial phase and a second slower phase representing relaxation and deterioration. The incorporation of the organoclay particles substantially decreases uptake levels in comparison to the use of CaCO3 fillers while also enhancing stage I, diffusion, dominated stability, with the use of the 1.5 mm organoclay fillers showing as much as a 41.5% reduction in peak uptake as compared to the CaCO3 fillers at the same 20% loading level (by weight of resin). The mechanical performance was characterized using tension, flexure, and short beam shear tests. The organoclay fillers showed a significant improvement in each, albeit with differences due to particle size. Overall, the best performance after exposure to four different temperatures of immersion in deionized water was shown by the 4.8 mm organoclay filler-based E-glass/vinylester composite system, which was the only one to have less than a 50% deterioration over all characteristics after immersion for a year in deionized water at the highest temperature investigated (70 °C). The fillers not only enhance resistance to uptake but also increase tortuosity in the path, thereby decreasing the overall effect of uptake. The observations demonstrate that the use of the exfoliated organoclay particles with intercalation, which have been previously used in very low amounts, and which are known to be beneficial in relation to enhanced thermal stability, flame retardancy, and decreased flammability, provide enhanced mechanical characteristics, decreased moisture uptake, and increased hygrothermal durability when used at particle loading levels comparable to those of conventional fillers, suggesting that these novel systems could be considered for critical structural applications.
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  • 文章类型: Journal Article
    防止混凝土结构钢筋的腐蚀对于保持结构的完整性和承载能力至关重要,因为它直接影响混凝土结构的安全性和使用寿命。通过防止钢筋腐蚀,结构的耐久性和抗震性能可以显著提高。这项研究调查了腐蚀和非腐蚀工程水泥基复合材料(ECC)-玻璃纤维增强聚合物(GFRP)螺旋约束钢筋混凝土(RC)柱的滞后行为。采用实验方法和有限元分析,这项研究探索了关键的地震参数,如裂缝模式,故障模式,滞后反应,承载能力,延展性,刚度退化,和能量耗散。结果表明,ECC-GFRP螺旋约束RC柱,与传统的RC柱相比,显示降低的腐蚀速率,较小的裂缝宽度,更少的腐蚀产物,表明优越的裂纹控制和耐腐蚀性。滞后测试表明,ECC-GFRP柱,在20%的目标腐蚀率下,表现出增强的承载能力,延展性,和能量耗散,表明改进的耐久性和抗震恢复力。参数和敏感性分析证实了有限元模型的准确性,并强调了混凝土抗压强度对承载能力的重要影响。研究结果表明,ECC-GFRP螺旋约束RC柱在沿海和地震易发地区提供了有希望的应用,增强耐腐蚀性和机械性能,从而潜在地降低模板成本,提高施工质量和效率。
    Preventing corrosion in the steel reinforcement of concrete structures is crucial for maintaining structural integrity and load-bearing capacity as it directly impacts the safety and lifespan of concrete structures. By preventing rebar corrosion, the durability and seismic performance of the structures can be significantly enhanced. This study investigates the hysteresis behavior of both corroded and non-corroded engineered cementitious composite (ECC)-glass-fiber-reinforced polymer (GFRP) spiral-confined reinforced-concrete (RC) columns. Employing experimental methods and finite element analysis, this research explores key seismic parameters such as crack patterns, failure modes, hysteretic responses, load-bearing capacities, ductility, stiffness degradation, and energy dissipation. The results demonstrate that ECC-GFRP spiral-confined RC columns, compared to traditional RC columns, show reduced corrosion rates, smaller crack widths, and fewer corrosion products, indicating superior crack control and corrosion resistance. Hysteresis tests revealed that ECC-GFRP columns, at a 20% target corrosion rate, exhibit an enhanced load-bearing capacity, ductility, and energy dissipation, suggesting improved durability and seismic resilience. Parametric and sensitivity analyses confirm the finite element model\'s accuracy and highlight the significant influence of concrete compressive strength on load-bearing capacity. The findings suggest that ECC-GFRP spiral-confined RC columns offer promising applications in coastal and seismic-prone regions, enhancing corrosion resistance and mechanical properties, thus potentially reducing formwork costs and improving construction quality and efficiency.
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  • 文章类型: Journal Article
    对于聚乳酸(PLA)和PLA/淀粉复合材料在玩具等技术部件中的应用,了解它们在热液环境中的相关应用条件下的降解行为至关重要。为此,由PLA和天然马铃薯淀粉制成的复合材料使用双螺杆挤出机生产,然后加工成试样,然后在不同的温度(23、50、70、90°C)和湿度水平(10、50、75、90%)下进行各种为期一周的老化过程。随后进行机械表征(拉伸试验)和使用凝胶渗透色谱(GPC)的降解鉴定,热重分析(TGA),傅里叶变换红外光谱(FTIR),和核磁共振波谱(NMR)。随着温度和湿度的增加,解放军有明显的退化,可以通过添加50wt来减少或减缓。%淀粉,由于结晶度增加。水解是PLA和PLA/淀粉复合材料的主要降解机理,尤其是高于玻璃化转变温度,与热氧化降解也起从属作用。水解降解和热氧化降解均导致机械性能如拉伸强度的降低。
    For the application of poly(lactic acid) (PLA) and PLA/starch composites in technical components such as toys, it is essential to know their degradation behavior under relevant application conditions in a hydrothermal environment. For this purpose, composites made from PLA and native potato starch were produced using twin-screw extruders and then processed into test specimens, which were then subjected to various one-week ageing processes with varying temperatures (23, 50, 70, 90 °C) and humidity levels (10, 50, 75, 90%). This was followed by mechanical characterization (tensile test) and identification of degradation using Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance spectroscopy (NMR). With increasing temperature and humidity, there was a clear degradation of the PLA, which could be reduced or slowed down by adding 50 wt.% starch, due to increased crystallinity. Hydrolysis was identified as the main degradation mechanism for PLA and PLA/starch composites, especially above the glass transition temperature, with thermo-oxidative degradation also playing a subordinate role. Both hydrolytic degradation and thermo-oxidative degradation led to a reduction in mechanical properties such as tensile strength.
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  • 文章类型: Journal Article
    本文简要介绍了微胶囊自修复技术及其在混凝土结构中的潜在用途。因为混凝土是现成的,价格合理,它在全球建筑行业广泛使用,尽管它容易形成裂缝。混凝土建筑物的寿命和安全性受到其使用过程中出现的裂缝和其他劣化的存在的极大影响。通过将愈合材料封装在微胶囊内,这表明水泥基材料开裂时破裂,微胶囊在实现自我修复和增加结构的耐久性和强度方面表现出希望。本文首先解释了微胶囊自愈科学背后的基本思想,然后探讨了制备微胶囊的不同方法。它还研究了添加微胶囊如何影响混凝土建筑的基本特征。还提供了微胶囊的效率和自修复机制的概述。
    文章阐述了微胶囊自修复法在混凝土中的优势。讨论了不同微胶囊的制备方法和内在性质。讨论了水泥基材料中不同的自愈合测量技术。该研究检查了各种自我修复方法的定性方面。研究添加微胶囊如何影响胶凝材料的性能。
    This article provides a brief description of microcapsule self-healing technique and its potential use in concrete structures. Because concrete is readily available and reasonably priced, it is widely utilised in the building industry globally, despite its susceptibility to the formation of cracks. The longevity and security of concrete buildings are greatly impacted by the existence of cracks and other deterioration occurring during the course of their use. Through the encapsulation of healing material inside microcapsules, which shows rupture upon cracking in cement-based materials, the microcapsule exhibits promise in accomplishing self-healing and increasing durability and strength in the structures. The article first explains the basic ideas behind the science of microcapsule self-healing and then looks at different ways to prepare microcapsules. It also looks into how adding microcapsules affects the basic characteristics of the concrete building. A summary of the efficiency and self-healing mechanisms of microcapsules is also provided.
    The article explains the advantages of the microcapsule self-healing method in concrete.Preparation method and intrinsic properties of different microcapsules are discussed.Different self-healing measurement techniques in cement-based materials are discussed.The study examines the qualitative aspects of various self-healing methods.Looks into how adding microcapsules affects the properties of cementitious materials.
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  • 文章类型: Journal Article
    在自愈混凝土的研发过程中,据观察,控制混凝土自愈效果的主要因素有三个:第一,细菌具有修复能力和强大的生命力;其次,载体的承载能力和与混凝土的匹配度;三是细菌浓度。本文重点研究了剑麻纤维对枯草芽孢杆菌自修复混凝土的力学性能,PVA,以膨胀珍珠岩为载体。为了更好地研究载体引起的自愈合混凝土的力学性能,试验采用C30混凝土的设计参数,进行抗压试验,抗弯性,冻融循环,分析了不同载体对自愈混凝土力学性能的影响,并获得最好的载体。将三组菌液的浓度梯度设定为2od,2.5od,和3od,分别,用于比较,以避免细菌浓度的影响。比较了细菌溶液浓度对试样力学性能的影响,并对载体的作用进行了分析。实验结果表明,以PVA为载体的2.5d菌液浓度试样的力学性能达到峰值。随着细菌溶液浓度的增加,试样的综合力学性能先升高后降低。含PVA的试样的抗压缩性高于含剑麻纤维和膨胀珍珠岩的试样。同时,PVA载体试样的抗冻性和耐腐蚀性也高于剑麻纤维和膨胀珍珠岩载体试样。
    In the process of research and development of self-healing concrete, it is observed that there are three main factors controlling the self-healing effect of concrete: first, the bacteria with repair ability and strong vitality; Second, the carrying capacity of the carrier and the matching degree with concrete; The third is the concentration of bacteria. This paper focuses on the mechanical properties of Bacillus subtilis self-healing concrete with sisal fiber, PVA, and expanded perlite as the carrier. To better study the mechanical properties of self-healing concrete caused by the carrier, the experiment adopts the design parameters of C30 concrete and conducts experiments on compressive resistance, flexural resistance, freeze-thaw cycle, and sulfate corrosion resistance to analyze the influence of different carriers on the mechanical properties of self-healing concrete, and obtains the best carrier. The concentration gradients of three groups of bacterial solution were set as 2od, 2.5od, and 3od, respectively, for comparison to avoid the influence of bacterial concentration. It compared the impact of bacterial solution concentrations on the specimen\'s mechanical properties, and the effect of carriers was also analyzed. The experimental results show that the mechanical properties of the specimen using 2.5od bacterial liquid concentration with PVA as the carrier have peaked. With the increase in bacterial solution concentration, the specimens\' comprehensive mechanical properties increased first and then decreased. The compression resistance of the specimen with PVA is higher than that of the specimen with sisal fiber and expanded perlite. At the same time, the frost resistance and corrosion resistance of the PVA carrier specimen is also higher than that of the specimen with sisal fiber and expanded perlite carrier.
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  • 文章类型: Journal Article
    疫苗接种诱导的免疫反应的纵向变化在青少年中仍未得到充分表征。我们提供长期安全,免疫原性,和COVID-19在2剂量mRNA-1273.100μg初级系列后的发病率,在未接种疫苗的青少年中单剂量mRNA-127350μg后的免疫原性。
    TeenCOVE(NCT04649151)第1部分将青少年(12-17岁)随机分为2剂量mRNA-1273.100μg(n=2490)或安慰剂(n=1243),间隔28天。随后,安慰剂组(n=91)可接受开放标记mRNA-1273.主要目标包括12个月内的预设不良事件;次要目标是12个月内的COVID-19发生率以及针对SARS-CoV-2(祖先/变体)的中和和结合抗体(nAbs/bAbs)(研究期:2020年12月至2022年1月)。在第2部分中,未接种疫苗的青少年(n=52)接受了多达2剂mRNA-127350μg;中期分析包括SARS-CoV-2基线阳性参与者注射后第28天(D28)nAbs(先前感染的血清学/病毒学证据)。
    在SARS-CoV-2基线阴性的青少年中(N=369),mRNA-1273在D28(1868[1759-1985])时与基线相比诱导了稳健的nAb反应(几何平均浓度[GMC]=11;95%CI,11-12),注射后6个月(625[583-670])和12个月(550[490-618])2.对α/β/δ/γ变体观察到类似的bAb反应;在SARS-CoV-2基线阳性青少年中,nAb/bAb反应相似。2剂量mRNA-1273.100-μg主要系列通常耐受性良好;一例非严重,中度,可能的急性心肌炎在症状发作后8天内消退。在SARS-CoV-2基线阳性的青少年中,单剂量的mRNA-127350μg诱导的D28nAbGMC比在年轻人中的2剂量的mRNA-1273.100μg高(几何平均比=4.322[3.274-5.707])。
    mRNA-1273的总体风险-收益特征在青少年中仍然有利,具有针对SARS-CoV-2(祖先/变体)的持续12个月的免疫反应。在未接种疫苗的青少年中单次注射50μgmRNA-1273引起针对SARS-CoV-2的强烈免疫反应。
    该项目全部或部分由卫生与公共服务部的联邦资金资助,美国;战略准备和反应管理局,美国;生物医学高级研究与发展局,美国,根据合同编号75A50120C00034。本报告中的发现和结论是作者的发现和结论,不一定代表卫生与公共服务部或其组成部分的观点。
    UNASSIGNED: Longitudinal changes in vaccination-induced immune response remain inadequately characterized in adolescents. We present long-term safety, immunogenicity, and COVID-19 incidence following a 2-dose mRNA-1273 100-μg primary series, and immunogenicity following a single dose of mRNA-1273 50 μg in vaccine-naïve adolescents.
    UNASSIGNED: TeenCOVE (NCT04649151) Part 1 randomized adolescents (12-17 years) to 2-dose mRNA-1273 100 μg (n = 2490) or placebo (n = 1243) 28 days apart. Subsequently, placebo recipients (n = 91) could receive open-label mRNA-1273. Primary objectives included prespecified adverse events through 12 months; secondary objectives were COVID-19 incidence and neutralizing and spike-binding antibodies (nAbs/bAbs) against SARS-CoV-2 (ancestral/variants) through 12 months (study period: December 2020-January 2022). In Part 2, vaccine-naïve adolescents (n = 52) received up to 2 doses of mRNA-1273 50 μg; interim analysis included Day 28 (D28) nAbs post-injection 1 in SARS-CoV-2-baseline-positive participants (serologic/virologic evidence of prior infection).
    UNASSIGNED: In SARS-CoV-2-baseline-negative adolescents (N = 369), mRNA-1273 induced robust nAb responses versus baseline (geometric mean concentration [GMC] = 11; 95% CI, 11-12) at D28 (1868 [1759-1985]), 6 months (625 [583-670]) and 12 months (550 [490-618]) post-injection 2. Similar bAb responses were observed to alpha/beta/delta/gamma variants; nAb/bAb responses were similar in SARS-CoV-2-baseline-positive adolescents. The 2-dose mRNA-1273 100-μg primary series was generally well-tolerated; one case of nonserious, moderate, probable acute myocarditis resolved by 8 days from symptom onset. A single dose of mRNA-1273 50 μg in SARS-CoV-2-baseline-positive adolescents induced higher D28 nAb GMCs against ancestral SARS-CoV-2 than 2-dose mRNA-1273 100 μg in young adults (geometric mean ratio = 4.322 [3.274-5.707]).
    UNASSIGNED: The overall risk-benefit profile of mRNA-1273 remains favorable in adolescents, with durable 12-month immune responses against SARS-CoV-2 (ancestral/variants). A single mRNA-1273 50-μg injection in vaccine-naïve adolescents elicited robust immune responses against SARS-CoV-2.
    UNASSIGNED: This project has been funded in whole or in part with federal funds by the Department of Health and Human Services, United States; Administration for Strategic Preparedness and Response, United States; Biomedical Advanced Research and Development Authority, United States, under Contract No. 75A50120C00034. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Department of Health and Human Services or its components.
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  • 文章类型: Journal Article
    目的:经导管主动脉瓣置换术(TAVR)确定了严重症状性主动脉瓣狭窄患者治疗的范式转变,但缺乏长期耐久性的数据。我们试图在12年的随访中评估CoreValve猪心包自膨胀生物假体的临床和血液动力学结果。
    方法:在2007年至2011年期间,在8个意大利高容量中心对882名无法手术或高危患者进行了CoreValve生物假体治疗。终点是12年全因死亡率和心血管死亡率,和累积入射函数(CIF)的严重结构阀门退化(SVD),生物瓣膜功能障碍(BVD),生物瓣膜衰竭(BVF),和严重的血流动力学瓣膜恶化(HVD)。应用VARC-3定义。
    结果:基线特征包括平均年龄83±6岁,和NYHAIII级或IV级76.3%的患者。TAVR后12年的精算死亡风险为95.5%(CI93.5%-97.1%)。心血管死亡的实际风险,12年时非心源性死亡风险的加权率为23.9%(21.0%-26.8%).BVD的12年实际风险为7.0%(5.3%-8.9%),SVD为3.6%(2.5%-5.2%),BVF为3.12%(2.02%-4.57%),重度HVD为1.7%(0.9%-2.9%)。手术后平均经主动脉梯度显着降低(52±15mmHgvs9±5mmHg,p<0.001),并保持稳定长达12年(12±4mmHg,P=0.08vs.放电)。
    结论:第一代CoreValve生物假体在12年的随访中表现出令人放心的临床和血流动力学性能。
    OBJECTIVE: Transcatheter aortic valve replacement (TAVR) determined a paradigm shift in the treatment of patients with severe symptomatic aortic stenosis but data on very long-term durability are lacking. We sought to evaluate the clinical and hemodynamic outcomes of the CoreValve porcine pericardial self-expanding bioprosthesis at 12-year follow-up.
    METHODS: 882 inoperable or high-risk patients were treated with the CoreValve bioprosthesis in 8 Italian high-volume centers between 2007 and 2011. The endpoints were 12-year all-cause and cardiovascular mortality, and Cumulative Incidence Functions (CIFs) for severe Structural Valve Deterioration (SVD), Bioprosthetic Valve Dysfunction (BVD), Bioprosthetic Valve Failure (BVF), and severe Hemodynamic Valve Deterioration (HVD). VARC-3 definitions were applied.
    RESULTS: Baseline characteristics included a mean age of 83 ± 6 years, and NYHA class III or IV in 76.3 % of patients. The actuarial risk of death at 12 years after TAVR was 95.5 % (CI 93.5 %- 97.1 %). The actual risk of cardiovascular death, weighted against the risk of non-cardiac death at 12 years was 23.9 % (21.0 %-26.8 %). The 12-year actual risk of BVD was 7.0 % (5.3 %-8.9 %), of SVD was 3.6 % (2.5 %-5.2 %), of BVF was 3.12 % (2.02 %-4.57 %), and of severe HVD was 1.7 % (0.9 %-2.9 %). Mean transaortic gradient significantly decreased after the procedure (52 ± 15 mmHg vs 9 ± 5 mmHg, p < 0.001), and remained stable up to 12 years (12 ± 4 mmHg, P = 0.08 vs. discharge).
    CONCLUSIONS: The first-generation CoreValve bioprosthesis showed reassuring clinical and hemodynamic performance at 12-year follow-up.
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  • 文章类型: Journal Article
    尽管在硫酸方面取得了巨大的进步,它仍然是极具挑战性的属性组合的优良的机械性能,所需的耐用性,高消防安全。因此,无催化剂,闭环可回收酯交换玻璃化聚合物(TPN1.50)具有优异的机械性能,耐用性,通过在环氧树脂(EP)中引入合理设计的叔胺/含磷反应性低聚物(TPN)来开发阻燃性。由于TPN和EP之间的强共价相互作用及其线性低聚物结构,制备的TPN1.50具有86.2MPa的拉伸强度和6.8MJm-3的韧性,优于以前的玻璃化者。含1.50重量%磷的TPN1.50显示出理想的阻燃性,包括35.2%的极限氧指数和垂直燃烧(UL-94)V-0分类。TPN1.50具有出色的耐用性,可以在1MHCl或NaOH溶液中保持其结构完整性100天。这是因为叔胺锚定在交联网络中,并被刚性的含P基团封闭,从而有效地抑制酯交换。由于其良好的化学回收率,TPN1.50可用作制造可回收碳纤维增强聚合物复合材料的有前途的树脂。这项工作提供了一种有前途的集成方法,用于创建坚固耐用的防火玻璃,以促进高性能聚合物复合材料的可持续发展。
    Despite great advances in vitrimer, it remains highly challenging to achieve a property portfolio of excellent mechanical properties, desired durability, and high fire safety. Thus, a catalyst-free, closed-loop recyclable transesterification vitrimer (TPN1.50) with superior mechanical properties, durability, and fire retardancy is developed by introducing a rationally designed tertiary amine/phosphorus-containing reactive oligomer (TPN) into epoxy resin (EP). Because of strong covalent interactions between TPN and EP and its linear oligomer structure, as-prepared TPN1.50 achieves a tensile strength of 86.2 MPa and a toughness of 6.8 MJ m-3, superior to previous vitrimer counterparts. TPN1.50 containing 1.50 wt% phosphorus shows desirable fire retardancy, including a limiting oxygen index of 35.2% and a vertical burning (UL-94) V-0 classification. TPN1.50 features great durability and can maintain its structure integrity in 1 M HCl or NaOH solution for 100 days. This is because the tertiary amines are anchored within the cross-linked network and blocked by rigid P-containing groups, thus effectively suppressing the transesterification. Owing to its good chemical recovery, TPN1.50 can be used as a promising resin for creating recyclable carbon fiber-reinforced polymer composites. This work offers a promising integrated method for creating robust durable fire-safe vitrimers which facilitate the sustainable development of high-performance polymer composites.
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