Continuous-flow

连续流
  • 文章类型: Journal Article
    蒽醌染料是仅次于偶氮染料的第二重要类型的染料。特别是,1-氨基蒽醌已广泛用于制备多种蒽醌染料。本研究采用连续流方法通过高温氨解1-硝基蒽醌,安全有效地合成1-氨基蒽醌。各种条件(反应温度,停留时间,氨与1-硝基蒽醌的摩尔比(M比),和水含量)进行了研究,以探索氨解反应行为的细节。在响应面法中使用Box-Behnken设计优化了连续流氨解的操作条件,在213°C和4.3min时,M比为4.5,可获得约88%的1-氨基蒽醌产率。通过进行4小时的过程稳定性测试来评估开发过程的可靠性。在连续流模式下研究了制备1-氨基蒽醌的动力学行为,以指导反应器设计并对氨解过程有更深入的了解。
    Anthraquinone dyes are the second most important type of dyes after azo dyes. In particular, 1-aminoanthraquinone has been extensively utilized in the preparation of diverse anthraquinone dyes. This study employed a continuous-flow method to synthesize 1-aminoanthraquinone safely and efficiently through the ammonolysis of 1-nitroanthraquinone at high temperatures. Various conditions (reaction temperature, residence time, molar ratio of ammonia to 1-nitroanthraquinone (M-ratio), and water content) were investigated to explore the details of the ammonolysis reaction behavior. Operation conditions for the continuous-flow ammonolysis were optimized using Box-Behnken design in the response surface methodology, and ~88% yield of 1-aminoanthraquinone could be achieved with an M-ratio of 4.5 at 213 °C and 4.3 min. The developed process\'s reliability was evaluated by performing a 4 h process stability test. The kinetic behavior for the preparation of 1-aminoanthraquinone was investigated under continuous-flow mode to guide the reactor design and to gain a deeper understanding of the ammonolysis process.
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  • 文章类型: Journal Article
    在这里,我们报道了活性芳烃的生态友好型光化学氧化Csp2-H硫氰酸化和硒氰化。该反应在紫罗兰LED照射下在K2S2O8的存在下进行,K2S2O8迅速氧化KSCN和KSeCN,最终产生芳硫基/硒氰酸酯。利用这种良性的,原子经济协议,区域选择性地获得所需的硫属化物产物,与分离的产量范围从非常好的优秀。虽然,机理研究表明,很难区分自由基与SEAr反应机理之间的光诱导形成的•SCN,对于前者,或NCSSCN,对于后者,芳香杂环。抑制实验以及观察到的反应性和区域选择性,会同意后者。设计的合成方法可以成功地适用于分段流动状态的连续流系统,采用有机相作为产品储集器。使用此设置,后者的优点可以通过减少反应时间和提高产物收率来证明。同样,将反应扩大到克级,通过流动设置产生了有利的结果,它将光流化学安装为常规反应程序中包含的强大工具,这对制药行业有很大的意义。
    Herein, we report an eco-friendly photochemical oxidative Csp2-H thiocyanation and selenocyanation of activated arenes. The reaction proceeds under Violet LED irradiation in the presence of K2S2O8, which quickly oxidizes KSCN and KSeCN, finally producing arylthio/selenocyanates. Using this benign, atom-economic protocol, the desired chalcogenide products were obtained regioselectively, with isolated yields that range from very good to excellent. Although, mechanistic study indicates that it is difficult to distinguish between a radical to a SEAr reaction mechanism between the photo-induced formed •SCN, for the former, or NCSSCN, for the latter, to the aromatic heterocycles. The inhibition experiment together with the observed reactivity and regioselectivity, would be in agreement with the latter. The synthetic methodology designed could be successfully adapted to continuous-flow systems in a segmented-flow regime, employing the organic phase as the product reservoir. Using this setup, the advantage of the latter can be demonstrated by reducing the reaction time and improving the product yields. Similarly, the scaling up of the reaction to gram scale resulted in favorable outcomes by the flow setup, which installs the photo-flow chemistry as a powerful tool to be included into routine reaction procedures, which have great relevance for the pharmaceutical industry.
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  • 文章类型: Journal Article
    心室辅助装置(VAD)在治疗成年人群终末期心力衰竭方面的成功导致了VAD设计的工业创新,专注于小型化和减少并发症。这些创新的副产品是新一代设备可以在儿科人群中具有临床应用。在过去的十年里,VAD在儿科人群中的使用急剧增加,新一代连续流(CF)设备已经开始取代旧的,脉动流(PF)装置,以前是儿科人群中心室辅助的唯一选择。然而,尽管儿科人群中VAD植入物的增加,患者人数仍然很低,在儿科VAD中心之间共享数据的需求对于全球VAD计划的持续增长变得更加重要。建立儿科VAD登记处,例如机械循环支持儿科登记处(PediMACS),欧洲机械循环支持患者注册(EUROMACS)和先进的心脏治疗改善结果网络(ACTION)已经能够从全球VAD中心收集汇总数据,并为临床医生和项目提供了宝贵的资源,随着越来越多的小儿心力衰竭患者被认为是VAD治疗的候选人。
    The success of ventricular assist devices (VADs) in the treatment of end-stage heart failure in the adult population has led to industrial innovation in VAD design, focusing on miniaturization and the reduction of complications. A byproduct of these innovations was that newer generation devices could have clinical applications in the pediatric population. Over the last decade, VAD usage in the pediatric population has increased dramatically, and the newer generation continuous flow (CF) devices have begun to supplant the older, pulsatile flow (PF) devices, formerly the sole option for ventricular assist in the pediatric population. However, despite the increase in VAD implants in the pediatric population, patient numbers remain low, and the need to share data between pediatric VAD centers has become that much more important for the continued growth of VAD programs worldwide. The creation of pediatric VAD registries, such as the Pediatric Registry for Mechanical Circulatory Support (PediMACS), the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) and the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) has enabled the collection of aggregate data from VAD centers worldwide, and provides a valuable resource for clinicians and programs, as more and more pediatric heart failure patients are considered candidates for VAD therapy.
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  • 文章类型: Journal Article
    据报道,严重的右心室衰竭(RVF)使左心室辅助装置(LVAD)放置复杂化,发生率为10-30%。虽然主要用于左心室衰竭,心室辅助装置(VAD)已用于双心室设置中,以对抗LVAD植入后的右心室衰竭(RVF)。随着连续流LVAD(CF-LVAD)取代其脉动前辈的出现,向CF-双心室辅助装置(CF-BiVAD)的转变,与以往的搏动型BiVAD相比,有望改善预后.我们的目标是回顾文献并确定CF-BiVAD接受者的结果。
    进行了系统评价以确定CF-BiVAD的结果。收集术前人口统计和设备配置数据。评估的主要结果是短期生存率,长期生存,持续时间的支持,和移植的生存。评估的次要结局包括重症监护病房(ICU)和住院时间(ICU-LOS和HLOS,分别),泵血栓形成,泵交换。在适当情况下报告中位数和四分位数范围。一个主要的限制是不同出版物的队列可能重叠,这可能导致了一些选择偏差。
    筛选了1,282个,评估了12种出版物。样本量从4到93个CF-BiVAD接受者,随访6~24个月。平均年龄为34至52岁。45%的CF-BiVAD有右心房(RA-)流入插管,其余为右心室(RV)。30天生存率的中位数为90%(IQR82-97.8%),12个月生存率的中位数为58.5%(IQR47.5-62%)。据报道,泵血栓形成(主要是右VAD)的中位数为31%(IQR14-36%),虽然泵交换只有9%(IQR1.5-12.5%)。
    LVAD植入后的RVF是一种高发病率和死亡率的并发症。当前没有可用的标签上连续流RVAD。因此,用于右心室支持以对抗泵血栓形成的LVAD的修改产生了多种技术.BiVAD接受者主要是移植候选人,等待名单上的泵血栓形成和传动系统感染的并发症是非常重要的。该研究表明需要标签上的CF-BiVAD。
    UNASSIGNED: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients.
    UNASSIGNED: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias.
    UNASSIGNED: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%).
    UNASSIGNED: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.
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  • 文章类型: Journal Article
    开发了生产3-芳基苯并呋喃酮的连续连续流动系统。从2,4-二叔丁基苯酚和乙醛酸一水合物开始,最初的环缩合和随后的Friedel-Crafts烷基化均由相同的多相催化剂催化,Amberlyst-15H.催化剂对这两个步骤都有很好的寿命,并且能够在不停用的情况下恢复和重复使用几次运行。通过使用已建立的流量系统,5,7-二叔丁基-3-(3,4-二甲基苯基)-3H-苯并呋喃-2-酮(IrganoxHP-136),这是一种商业抗氧化剂,以88%的两步收率制备。与各种芳族化合物的反应在流动条件下进行良好,以高产率提供3-芳基苯并呋喃酮衍生物,并具有良好的官能团相容性。
    A sequential continuous-flow system to produce 3-aryl benzofuranones was developed. Starting from 2,4-di-tert-butylphenol and glyoxylic acid monohydrate, both the initial cyclocondensation and the subsequent Friedel-Crafts alkylation were catalyzed by the same heterogeneous catalyst, Amberlyst-15H. The catalyst has a promising life-time for these two steps, and it was able to be recovered and reused for several runs without deactivation. By using the established flow system, 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one (Irganox HP-136), which is a commercial antioxidant, was prepared in 88% two-step yield. Reactions with various aromatic compounds proceeded well under flow conditions to afford 3-aryl benzo-furanone derivatives in high yields with good functional group compatibility.
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  • 文章类型: Journal Article
    A continuous electrocoagulation reactor, with curved electrodes, polarity switch, and cylindrical geometry, was used for emulsified crude oil in water separation. Apparatus novelty consists of an inlet arranged to promote a circular flow regime. The effects of flow rate (2 and 6 mL.s-1), electrical current (2 and 4 A), and distance between electrodes (1.5 and 2.5 cm) were investigated using a full factorial design and statistical analysis. Using 6 mL.s-1 flow rate, 2 A electric current and 2.5 cm electrode distance; 86% oil removal was obtained at a pH < 9.0. For this configuration, the system will process 21.6 L of oily emulsion while consuming 6.92 Wh. Oil removal increased with flow rate, a novel characteristic created by the unusual geometry of the system.
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  • 文章类型: Journal Article
    Cardiac output (CO) measurement by continuous pulmonary artery thermodilution (CO CTD ) has been studied in patients with pulsatile-flow LVADs (left ventricular assist devices), confirming the clinical utility. However, it has not been validated in patients with continuous-flow LVADs. Therefore, the aim of this study was to assess the validity of CO CTD in continuous-flow LVADs. Continuous-flow LVADs were implanted in six miniature pigs for partial assistance of the left ventricle. Both methods of measuring CO-measurement by CO CTD and intermittent pulmonary artery thermodilution, standard technique (CO ITD )-were used in four consecutive moments of the study: before starting the LVAD (basal moment), and with the LVAD started in normovolemia, hypervolemia (fluid overloading), and hypovolemia (shock hemorrhage). At the basal moment, CO CTD and CO ITD were closely correlated (r 2 = 0.97), with a mean bias of -0.13 ± 0.16 L/min and percentage error of 11%. After 15 min of partial support LVAD, CO CTD and CO ITD were closely correlated (r 2 = 0.91), with a mean bias of 0.31 ± 0.35 L/min and percentage error of 20%. After inducing hypervolemia, CO CTD and CO ITD were closely correlated (r 2 = 0.99), with a mean bias of 0.04 ± 0.07 L/min and percentage error of 5%. After inducing hypovolemia, CO CTD and CO ITD were closely correlated (r 2 = 0.74), with a mean bias of 0.08 ± 0.22 L/min and percentage error of 19%. This study shows that continuous pulmonary thermodilution could be an alternative method of monitoring CO in a porcine model with a continuous-flow LVAD.
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  • 文章类型: Journal Article
    通过原位制备方法获得了一种新型的多孔陶瓷片负载镍颗粒反应器。然后将该反应器用于研究硝基芳族化合物和甲基橙的连续流动催化。用XRD对其结构和形貌进行了表征,SEM,XPS,拉曼,元素映射,压汞法和阿基米德原理。多孔陶瓷片负载Ni颗粒反应器在室温下硼氢化钠催化还原对硝基苯酚和甲基橙表现出优异的催化性能。在2.67mL·min-1的注射速度下,对硝基苯酚(5mM)和甲基橙(0.3mM)的转化率均达到近100%。此外,由于多孔陶瓷片可以减少Ni颗粒的聚集,因此在10次循环时间后,它保持了100%的转化率。此外,化学吸附的氧气,镍和多孔陶瓷片之间的强相互作用导致了一种高效的,可回收,和具有成本效益的多功能反应器。所有这些优点为在废水处理和环境毒理学领域实施提供了新的机会。最终,多孔陶瓷片也可以支撑其他金属纳米材料,并用于其他环境催化领域。
    A novel porous ceramic sheet supported nickel particles reactor was obtained by an in-situ preparation method. This reactor was then used to investigate continuous-flow catalysis of nitroaromatic compounds and methyl orange. The details of the structure and morphology were characterized by XRD, SEM, XPS, Raman, element mapping, mercury intrusion method and Archimedes principle. The porous ceramic sheet supported Ni particles reactor exhibited excellent catalytic performance in the catalytic reduction of p-nitrophenol and methyl orange by sodium borohydride at room temperature. Both the conversion of p-nitrophenol (5 mM) and methyl orange (0.3 mM) reached nearly 100% at the injection speed of 2.67 mL·min-1. In addition, it maintained conversions of 100% after 10 recycling time since the porous ceramic sheet could reduce the aggregation for Ni particles. Furthermore, the chemisorbed oxygen, and the strong interaction between Ni and porous ceramic sheet resulted in a highly efficient, recoverable, and cost-effective multifunctional reactor. All of these advantages present new opportunities to be implemented in the field of waste water treatment and environmental toxicology. Ultimately, the porous ceramic sheet could also support other metal nanomaterial, and used in other fields of environmental catalysis.
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  • 文章类型: Journal Article
    UNASSIGNED: Implementation of continuous flow (CF) technology in modern ventricular assist devices (VAD) has afforded a wealth of engineering and design advantages in the development of a total artificial heart (TAH). However, clinical application of CF has created a unique physiologic state, the consequences of which remain largely unknown. We sought to evaluate clinical and biochemical markers of end-organ function in calves supported with biventricular CF VADs for more than 30 days.
    UNASSIGNED: Eight calves survived longer than 30 days following biventriculectomy and implantation of dual CF VADs. Four types of CF pumps were utilized for the study. Serial hematologic and biochemical profiles were drawn as markers for end-organ function, and hemodynamic data-including pump flows and intravascular pressures-were continuously monitored.
    UNASSIGNED: The eight calves survived an average of 58.8 days (range 30-92 days). Two of the calves were electively terminated at the conclusion of the study period, while the remaining animals were euthanized as a result of respiratory distress (n = 2) or impaired pump flows (n = 4). In each case, serial biochemical and hematologic values were suggestive of preserved end-organ function. Six animals successfully participated in treadmill exercise evaluations. No evidence of end-organ damage was encountered upon necropsy or histologic tissue analysis.
    UNASSIGNED: Biventricular CF VAD implantation permits a viable bovine CFTAH model capable of demonstrating long-term survival. After 30 days of completely nonpulsatile flow, cumulative hemodynamic, clinical, biochemical, and histological analyses were consistent with preserved end-organ function, suggesting previously unreported long-term feasibility of a CFTAH design.
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  • 文章类型: Journal Article
    OBJECTIVE: Pump thrombosis (PT) is a detrimental complication of left ventricular assist device (LVAD) therapy. There is no consensus on optimal PT treatment. The aim of this study was to present a treatment strategy for patients with PT.
    METHODS: The hospital records of patients who underwent isolated LVAD implantation between May 2013 and October 2018 were retrospectively evaluated. Pump thrombosis was suspected in the setting of impaired flow/power parameters and haemolysis. Protocols for the management of suspected PT varied by patient presentation. Parameters that increased the PT risk were investigated by dividing the patients into two groups according to the presence of PT. Preoperative and operative data were analysed.
    RESULTS: Pump thrombosis was observed in 20 of 81 patients. All patients with PT presented elevated lactate dehydrogenase levels and higher power and/or low-/high-flow alarm at admission. All patients were treated initially with intravenous unfractionated heparin infusion; three patients did not require further treatment, one patient died due to sudden cardiac arrest, and three patients underwent urgent surgery for LVAD exchange. Thirteen (13) patients received tissue plasminogen activator infusion; eight were discharged without any signs of thrombosis, and three were bridged to transplant. One (1) major bleeding event leading to death was observed. Freedom from second PT was found in 91% cases at 6 months and in 68.2% at 1 year. We found that a larger left ventricle and the type of pump determined the risk of PT.
    CONCLUSIONS: Low-dose thrombolytic therapy should be considered as a feasible treatment option for patients with PT.
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