Ethers

醚类
  • 文章类型: Journal Article
    肟醚是一类含有>C=N-O-R部分的化合物。该部分的存在影响化合物的生物活性。在这次审查中,收集并呈现了具有特定生物活性的肟醚的结构,和杀菌,杀真菌剂,抗抑郁药,抗癌和除草活性,其中,被描述。审查包括目前用作药物的这两种物质(例如,氟伏沙明,Mayzent,ridogrel,恶康唑),以及已经进行了各种生物活性研究的非药物结构。据我们所知,这是对含有这种部分的化合物的生物活性的第一次审查。作者希望这篇综述能激发科学家对这组化合物产生更大的兴趣,因为它构成了一个有趣的研究领域。
    Oxime ethers are a class of compounds containing the >C=N-O-R moiety. The presence of this moiety affects the biological activity of the compounds. In this review, the structures of oxime ethers with specific biological activity have been collected and presented, and bactericidal, fungicidal, antidepressant, anticancer and herbicidal activities, among others, are described. The review includes both those substances that are currently used as drugs (e.g., fluvoxamine, mayzent, ridogrel, oxiconazole), as well as non-drug structures for which various biological activity studies have been conducted. To the best of our knowledge, this is the first review of the biological activity of compounds containing such a moiety. The authors hope that this review will inspire scientists to take a greater interest in this group of compounds, as it constitutes an interesting research area.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    聚乙烯基醚硅氧烷(PVES)具有用于制作精确和准确的牙科印模的理想特性。PVES的尺寸稳定性归因于其母体材料聚醚和聚乙烯基硅氧烷的更好的聚合物性能。随着化学消毒剂的推荐使用越来越受欢迎,人们越来越关注消毒剂对PVES尺寸稳定性的影响。本研究旨在了解PVES在化学消毒剂作用下的行为。
    这些数据是从GoogleScholar检索的研究中收集的,Scopus,和PubMed使用关键字“乙烯基聚醚硅氧烷和消毒”或(乙烯基聚醚硅氧烷或聚乙烯硅氧烷醚或PVES)和(消毒剂或消毒)“的MeSH术语,对出版日期没有任何限制。在数据收集期间观察到PRISMA(系统评价和荟萃分析的首选报告项目)方向,筛选研究,和荟萃分析。检索了主要数据,并使用Harzing的Publish或Perish软件从数据库中批量导出;主要分析在MicrosoftExcel中进行,而效应大小的统计分析,双尾p值,研究之间的异质性使用MetaEssentials进行。使用Hedge'sg值在95%置信水平下使用随机效应模型计算效应大小。使用CochraneQ和I2测量研究之间的异质性。
    由PVES弹性印模材料制成的牙科印模在尺寸稳定性方面没有显著变化。浸入化学消毒剂10分钟与PVES印象尺寸的临床无关变化有关。用次氯酸钠消毒与尺寸的临床显着变化有关,双尾p值为0.049。用2-2.5%戊二醛溶液消毒与任何显着的尺寸变异性无关。
    Polyvinyl ether siloxane (PVES) possesses ideal characteristics for making precise and accurate dental impressions. PVES dimensional stability owes to its better polymeric properties derived from its parent materials poly ethers and polyvinyl siloxanes. As recommended use of chemical disinfecting agents is getting more popular, there is a growing concern associated with the effect of disinfectants on PVES dimensional stability. This study was aimed to understand the PVES behavior when subjected to chemical disinfectants.
    The data was collected from research studies retrieved from Google Scholar, Scopus, and PubMed using MeSH terms of keywords \"vinyl polyether siloxane AND Disinfection\" or (Vinyl polyether siloxane OR polyvinyl siloxane ether OR PVES) AND (disinfectant OR disinfection)\" without any restriction to publication date. The PRISMA (Preferred Reporting Items for Systemic Review and Meta-Analysis) directions were observed during the data collection, screening of studies, and meta-analysis. The primary data were retrieved, and batch exported from databases using Harzing\'s Publish or Perish software; primary analysis was performed in Microsoft Excel, while statistical analysis for effect size, two-tailed p-values, and heterogeneity among studies was performed using Meta Essentials. The effect size was calculated using Hedge\'s g values at the 95% confidence level using the random-effects model. Heterogeneity among studies was measured using the Cochrane Q and I2.
    Dental impressions made from the PVES elastomeric impression materials showed no significant changes in dimensional stability. Immersion in the chemical disinfectant for 10 min was associated with clinically irrelevant changes in the dimensions of the PVES impressions. Disinfection with sodium hypochlorite was associated with clinically significant changes in dimensions, with a two-tailed p-value of 0.049. Disinfection with 2-2.5% glutaraldehyde solution was not associated with any significant dimensional variability.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Meta-Analysis
    FDA发出警告,3岁以下儿童反复和长时间使用吸入性麻醉药可能会增加神经系统损害的风险。然而,缺乏支持这一警告的强有力的临床证据。关于异氟烷的所有临床前证据的系统评价,七氟醚,在幼年实验动物中暴露地氟醚和安氟醚对神经变性和行为的影响可能阐明了这种风险实际上有多严重。在2022年11月23日对PubMed和Embase进行了全面搜索。基于预定义的选择标准,由两个独立的审阅者筛选所获得的参考。有关研究设计和结果数据的数据(Caspase-3和TUNEL用于神经变性,莫里斯水迷宫(MWM),高架加迷宫(EPM),提取开场(OF)和恐惧条件(FC),并计算个体效应大小,随后使用随机效应模型进行汇总。亚组分析是预先定义的,并针对物种进行,性别,麻醉年龄,重复或单次暴露以及结果测量的时间。在19.796个参考文献中,筛选出的324个可以包括在审查中。对于安氟醚,很少有研究进行荟萃分析(n=1)。暴露于七氟醚,异氟烷和地氟烷显著增加Caspase-3水平和TUNEL水平。Further,七氟醚和异氟醚也会导致学习和记忆障碍,增加焦虑。地氟醚对学习和记忆影响不大,对焦虑没有影响.七氟醚和异氟醚对神经变性的长期影响无法分析,因为研究太少。对于行为结果,然而,这是可能的,并显示七氟醚在所有三个相关结局中导致学习和记忆受损,在高架迷宫中导致焦虑增加.对于异氟烷,还观察到学习和记忆受损,但只有足够的数据可用于学习和记忆相关的两个结局.Further,单一暴露于七氟醚或异氟醚会增加神经变性和学习和记忆受损。总之,我们显示了暴露于卤代醚引起神经变性和行为改变的证据。这些影响对于七氟烷和异氟烷最明显,并且在单次暴露后已经存在。迄今为止,还没有足够的研究来评估长期神经变性作用的存在。然而,我们在这篇关于以后生活中行为变化的综述中提供了证据,提示一些永久性的神经退行性改变.总之,与FDA发出的警告相反,我们表明单独暴露于异氟烷和七氟烷会对大脑发育产生负面影响。根据本综述的结果,七氟醚和异氟醚的使用应尽可能限制在这一年轻弱势群体中,直到对长期永久性影响进行更多研究。
    The FDA issued a warning that repeated and prolonged use of inhalational anaesthetics in children younger than 3 years may increase the risk of neurological damage. Robust clinical evidence supporting this warning is however lacking. A systematic review of all preclinical evidence concerning isoflurane, sevoflurane, desflurane and enflurane exposure in young experimental animals on neurodegeneration and behaviour may elucidate how severe this risk actually is PubMed and Embase were comprehensively searched on November 23, 2022. Based on predefined selection criteria the obtained references were screened by two independent reviewers. Data regarding study design and outcome data (Caspase-3 and TUNEL for neurodegeneration, Morris water maze (MWM), Elevated plus maze (EPM), Open field (OF) and Fear conditioning (FC)) were extracted, and individual effect sizes were calculated and subsequently pooled using the random effects model. Subgroup analyses were predefined and conducted for species, sex, age at anesthesia, repeated or single exposure and on time of outcome measurement. Out of the 19.796 references screened 324 could be included in the review. For enflurane there were too few studies to conduct meta-analysis (n = 1). Exposure to sevoflurane, isoflurane and desflurane significantly increases Caspase-3 levels and TUNEL levels. Further, sevoflurane and isoflurane also cause learning and memory impairment, and increase anxiety. Desflurane showed little effect on learning and memory, and no effect on anxiety. Long term effects of sevoflurane and isoflurane on neurodegeneration could not be analysed due to too few studies. For behavioural outcomes, however, this was possible and revealed that sevoflurane caused impaired learning and memory in all three related outcomes and increased anxiety in the elevated plus maze. For isoflurane, impaired learning and memory was observed as well, but only sufficient data was available for two of the learning and memory related outcomes. Further, single exposure to either sevoflurane or isoflurane increased neurodegeneration and impaired learning and memory. In summary, we show evidence that exposure to halogenated ethers causes neurodegeneration and behavioural changes. These effects are most pronounced for sevoflurane and isoflurane and already present after single exposure. To date there are not sufficient studies to estimate the presence of long term neurodegenerative effects. Nevertheless, we provide evidence in this review of behavioral changes later in life, suggesting some permanent neurodegenerative changes. Altogether, In contrast to the warning issued by the FDA we show that already single exposure to isoflurane and sevoflurane negatively affects brain development. Based on the results of this review use of sevoflurane and isoflurane should be restrained as much as possible in this young vulnerable group, until more research on the long term permanent effects have been conducted.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Review
    氟烷基醚(醚-PFAS),作为逐步淘汰的全氟烷基物质和全氟烷基物质(PFAS)的替代品,由于它们在水生环境中无处不在的检测以及它们在持久性和毒性方面与传统PFAS的相似性,因此引起了越来越多的关注。在这次审查中,综述了醚-PFASs在土壤生态系统中的来源、分布及其对土壤微生物群落的毒性影响。介绍了醚-PFASs的植物吸收和生物积累潜力,并讨论了其摄取和易位的各种影响因素。为了响应醚-PFAS,相应的植物毒性作用,如种子发芽,植物生长,光合作用,氧化损伤,抗氧化酶活性,和遗传毒性,被系统地阐明。最后,强调了当前的知识差距和未来的研究前景。这篇综述的发现将增进我们对土壤-植物系统中的环境行为和醚-PFAS的影响的理解,并有助于探索醚-PFAS修复的策略,以最大程度地减少其不利毒性。
    Fluoroalkylethers (ether-PFASs), as alternatives to phased-out per- and perfluoroalkyl substances (PFASs), have attracted mounting attention due to their ubiquitous detection in aquatic environment and their similarity to legacy PFASs in terms of persistence and toxicity. In this review, the sources and distribution of ether-PFASs in soil ecosystem as well as their toxic impacts on soil microbial community are summarized. The plant uptake and bioaccumulation potential of ether-PFASs are presented, and a wide range of the influencing factors for their uptake and translocation is discussed. In response to ether-PFASs, the corresponding phytotoxic effects, such as seed germination, plant growth, photosynthesis, oxidative damage, antioxidant enzymes activities, and genotoxicity, are systematically elucidated. Finally, the current knowledge gaps and future research prospective are highlighted. The findings of this review will advance our understanding for the environmental behavior and implications ether-PFASs in soil-plant systems and help explore the strategies for ether-PFASs remediation to minimize their adverse toxicity.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    目的:本综述的目的是评估聚醚醚酮(PEEK)在正畸中的应用。
    方法:通过PubMed对电子数据库执行搜索策略,Scopus,WebofScience,丁香花,Opengrey,Embase,Cochrane图书馆和通过手工或电子搜索确定的记录。使用的关键词是:\"PEEK\"或\"聚醚醚酮\"和\"正畸学\"。文章发表的选定时间为2015年1月至2021年6月。
    结论:由于出色的身体,机械,美学特性和生物相容性,它的低斑块亲和力和弯曲模量接近牙釉质和牙本质,PEEK也可用于正畸。然而,应该做更多的临床研究来找出这种材料的所有优点和缺点。
    OBJECTIVE: The aim of this scoping review was to evaluate the application of polyether-ether-ketone (PEEK) in orthodontics.
    METHODS: Search strategies were executed for electronic databases through PubMed, Scopus, Web of Science, Lilacs, Opengrey, Embase, Cochrane Library and records identified through hand or electronic search. The keywords used were: \"PEEK\" OR \"Polyether-ether-ketone\" AND \"orthodontics\". The period selected of article publication was from January 2015 to June 2021.
    CONCLUSIONS: Due to excellent physical, mechanical, aesthetic properties and biocompatibility, its low plaque affinity and flexural modulus close to enamel and dentin, PEEK can be used also in orthodontics. However, more clinical research should be done to find out all the advantages and disadvantages of this material.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    Poly ether-ether-ketone (PEEK) is a polymer with better lignin biocompatibility than other polymers. It is good for biomedical engineering applications. This research summarises the outcomes of an evaluation conducted on PEEK material composites, such as cellular calcium hydroxyapatite (CHAp) for medical applications. Prospects of PEEK for medical implant are highlighted. Critical analysis and review on 3D printing of PEEK, CHAp and their biological macromolecular behaviours are presented. An electronic search was carried out on Scupos database, Google search and peer-reviewed papers published in the last ten years. Because of the extraordinary strength and biological behaviours of PEEK and its composite of CHAp, 3D-printed PEEK has several biomedical applications, and its biological macromolecular behaviour leads to health sustainability. This work highlights its biological macromolecular behaviours as a bone implant material and the optimum 3D printing process for PEEK and CHAp for medical applications. The current problems with printing PEEK and CHAp are investigated along with their possible uses. Possible solutions to improve the 3D printability of PEEK and CHAp are explained based on scientific mechanisms. This detailed report stands to benefit both scientific community and medical industry to enhance 3D printing concepts for PEEK and CHAp.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    OBJECTIVE: Renal damage secondary to fluoride ions and compound A (CpdA) after sevoflurane anesthesia remains unclear. For safety reasons, some countries still recommend minimum fresh-gas flows (FGFs) with sevoflurane. We review the evidence regarding the intraoperative use of sevoflurane for anesthesia maintenance and postoperative renal function compared with other anesthetic agents used for anesthetic maintenance. Secondarily, we examine the effects of peak plasma fluoride and CpdA levels and the effect of FGF and duration of anesthesia on these parameters.
    METHODS: The databases of MEDLINE (OVID and Pubmed), EMBASE, the Cochrane Library, Health Technology Assessment Database, CINAHL, and Web of Science were searched from inception until 23 April 2020 to identify randomized-controlled trials (RCTs) in humans utilizing sevoflurane or an alternative anesthetic for anesthesia maintenance with subsequent measurements of renal function. Two different paired reviewers independently selected the studies and extracted data. The quality of the evidence was appraised using GRADE recommendations.
    RESULTS: Of 3,766 publications screened, 41 RCTs in human patients were identified. There was no difference between creatinine at 24 hr (21 studies; n = 1,529), or creatinine clearance (CCR) at 24 hr (12 studies; n = 728) in the sevoflurane vs alternative anesthetic groups. Peak fluoride and fluoride measured at 24 hr were higher with sevoflurane compared with other inhaled anesthetics. Subgroup analyses for sevoflurane usage in various contexts showed no significant difference between sevoflurane and alternative anesthetics for creatinine or CCR at 24 hr at varying FGF, duration of exposure, baseline renal function, or absorbent use.
    CONCLUSIONS: We did not find any association between the use of sevoflurane and postoperative renal impairment compared with other agents used for anesthesia maintenance. The scientific basis for recommending higher FGF with the use of sevoflurane needs to be revisited.
    RéSUMé: OBJECTIF: Les lésions rénales secondaires aux ions fluorure et au composé A (CpdA) après une anesthésie au sévoflurane demeurent incertaines. Pour des raisons de sécurité, certains pays recommandent encore des débits de gaz frais (DGF) minimaux lors de l’utilisation du sévoflurane. Nous avons passé en revue les données probantes concernant l’utilisation peropératoire de sévoflurane pour le maintien de l’anesthésie sur la fonction rénale postopératoire comparativement à d’autres agents anesthésiques utilisés pour le maintien de l’anesthésie. En analyse secondaire, nous avons examiné les effets des taux plasmatiques maximaux de fluorure et de CpdA et l’effet du DGF et de la durée de l’anesthésie sur ces paramètres.
    METHODS: Des recherches ont été menées dans les bases de données de MEDLINE (OVID et Pubmed), EMBASE, the Cochrane Library, Health Technology Assessment Database, CINAHL et Web of Science, de leur création jusqu’au 23 avril 2020. Nous y avons identifié les études randomisées contrôlées (ERC) réalisées sur des sujets humains utilisant du sévoflurane ou un agent anesthésique alternatif pour le maintien de l’anesthésie et présentant des mesures subséquentes de la fonction rénale. Deux différents réviseurs appariés ont sélectionné de manière indépendante les études et extrait les données. La qualité des données probantes a été évaluée à l’aide des recommandations GRADE.
    UNASSIGNED: Parmi les 3766 publications passées en revue, 41 ERC réalisées chez des patients humains ont été identifiées. Aucune différence n’a été observée en ce qui touchait à la valeur de créatinine à 24 h (21 études; n = 1529) ou de la clairance de la créatinine (CCR) à 24 h (12 études; n = 728) dans les groupes sévoflurane vs autres anesthésiques. Les taux maximaux de fluorure et le fluorure mesuré à 24 h étaient plus élevés lors de l’utilisation de sévoflurane que d’autres agents anesthésiques halogénés. Les analyses de sous-groupe portant sur l’utilisation du sévoflurane dans divers contextes n’ont démontré aucune différence significative entre le sévoflurane et les autres anesthésiques en matière de valeur de créatinine ou de CCR à 24 h selon différents DGF, durées d’exposition, fonctions rénales de base ou absorbants.
    CONCLUSIONS: Nous n’avons pas trouvé d’association entre l’utilisation du sévoflurane et des détériorations de la fonction rénale postopératoires par rapport aux autres agents utilisés pour le maintien de l’anesthésie. Les raisons scientifiques sur lesquelles repose la recommandation d’un DGF plus élevé lors de l’utilisation de sévoflurane doivent être réexaminées.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    燃料含氧化合物(FOs)主要是醚或醇,它们添加到汽油中以提高辛烷值或使燃料燃烧过程随着氧气含量的增加而更加“清洁”,或获得两种效果的组合。F0是水溶性的,在环境中具有高流动性,即使在非常低的浓度下存在,也会降低水的质量,使其由于其令人反感的味道和/或气味而变得不安全或令人不快。因此,由于它们很少具有生物降解性和生物危害性,因此对环境样品中的痕量进行测定非常重要。仪器如气相色谱,傅里叶变换红外光谱和离子迁移谱主要用于FOs的测定。然而,确定此类含氧化合物的主要挑战涉及适当的样品制备。稀释或复杂样品通常需要特定处理以确保在检测之前有效富集FOs。用于此目的的主要技术是吹扫和捕集,膜提取,固相微萃取。本文对环境样品中FOs的提取/预浓缩技术和分析方法进行了全面评估。详细讨论了每种方法的优缺点以及对当前可用方法的关键评估。
    Fuel oxygenates (FOs) are mainly ethers or alcohols which are added to gasoline either to boost the octane number or to make the fuel burning process more \"cleaner\" with increasing the oxygen content, or to obtain a combination of both effects. FOs are water soluble with high mobility in the environment which presence even at very low concentrations lower the quality of water making it unsafe or unpleasant due to their objectionable taste and/or odor. Thus, their determination at trace in environmental samples is of high importance because of their sparingly biodegradability and their biological hazards. Instruments such as gas chromatography, Fourier transform infrared spectroscopy and ion mobility spectrometry are mainly used for the determination of FOs. However, the main challenge for determination of such oxygenates relates to proper sample preparation. Dilute or complex samples often demand a specific treatment to ensure effective enrichment of FOs before their detection. The main techniques used for this purpose are purge and trap, membrane extraction, and solid phase microextraction. This review presents a comprehensive evaluation of extraction/preconcentration techniques and analytical methods for determination of FOs in environmental samples. Advantages and disadvantages of each method are discussed in details along with critical evaluation of currently available methods.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    随着时间的推移,各种材料已被用于修复牙科。然而,由于科学和知识的发展,新材料正被带到最前沿。聚醚醚酮(PEEK)是一种在牙科领域具有许多潜在应用的聚合物。PEEK的使用在牙科实践中变得越来越普遍;其有利的特性使其成为修复性牙科中引人注目的替代生物材料。当前的趋势是使用在复杂的口腔环境中表现出先进性能的无金属修复体和生物材料。本文介绍并总结了PEEK在当代牙科中的临床应用。
    Various materials have been used over time in prosthetic dentistry. However, due to the evolution of science and knowledge, new materials are being brought to the forefront. Polyether ether ketone (PEEK) is a polymer with many potential applications in dentistry. The use of PEEK has become increasingly more common in dental practice; its favorable properties have made it a compelling alternative biomaterial in restorative dentistry. The current trend is moving towards the use of metal-free restorations and biomaterials which exhibit advanced properties in the complex oral environment. This review paper presents and summarizes clinical applications of PEEK in contemporary dentistry.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    淀粉几十年来一直是一个取之不尽的研究课题。这是一个便宜的,易得的材料,在食品和加工业中具有广泛的应用。研究人员不断尝试通过不同的修饰程序来改善其性能并扩展其应用。这种观点中最常用的是它们的化学修饰,其中有机酸最近引起了最大的关注,特别是关于淀粉在食品工业中的应用。即,有机酸天然存在于许多食用植物中,其中许多通常被认为是安全的(GRAS),这使它们成为食品工业淀粉的理想改性剂。这篇综述的目的是对淀粉酯化的研究进展进行简短的文献综述,醚化,交联,有机酸及其衍生物的双重修饰。
    Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号