Fiber

光纤
  • 文章类型: Journal Article
    黄麻纤维是最通用的天然纤维之一,被广泛用作包装的原料,纺织品,和建筑;并作为重型应用的复合材料的增强材料。在过去,酸水解和通过球磨法进行的机械处理在从天然植物纤维中提取纤维素纳米纤维(CNFs)中很常见。然而,使用那些方法存在一些缺点,其中当进行酸水解法时将产生大量的酸性废水。
    这项研究调查了化学和机械方法结合在黄麻CNF提取中的潜在用途。通过这种方法,黄麻纤维首先用氢氧化钠(NaOH)化学处理,亚氯酸钠(NaClO2)和硫酸(H2SO4)去除非纤维素元素,然后使用行星式球磨机进行机械研磨。
    在场发射扫描电子显微镜(FESEM)下观察所获得的CNF的形状和尺寸。这项研究表明,黄麻CNFs是通过化学和机械处理方法的组合成功提取的,其中获得的CNFs表现出光滑的纤维形态,直径为23nm,长度为150-200nm。
    黄麻纤维素纳米纤维通过化学和机械处理的组合成功地从黄麻原纤维中抽出。获得的结果证实,化学机械方法是分离CNF的有效技术,并解释了其作为增强材料的潜在用途。
    UNASSIGNED: Jute fiber is one of the most versatile natural fibers that is widely used as a raw material for packaging, textiles, and construction; and as a reinforcement in composite materials for heavy-duty applications. In the past, acid hydrolysis and mechanical treatment via the ball milling method were common in the extraction of cellulose nanofiber (CNFs) from natural plant fibers. However, there are some drawbacks of using those methods where there will be a huge quantity of acidic wastewater generated when the acid hydrolysis method is performed.
    UNASSIGNED: This study investigated the potential use of a combination of chemical and mechanical methods in the extraction of jute CNFs. Through this method, the jute fibers were first chemically treated using sodium hydroxide (NaOH), sodium chlorite (NaClO 2) and sulphuric acid (H 2SO 4) to remove the non-cellulosic elements followed by mechanical milling by using a planetary ball mill.
    UNASSIGNED: The shape and size of the obtained CNFs were observed under a field emission scanning electron microscope (FESEM). This study revealed that jute CNFs were successfully extracted through the combination of chemical and mechanical treatment methods where the obtained CNFs reveal themselves in smooth fibrous morphology with a diameter of 23 nm and 150-200nm in length.
    UNASSIGNED: Jute cellulose nanofibers were successfully drawn out from raw jute fibers by means of a combination of chemical and mechanical treatment. The results obtained confirmed that the chemomechanical method is an effective technique for isolating the CNFs and its potential use as reinforcement material was explained.
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  • 文章类型: Journal Article
    由于其多酚含量高,黑米在良好的营养中起着重要作用;然而,这些抗氧化剂化合物受到大米消费所需的热处理的影响。这项工作的目的是研究烹饪如何影响Artemide黑米的成分,比较创新的方法,比如sousvide,与传统的国内技术(意大利调味饭和抓饭)。蛋白质和骨灰不受烹饪的影响,除了抓饭,观察到42%的灰分减少;在所有烹饪方法之后,纤维含量增加,意大利调味饭增加了29%。抗氧化活性,总多酚,花青素和原花青素平均减少了40%,34%,43%和39%,分别。个体花色苷减少,虽然酚酸和其他类黄酮表现出不同的行为,也取决于是否以自由或约束形式考虑。在99°C的温度下,sousvide煮熟的米饭中的Cyanidin-3-O-葡萄糖苷减少了56%,在89°C下,意大利调味饭和固态米饭中只有45%和37%,分别。传统的意大利调味饭制备和在89°C下的创新sousvide烹饪也保持了最高的抗氧化多酚含量,相对于原料黑米,节省了63%的抗氧化活性。Concluding,这些最后的技术可以建议更好地保存生物活性化合物。
    Due to its high polyphenol content, black rice plays a significant role in good nutrition; however, these antioxidant compounds are affected by heat treatments required for the rice consumption. The aim of this work was to investigate how cooking affects the composition of Artemide black rice, comparing innovative methods, such as sous vide, with traditional domestic techniques (risotto and pilaf). Proteins and ashes were not affected by cooking, except for pilaf rice, where a 42 % ashes decrease was observed; fiber content increased after all cooking methods, reaching a 29 % increase in the risotto. Antioxidant activity, total polyphenols, anthocyanins and proanthocyanidins were reduced on average of 40 %, 34 %, 43 % and 39 %, respectively. Individual anthocyanins decreased, while phenolic acids and other flavonoids presented different behaviours, also depending if considered in their free or bound form. Cyanidin-3-O-glucoside was reduced up to 56 % in the sous vide cooked rice at 99 °C, and only by 45 % and 37 % in the risotto and sous vide cooked rice at 89 °C, respectively. Traditional risotto preparation and the innovative sous vide cooking at 89 °C also maintained the highest antioxidant polyphenols content, saving 63 % of the antioxidant activity in respect to the raw black rice. Concluding, these last techniques can be suggested for a better preservation of bioactive compounds.
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  • 文章类型: Journal Article
    背景:补充龙舌兰韦伯蓝品种果聚糖是功能性便秘(FC)的可行治疗选择。然而,其对结肠功能的影响尚未研究。这项研究使用无线运动胶囊(WMC)评估了FC患者在补充不同纤维治疗前后的整个肠道运输时间(WGTT)和区域运输时间。
    方法:对从随机,比较龙舌兰果聚糖和车前草的双盲临床试验。WGTT,区域运输时间,收缩性,在补充纤维之前和之后使用WMC测量pH。使用非参数检验进行比较。
    结果:对20例FC患者进行了评估,年龄中位数为39岁(25-54岁),18人(90%)是女性。每个干预组纳入5例患者。两组间WGTT或区域转运时间无变化(p>0.05)。同样,各组之间区域或一般收缩力的变化无差异(p>0.05)。在补充纤维之前和之后,盲肠pH曲线在各组之间没有差异(p>0.05)。两组之间的临床反应百分比和排便一致性相似。
    结论:FC对纤维挑战表现出临床反应,不管管理的干预。然而,这种反应与收缩力或区域转运时间的改善无关.我们推测,还有其他机制可以通过纤维消耗来改善FC。
    BACKGROUND: Supplementation with the Agave tequilana Weber blue variety fructans is a feasible treatment option for functional constipation (FC). However, its effects on colonic function have not yet been studied. This study assessed whole gut transit time (WGTT) and regional transit time using a wireless motility capsule (WMC) before and after supplementation with different fiber treatments in patients with FC.
    METHODS: A secondary analysis was performed on data collected from a randomized, double-blind clinical trial comparing agave fructans with psyllium plantago. WGTT, regional transit time, contractility, and pH were measured using WMC before and after fiber supplementation. Comparisons were performed using nonparametric tests.
    RESULTS: Twenty patients with FC were evaluated, with a median age of 39 (25-54 years), and 18 (90%) were women. Five patients were included in each intervention group. There were no changes in WGTT or regional transit times between the groups (p > 0.05). Similarly, there were no differences in the changes experienced by regional or general contractility among the groups (p > 0.05). The cecal pH profile did not differ between the groups before and after fiber supplementation (p > 0.05). The percentages of clinical responses and consistency of bowel movements between the groups were similar.
    CONCLUSIONS: FC presents a clinical response to a fiber challenge, regardless of the administered intervention. However, this response was not associated with improvement in contractility or regional transit time. We speculate that there are other mechanisms by which fiber consumption may improve FC.
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  • 文章类型: Journal Article
    生物电子学提供生命系统和人造设备之间的有效信息交换,作为融合生物学和技术领域的重要桥梁。使用功能性纤维作为构建块,生物电子学可以分层组装,具有不同规模的巨大设计可能性,增强其特定应用的生物整合,人体工程学,和可持续性。在这项工作中,作者通过反思生物电子纤维元件的制造方法和关键性能指标,回顾了生物电子纤维元件的最新发展,包括生命周期可持续性,环境机电性能,和功能适应性。通过深入研究与物理部署相关的挑战,探索适应性的创新设计策略,我们提出了通过纤维构建块的生物电子学未来发展的途径,提高“物联网纤维”对市场就绪型生物电子产品的潜力,最大限度地减少对环境的影响。
    Bioelectronics provide efficient information exchange between living systems and man-made devices, acting as a vital bridge in merging the domains of biology and technology. Using functional fibers as building blocks, bioelectronics could be hierarchically assembled with vast design possibilities across different scales, enhancing their application-specific biointegration, ergonomics, and sustainability. In this work, the authors review recent developments in bioelectronic fiber elements by reflecting on their fabrication approaches and key performance indicators, including the life cycle sustainability, environmental electromechanical performance, and functional adaptabilities. By delving into the challenges associated with physical deployment and exploring innovative design strategies for adaptability, we propose avenues for future development of bioelectronics via fiber building blocks, boosting the potential of \"Fiber of Things\" for market-ready bioelectronic products with minimized environmental impact.
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  • 文章类型: Journal Article
    背景:大量营养素消费与2型糖尿病(T2D)风险之间的关系仍然模棱两可。这里,我们调查了西亚人群中大量营养素摄入的数量和质量是否与T2D发病率相关.
    方法:无T2D的成年人(n=2457,平均年龄38.5±13.6岁,54.2%的妇女)参加了德黑兰脂质和葡萄糖研究的第三个检查周期(2005-2008年),平均随访8.6年。我们估计了常量营养素质量指数(MQI),其各个子指数(碳水化合物质量指数(CQI),脂肪质量指数(FQI),和健康平板蛋白质质量指数(HPPQI)),以及大量营养素的数量。与大量营养素数量相关的T2D风险,质量,并使用Cox比例风险模型对其联合效应进行检验,校正了已知的T2D危险因素.
    结果:在研究随访期间,记录了257例T2D事件。MQI和CQI最高三分位数的个体的T2D风险比最低三分位数的个体低27%(HR=0.73,95%CI=0.54,0.98)和29%(HR=0.71,95%CI=0.51-0.99)。中间HPPQI三元组的T2D发生率比最低三元组低35%(HR=0.65,95%CI=0.47,0.89)。多变量调整模型显示,碳水化合物摄入量中和最高三元的个体比最低三元的个体低32%(HR=0.68,95%CI=0.49-0.95)和26%(HR=0.74,95%CI=0.55-1.00)T2D风险。大量的,高质量的碳水化合物饮食(CQI≥13的碳水化合物能量≥58.5%)和低血糖指数(GI),高纤维饮食(GI<55和纤维≥25g/d)与T2D风险降低34%(HR=0.66,95%CI=0.47,0.93)和42%(HR=0.58,95%CI=0.38,0.90)相关,分别。
    结论:具有较高碳水化合物质量的饮食可能与较低的T2D发病率相关,特别是当碳水化合物的数量也很高时。
    BACKGROUND: The association between macronutrient consumption and the risk of type 2 diabetes (T2D) remains equivocal. Here, we investigated whether the quantity and quality of macronutrient intake are associated with T2D incidence in a West Asian population.
    METHODS: T2D-free adults (n = 2457, mean age 38.5 ± 13.6 years, 54.2% women) who participated in the third examination cycle (2005-2008) of the Tehran Lipid and Glucose Study were followed for a median of 8.6 years. We estimated the macronutrient quality index (MQI), its individual sub-indices (carbohydrate quality index (CQI), fat quality index (FQI), and healthy plate protein quality index (HPPQI)), as well as the macronutrient quantity. The risk of T2D in relation to macronutrient quantity, quality, and their combined effects was examined using Cox proportional hazard models adjusted for known risk factors for T2D.
    RESULTS: During the study follow-up, 257 incident cases of T2D were documented. Individuals in the highest tertiles of MQI and CQI had a 27% (HR = 0.73, 95% CI = 0.54, 0.98) and 29% (HR = 0.71, 95% CI = 0.51-0.99) lower T2D risk than those in the lowest tertiles. The T2D incidence was 35% lower in the middle HPPQI tertile than in the lowest (HR = 0.65, 95% CI = 0.47, 0.89). The multivariable adjusted model showed that individuals in the middle and highest tertiles of carbohydrate intake had 32% (HR = 0.68, 95% CI = 0.49-0.95) and 26% (HR = 0.74, 95% CI = 0.55-1.00) lower risks of T2D than individuals in the lowest tertile. A high-quantity, high-quality carbohydrate diet (≥ 58.5% of energy from carbohydrate with a CQI ≥ 13) and a low-glycemic index (GI), high-fiber diet (GI < 55 and fiber ≥ 25 g/d) were related to a reduced risk of T2D by 34% (HR = 0.66, 95% CI = 0.47, 0.93) and 42% (HR = 0.58, 95% CI = 0.38, 0.90), respectively.
    CONCLUSIONS: A diet with a higher carbohydrate quality may be associated with a lower T2D incidence, particularly when the carbohydrate quantity is also high.
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  • 文章类型: Journal Article
    高强度和高韧性的良好结合是坚固生物材料设计中的长期挑战。同时,坚固的生物材料在室温下在光的触发下几乎没有表现出快速和显著的机械性能变化。这些限制了生物材料在某些特定领域的应用。这里,光响应藻酸盐纤维是通过使用设计的含偶氮苯的表面活性剂作为交联藻酸盐多糖链的柔性接触点来制造的,通过增强塑料应变和通过偶氮苯异构化光调制力学获得高力学。通过将分子运动转化为宏观尺度的机械性能变化,这种藻酸盐纤维在力学上实现可逆的光调制。它们的断裂强度和韧性可以分别从732MPa和112MJm-3到299MPa和27MJm-3进行光调制,导致在开发的智能生物材料中出现较高的机械变化。具有对pH和温度具有良好耐受性的优点,对光线的快速响应,良好的生物相容性,报告的纤维将适合在各种应用场景中作为新的智能生物材料。这项研究为获得高强度和高韧性的光响应生物材料提供了一种新的设计策略。
    The good combination of high strength and high toughness is a long-standing challenge in the design of robust biomaterials. Meanwhile, robust biomaterials hardly perform fast and significant mechanical property changes under the trigger of light at room temperature. These limit the application of biomaterials in some specific areas. Here, photoresponsive alginate fibers are fabricated by using the designed azobenzene-containing surfactant as flexible contact point for cross-linking polysaccharide chains of alginate, which gain high mechanics through reinforced plastic strain and photo-modulating mechanics through isomerization of azobenzene. By transferring molecular motion into macro-scale mechanical property changes, such alginate fibers achieve reversible photo-modulations on the mechanics. Their breaking strength and toughness can be photo-modulated from 732 MPa and 112 MJ m-3 to 299 MPa and 27 MJ m-3, respectively, leading to record high mechanical changes among the developed smart biomaterials. With merits of good tolerance to pH and temperature, fast response to light, and good biocompatibility, the reported fibers will be suitable for working in various application scenarios as new smart biomaterials. This study provides a new design strategy for gaining highly-strong and highly-tough photoresponsive biomaterials.
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  • 文章类型: Journal Article
    纤维增强复合材料通常暴露在与水分和溶液相关的环境中,导致吸收,这导致了本体树脂的变化,纤维-基质界面,甚至纤维本身。有关吸收行为和扩散机制和特性的知识对于更好地了解这些材料对通过服务而面临的环境暴露的响应,以通过选择成分来开发更好的材料以及对长期耐久性的预测至关重要。本文回顾了吸收机制和后续反应的各个方面,以及描述吸附过程的模型,目的是全面了解与水分吸收有关的现象和特征,例如吸收速率,扩散和弛豫/劣化常数,政权过渡,和整体反应。
    Fiber-reinforced composites are commonly exposed to environments associated with moisture and solution, resulting in uptake, which causes changes in the bulk resin, the fiber-matrix interface, and even the fiber itself. Knowledge about uptake behavior and diffusion mechanisms and characteristics are critical to better understanding the response of these materials to environmental exposure faced through service to developing better materials through selection of constituents and to the prediction of long-term durability. This paper reviews aspects of uptake mechanisms and subsequent response, as well as models that describe the sorption process, with the aim of providing a comprehensive understanding of moisture-uptake-related phenomena and characteristics such as uptake rate, diffusion and relaxation/deterioration constants, transitions in regimes, and overall response.
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  • 文章类型: Journal Article
    科学证据表明,饮食模式是心理健康的关键环境决定因素。饮食成分可以改变表观遗传模式,从而改变各种心理健康状况中相关遗传变异的基因表达。在目前的工作中,我们描述了膳食纤维的一些营养基因组效应,酚类化合物(植物次生代谢产物),和脂肪酸对心理健康的影响,强调它们可能与遗传和表观遗传方面的相互作用。益生元,通过它们对肠道微生物群的影响,与调节神经内分泌对压力的反应以及促进积极情绪的处理有关。一些遗传和表观遗传机制包括5-羟色胺神经递质系统(TPH1基因)和脑源性神经营养因子(抑制组蛋白脱乙酰酶)。酚类化合物的消耗在神经认知领域发挥积极作用。表明遗传和表观遗传因素参与的证据主要来自动物模型,强调通过miRNA和甲基转移酶的表观遗传机制的作用以及对凋亡相关基因表达的影响。长链n-3脂肪酸(EPA和DHA)主要与精神病和情绪障碍有关,但是遗传和表观遗传证据很少。需要促进对这些相互作用的遗传和表观遗传基础的研究,以朝着精确和个性化的医学方法迈进。
    Scientific evidence shows that dietary patterns are a key environmental determinant of mental health. Dietary constituents can modify epigenetic patterns and thus the gene expression of relevant genetic variants in various mental health conditions. In the present work, we describe some nutrigenomic effects of dietary fiber, phenolic compounds (plant secondary metabolites), and fatty acids on mental health outcomes, with emphasis on their possible interactions with genetic and epigenetic aspects. Prebiotics, through their effects on the gut microbiota, have been associated with modulation in the neuroendocrine response to stress and the facilitation of the processing of positive emotions. Some of the genetic and epigenetic mechanisms include the serotonin neurotransmitter system (TPH1 gene) and the brain-derived neurotrophic factor (inhibition of histone deacetylases). The consumption of phenolic compounds exerts a positive role in neurocognitive domains. The evidence showing the involvement of genetic and epigenetic factors comes mainly from animal models, highlighting the role of epigenetic mechanisms through miRNAs and methyltransferases as well as the effect on the expression of apoptotic-related genes. Long-chain n-3 fatty acids (EPA and DHA) have been mainly related to psychotic and mood disorders, but the genetic and epigenetic evidence is scarce. Studies on the genetic and epigenetic basis of these interactions need to be promoted to move towards a precision and personalized approach to medicine.
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  • 文章类型: Journal Article
    为了在即将到来的儿童慢性肾脏病(CKD)随机临床试验中促进改进试验设计,了解尿毒症毒素的患者内部和患者间的变异性及其营养,治疗和患者相关的混杂因素至关重要.在这项研究中,在诊断为CKD的儿童的纵向队列中,对选择的尿毒症毒素的患者内和患者间的变异性进行了评估。使用组内相关系数(ICC)和患者内部变异系数(CV)。随后,人体测量学的贡献,估计肾小球滤过率(eGFR),膳食纤维和蛋白质,并评估了(预防性)抗生素对尿毒症毒素变异性的使用。根据对62名儿童(每位患者平均7次就诊;9.4±5.3岁;68%的男性;eGFR38.5[23.1;64.0]mL/min/1.73m2)的403次观察,最长时间为2年,我们发现,尤其是蛋白结合型尿毒症毒素(PBUT)的患者内部变异性较高(ICC<0.7;患者内部CV37-67%).此外,eGFR被确定为大多数溶质的患者内部和患者间变异性的主要贡献者,而孩子的人体测量学的影响,纤维和蛋白质的摄入量,抗生素对尿毒症毒素浓度的变异性是有限的。基于这些发现,我们建议在未来进行干预研究,尝试降低尿毒症毒素水平,以选择eGFR范围较窄的(非透析)CKD研究人群.由于所选干预措施的预期效果应超过所选尿毒症毒素的患者间变异性,狭窄的eGFR范围可能有助于改进试验设计.
    To promote improved trial design in upcoming randomized clinical trials in childhood chronic kidney disease (CKD), insight in the within- and inter-patient variability of uremic toxins with its nutritional, treatment- and patient-related confounding factors is of utmost importance. In this study, the within- and inter-patient variability of a selection of uremic toxins in a longitudinal cohort of children diagnosed with CKD was assessed, using the intraclass correlation coefficient (ICC) and the within-patient coefficient of variation (CV). Subsequently, the contribution of anthropometry, estimated glomerular filtration rate (eGFR), dietary fiber and protein, and use of (prophylactic) antibiotics to uremic toxin variability was evaluated. Based on 403 observations from 62 children (median seven visits per patient; 9.4 ± 5.3 years; 68% males; eGFR 38.5 [23.1; 64.0] mL/min/1.73 m2) collected over a maximum of 2 years, we found that the within-patient variability is high for especially protein-bound uremic toxins (PBUTs) (ICC < 0.7; within-patient CV 37-67%). Moreover, eGFR was identified as a predominant contributor to the within- and inter-patient variability for the majority of solutes, while the impact of the child\'s anthropometry, fiber and protein intake, and antibiotics on the variability of uremic toxin concentrations was limited. Based on these findings, we would recommend future intervention studies that attempt to decrease uremic toxin levels to select a (non-dialysis) CKD study population with a narrow eGFR range. As the expected effect of the selected intervention should exceed the inter-patient variability of the selected uremic toxins, a narrow eGFR range might aid in improving the trial design.
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  • 文章类型: Journal Article
    植物纤维很结实,健壮,灵活,多才多艺,可再生,可持续,使它们对许多应用有价值。来自植物的纤维现已用于生物医学应用,作为生物复合材料的增强材料,以增强复合生物材料的机械特性,包括刚性。抗拉强度,和耐力。在生物装置中探索了具有混合成分的增强复合材料,以在骨科中进行前瞻性利用,假肢,组织制造,和外科敷料。这篇综述概述了植物纤维,包括他们的特点,影响变量,和众多的应用。本文探讨了几种使用常见的合成复合材料创建方法,可持续纤维和由此产生的生物材料的独特特征。本文还分析了复合杂种的许多实例及其在生物领域的应用。总结了结果,并提出了潜在的改进建议。当前的研究主要考察了这个概念,规格,效率,以及由植物纤维制成的具有混合特性的复合材料的潜在进步。
    Plant fibers are strong, robust, flexible, versatile, renewable, and sustainable, making them valuable for many applications. Fibers from plants are now utilized in biomedical applications as reinforcements for biological composites to enhance the mechanical characteristics of composite biological materials including rigidity, tensile strength, and endurance. Reinforcement composites with hybrid components were explored in biodevices for prospective utilization in orthopedics, prosthetics, tissue fabrication, and surgical dressings. This review presents an overview of plant fibers, including their characteristics, influencing variables, and numerous applications. The text explores several methods for creating synthetic composites using common, sustainable fibers and the distinct characteristics of the resulting biological materials. The text also analyses many instances of composite hybrids and their application in the biological field. The results are summarised and suggestions for potential improvements are presented. The current research primarily examines the concept, specifications, efficiency, and potential advancements of composites with hybrid characteristics made from plant fibers.
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