Dispersion method

  • 文章类型: Journal Article
    为了获得最佳的质谱鉴定结果,以便在临床实践中使用最合适的方法,我们探索了不同种类和形态的丝状真菌的最佳预处理方法。用甲酸夹心法处理98株真菌,分散方法,提取方法,和其他使用介质元素质谱仪(EXS3000)作为平台的方法。每个菌株都有三个目标,并比较不同预处理方法下的识别率和置信度差异,以评估这些方法的识别效果。对甲酸夹心法预处理后的98株丝状真菌进行质谱鉴定,分散方法,提取方法为85.71%,82.65%,75.51%,分别。甲酸夹心法的识别率明显高于其他两种方法(P<0005),具有最好的识别能力,获得的置信度也高于其他两种方法。利用甲酸夹心法进行丝状真菌的质谱鉴定可以取得理想的鉴定结果,适用于常规实验室中丝状真菌的质谱鉴定。
    In order to obtain the best mass spectrometry identification results for using the most appropriate methods in clinical practice, we explore the optimal pretreatment methods for different species and morphologies of filamentous fungi. 98 fungal strains were treated with formic acid sandwich method, dispersion method, extraction method, and other methods using a medium element mass spectrometer (EXS3000) as a platform. Each strain had three targets, and the identification rates and confidence differences under different pre-treatment methods were compared to evaluate the identification effects of these methods. The mass spectrometry identification rates of 98 filamentous fungi obtained after pre-treatment with formic acid sandwich method, dispersion method, and extraction method were 85.71%, 82.65%, and 75.51%, respectively. The identification rate of the formic acid sandwich method was significantly higher than the other two methods (P < 0 005) has the best identification ability and the obtained confidence is also higher than the other two methods. The use of formic acid sandwich method for mass spectrometry identification of filamentous fungi can achieve ideal identification results, which is suitable for mass spectrometry identification of filamentous fungi in conventional laboratories.
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  • 文章类型: Journal Article
    纳米聚合物化合物的发展有几个原因,比如改善身体,机械,和化学性质,延长寿命,降低成本,减少对环境的负面影响。纳米复合材料中两种橡胶和矿物纳米填料的相容性是一个需要研究的挑战,以及纳米填料对形态的影响,物理,和机械性能应进行相应的研究。在这项研究中,将碳酸钙纳米颗粒添加到包含天然橡胶(NR)的聚合物化合物中,丁苯橡胶(SBR),硫化促进剂,和其他添加剂。为了在聚合物基质中混合纳米颗粒,使用了各种方法,包括在甲苯和W410溶剂中的溶剂法和硬脂酸对纳米碳酸钙的表面改性。纳米复合材料样品中分散纳米颗粒对形貌的影响,固化特性,并对力学性能进行了研究。通过X射线衍射(XRD)分析和场发射扫描电子显微镜(FESEM)确定了样品的形貌。纳米复合材料的粒径约为34nm,晶板之间的层间间距从2.81nm增加到3.03nm。这些结果表明纳米粒子的均匀分散,特别是最佳含量为3.52%,在通过所有混合方法制备的化合物中,在纳米复合材料中没有观察到团聚。纳米复合材料固化表征的结果表明,随着纳米颗粒的添加,在聚合物链中形成强键,和固化性能得到改善。在分散方法中,用溶剂方法W410观察到固化性能的最高百分比改善。为了评估碳酸钙纳米颗粒的添加和分散方法对改善机械性能的影响,拉伸,眼泪,硬度,并进行了回弹弹性试验。在拉伸试验中,表面改性方法表现出最高的极限应力增强(80%),其次是W410法(64%)和甲苯法(63.7%)。撕裂强度改善在W410溶剂样品中最高(80%),其次是表面改性方法(57%)和溶剂-甲苯法(50%)。W410方法产生了最硬的样品,而表面改性样品的硬度最低。CaCO3纳米填料的加入降低了回弹性,W410方法的降幅最大(10.64%),其次是甲苯法(6.38%),并且表面改性的样品显示出最低的降低(4.25%)。结果表明,在W410溶剂法中,纳米复合材料比其他方法更有弹性。此外,对于大多数机械性能,W410方法在改进中产生最大的增长。
    There are several reasons for the development of nanopolymer compounds, such as improving physical, mechanical, and chemical properties, increasing lifespan, reducing costs, and decreasing negative environmental impact. The compatibility of two rubbers and mineral nanofillers in nanocomposites is a challenge that needs to be studied, and the effect of nanofillers on morphological, physical, and mechanical properties should be investigated accordingly. In this study, calcium carbonate nanoparticles were added to a polymer compound that included natural rubber (NR), styrene-butadiene rubber (SBR), vulcanization accelerators, and other additives. For mixing nanoparticles in the polymer matrix, various methods were used, including the solvent method in toluene and W410 solvents and the surface modification of calcium carbonate nanoparticles with stearic acid. The effect of dispersion nanoparticles in nanocomposite specimens on morphology, curing characteristics, and mechanical properties was studied. The morphologies of specimens were determined by X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FESEM). The particle size of the nanocomposite was approximately 34 nm, and the interlayer spacing between crystal plates increased from 2.81 nm to 3.03 nm. These results indicate a uniform dispersion of nanoparticles, specifically with an optimum content of 3.52%, in the compounds prepared through all mixing methods, with no agglomeration observed in the nanocomposites. The results of the nanocomposites\' curing characterization demonstrate that with the addition of nanoparticles, a strong bond is created in the polymer chains, and curing properties are improved. Among the dispersion methods, the highest percentage improvement in curing properties is observed with the solvent method W410. To evaluate the effect of the addition of calcium carbonate nanoparticles and the dispersion method on improving mechanical properties, tensile, tear, hardness, and rebound resilience tests were performed. In tensile tests, the surface modification method showed the highest enhancement in ultimate stress (80%), followed by the W410 method (64%) and toluene method (63.7%). Tear strength improvements were highest in the W410-solvent sample (80%), followed by the surface modification method (57%) and the solvent-toluene method (50%). The W410 method resulted in the hardest samples, while the surface-modified samples had the lowest hardness. The addition of CaCO3 nanofillers reduced rebound resilience, with the W410 method experiencing the largest reduction (10.64%), followed by the toluene method (6.38%), and with the surface-modified samples showing the lowest reduction (4.25%). The results show that in the W410 solvent method, the nanocomposite is more elastic than for other methods. Additionally, for most of the mechanical properties, the W410 method results in the most growth in improvement.
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  • 文章类型: Journal Article
    为了实现对混凝土结构健康的有效监测,在胶凝材料中添加碳纳米管(CNT)为制造具有自感知能力的CNT改性智能混凝土提供了有希望的解决方案。本研究考察了CNT分散方法的影响,水/水泥(W/C)比,和混凝土成分对CNT改性胶凝材料压电性能的影响。三种CNT分散方法(直接混合,十二烷基苯磺酸钠(NaDDBS)和羧甲基纤维素(CMC)表面处理),三个W/C比(0.4、0.5和0.6),和三种混凝土组成成分(纯水泥,水泥/砂,和水泥/砂/粗骨料)被考虑。实验结果表明,经过CMC表面处理的CNT改性胶凝材料对外部载荷具有有效且一致的压电响应。随着W/C比的增加,压电灵敏度显着提高,随着沙子和粗骨料的添加,压电灵敏度逐渐降低。
    In order to achieve effective monitoring of concrete structures for sound structural health, the addition of carbon nanotubes (CNTs) into cementitious materials offers a promising solution for fabricating CNT-modified smart concrete with self-sensing ability. This study investigated the influences of CNT dispersion method, water/cement (W/C) ratio, and concrete constituents on the piezoelectric properties of CNT-modified cementitious materials. Three CNT dispersion methods (direct mixing, sodium dodecyl benzenesulfonate (NaDDBS) and carboxymethyl cellulose (CMC) surface treatment), three W/C ratios (0.4, 0.5, and 0.6), and three concrete constituent compositions (pure cement, cement/sand, and cement/sand/coarse aggregate) were considered. The experimental results showed that CNT-modified cementitious materials with CMC surface treatment had valid and consistent piezoelectric responses to external loading. The piezoelectric sensitivity improved significantly with increased W/C ratio and reduced progressively with the addition of sand and coarse aggregates.
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  • 文章类型: Journal Article
    纳米颗粒由于其大的表面积/体积比和损害细菌细胞膜完整性的潜力而最近作为抗菌剂获得了兴趣。由于其多功能性和抗菌活性,基于石墨烯的材料在生物医学应用中引起了极大的兴趣。在现代技术时代,对生命的最大威胁之一是传染病的普遍性,因为细菌细胞不断更新自己以抵抗抗生素。在这项研究中,GO-Se纳米复合材料已使用聚合物溶液通过简单的分散方法合成。详细研究了纳米复合材料的结构和理化性质。金黄色葡萄球菌,普通变形杆菌,和枯草芽孢杆菌菌株用于研究GO-Se纳米复合材料的抗菌活性。结果表明,合成的纳米复合材料具有良好的抗菌剂功效。紫外-可见光谱,FTIR光谱,HRTEM,XPS,并利用拉曼光谱对制备的GO和GO-Se纳米复合材料进行了分析。
    Nanoparticles have recently gained interest as an anti-bacterial agent due to their large surface area/volume ratio and potential to compromise the integrity of bacterial cell membranes. Due to its versatility and anti-bacterial activity, graphene-based materials have drawn significant interest in biomedical applications. One of the greatest threats to life in the modern technological era is the pervasiveness of infectious diseases since bacteria cells are constantly updating themselves to resist antibiotics. In this presented study, GO-Se nanocomposite has been synthesized using polymer solution via a simple dispersion method. The structural and physicochemical properties of nanocomposite were investigated in detail. Staphylococcus aureus, Proteus vulgaris, and Bacillus subtilis bacterial strains were employed to study the anti-bacterial activity of GO-Se nanocomposite. The results show that the synthesized nanocomposites have good efficacy as an anti-bacterial agent. UV-vis spectroscopy, FTIR spectroscopy, HRTEM, XPS, and Raman spectroscopy were used to analyze the as-prepared GO and GO-Se nanocomposite.
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  • 文章类型: Journal Article
    Population groups vulnerable to adverse effects of traffic-related air pollution correspond to children, pregnant women and elderly. Despite these effects, literature is limited in terms of studies focusing on these groups and a reason often cited is the limited information on their mobility important for exposure assessment. The current study presents a method for assessing individual-level exposure to traffic-related air pollution by integrating mobility patterns tracked by global positioning system (GPS) devices with dynamics of air pollutant concentrations. The study is based on a pool of 17 pregnant women residing in Hidalgo County, Texas. The traffic-related particulate matter with diameter of less than 2.5 micrometer (PM2.5) emissions and air pollutant concentrations are predicted using MOVES and AERMOD models, respectively. The daily average traffic-related PM2.5 concentration was found to be 0.32 µg/m3, with the highest concentration observed in transit (0.56 µg/m3), followed by indoors (0.29 µg/m3), and outdoor (0.26 µg/m3) microenvironment. The obtained exposure levels exhibited considerable variation between time periods, with higher levels during peak commuting periods, close to the US-Mexico border region and lower levels observed during midday periods. The study also assessed if there is any difference between traffic-related dynamic exposure, based on time-varying mobility patterns, and static exposure, based solely on residential locations, and found a difference of 9%, which could be attributed to the participants\' activity patterns being focused mostly indoors.
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  • 文章类型: Journal Article
    Dispersion stability of nanoparticles in the liquid media is of great importance to the utilization in practice. This study aims to investigate the effects of mechanical dispersion method on the dispersibility of functionalized TiO2 nanoparticles in the transformer oil. Dispersion methods, including stirring, ultrasonic bath, and probe processes, were systematically tested to verify their versatility for preparing stable nanofluid. The test results reveal that the combination of ultrasonic bath process and stirring method has the best dispersion efficiency and the obtained nanofluid possesses the highest AC breakdown strength. Specifically, after aging for 168 h, the size of nanoparticles in the nanofluid prepared by the combination method has no obvious change, while those obtained by the other three paths are increased obviously.
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