separation

分离
  • 文章类型: Journal Article
    作为一种新型的多孔结晶复合材料,MOF-COF在金属分离方面显示出巨大的优势。在这里,CoMOF-COF被设计用于高选择性分离痕量Pb2+离子。设计的CoMOF-COF具有高密度的氮-氧官能团,可以选择性地分离金属离子。设计的CoMOF-COF材料与金属Pb2+离子之间有很强的亲和力,这可以归因于有序的异质多孔结构和大量的含氮和氧官能团。该复合材料对Pb2+离子具有较高的吸附选择性,吸附容量为33mgg-1,具有较高的化学稳定性。基于这种固相萃取材料,建立了一种高灵敏度的Pb2+离子检测方法,检出限为37.3ngL-1,精密度为1.9%。线性检测范围为0.2-10ngmL-1,实现了实际水样中Pb2+离子的检测。通过这项研究,证明了所设计的CoMOF-COF材料与金属Pb2+离子之间的强亲和力可以归因于软酸碱理论和硬酸碱理论,揭示了这种材料的多孔异质结构与金属分离之间的结构-活性关系,为其他环境污染物的分离提供了高度选择性的分离材料。
    As a new type of porous crystalline composite material, MOF-COF has shown great advantages in metal separation. Herein, a CoMOF-COF was designed for highly selective separation of trace Pb2+ ions. The designed CoMOF-COF has a high density of nitrogen-oxygen functional groups and can selectively separate metal ions. There is a strong affinity between the designed CoMOF-COF material and metal Pb2+ ions, which can be attributed to the ordered heterogeneous porous structure and large amounts of nitrogen-and oxygen-containing functional groups. The composite showed high adsorption selectivity for Pb2+ ions and had adsorption capacity of 33 mg g-1, with high chemical stability. Based on this solid phase extraction material, a high sensitivity detection method for Pb2+ ions was established, which has the detection limit of 37.3 ng L-1, precision of 1.9 %. Linear detection range is 0.2-10 ng mL-1, and the detection of Pb2+ ions in actual water samples was realized. Through this study, it is proved that the strong affinity between the designed CoMOF-COF materials and metal Pb2+ ions can be attributed to the soft and hard acid-base theory, which reveals the structure-activity relationship between the porous heterostructure of such materials and metal separation, providing a highly selective separation material for the separation of other environmental pollutants.
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  • 文章类型: Journal Article
    这项研究的重点是使用一种新的基于电的膜方法(称为过滤膜电渗析(EDFM))对胰岛素样生长因子I(IGF-I)和转化生长因子-β2(TGF-β2)进行分馏。在EDFM之前,测试了不同的预处理,在EDFM期间使用四种pH条件(4.25、3.85、3.45和3.05)。已证明,用去离子水对脱脂初乳进行1:1稀释以降低矿物质含量,然后用UF预浓缩GFs是必要的,并允许这些化合物在EDFM过程中迁移到回收室。MS分析证实了迁移,数量少,在EDFM期间,只有α-乳白蛋白(α-la)和β-乳球蛋白(β-lg)从血清型到恢复室。因此,在pH值为3.05时,回收室中GFs与总蛋白的比例比饲料血清型溶液高60倍,最佳pH有利于IGF-I和TGF-β2的迁移。最后,在酸乳清上测试了这些最佳条件,以证明所提出的工艺对干酪工业主要副产品之一的可行性;回收室中GFs与总蛋白的比率比饲料酸乳清溶液高2.7倍,只有α-la迁移。首次提出了结合超滤和电渗析技术对不同乳制品溶液进行GF富集的技术。
    This study is focused on fractionation of insulin-like growth factor I (IGF-I) and transforming growth factor-β2 (TGF-β2) using a new electro-based membrane process calledelectrodialysis with filtration membranes (EDFM). Before EDFM, different pretreatments were tested, and four pH conditions (4.25, 3.85, 3.45, and 3.05) were used during EDFM. It was demonstrated that a 1:1 dilution of defatted colostrum with deionized water to decrease mineral content followed by the preconcentration of GFs by UF is necessary and allow for these compounds to migrate to the recovery compartment during EDFM. MS analyses confirmed the migration, in low quantity, of only α-lactalbumin (α-la) and β-lactoglobulin (β-lg) from serocolostrum to the recovery compartment during EDFM. Consequently, the ratio of GFs to total protein in recovery compartment compared to that of feed serocolostrum solution was 60× higher at pH value 3.05, the optimal pH favoring the migration of IGF-I and TGF-β2. Finally, these optimal conditions were tested on acid whey to also demonstrate the feasibility of the proposed process on one of the main by-products of the cheese industry; the ratio of GFs to total protein was 2.7× higher in recovery compartment than in feed acid whey solution, and only α-la migrated. The technology of GF enrichment for different dairy solutions by combining ultrafiltration and electrodialysis technologies was proposed for the first time.
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  • 文章类型: Journal Article
    要分析婚姻结局,离婚或分居,以及它与人口统计的联系,社会经济,诊断2年后乳腺癌(BC)幸存者的临床病理因素。
    我们对参与AMAZONAIII(GBECAM0115)研究的年龄≥18岁诊断为侵袭性BC的女性进行了基线和随访第1年和第2年的婚姻状况回顾性分析。BC诊断发生在2016年1月至2018年3月之间,在巴西的23个机构中。
    在参加AMAZONAIII的2974名女性中,599人在基线时已婚或生活在普通法下。在随访2年时,35例(5.8%)患者发生了离婚或分居。在多变量分析中,公共健康保险覆盖率与较高的婚姻状况变化风险相关(8.25%与2.79%,RR3.09,95%CI1.39-7.03,p=0.007)。做了乳房切除术的女性,腺样体切除术或保留皮肤的乳房切除术与离婚或分居的风险较高(8.1%vs.4.49%,RR1.97,95CI1.04-3.72,p=0.0366)比接受保乳手术的患者高。
    公共卫生系统覆盖的妇女和接受乳房切除术的妇女,乳腺腺切除术或保留皮肤的乳房切除术与较高的离婚或分居风险相关。这一证据进一步支持了长期婚姻稳定与社会经济条件和压力源之间复杂的相互作用有关的观点。如BC的诊断和治疗。临床试验注册:NCT02663973。
    UNASSIGNED: To analyze marital outcomes, divorce or separation, and its association with demographic, socioeconomic, and clinicopathological factors among breast cancer (BC) survivors after 2-years of diagnosis.
    UNASSIGNED: We performed a retrospective analysis of marital status at baseline and at years 1 and 2 of follow-up of women aged ≥ 18 years diagnosed with invasive BC participating in the AMAZONA III (GBECAM0115) study. The BC diagnosis occurred between January 2016 and March 2018 at 23 institutions in Brazil.
    UNASSIGNED: Of the 2974 women enrolled in AMAZONA III, 599 were married or living under common law at baseline. Divorce or separation occurred in 35 (5.8%) patients at 2 years of follow-up. In the multivariate analysis, public health insurance coverage was associated with a higher risk of marital status change (8.25% vs. 2.79%, RR 3.09, 95% CI 1.39 - 7.03, p = 0.007). Women who underwent mastectomy, adenomastectomy or skin-sparing mastectomy were associated with a higher risk of divorce or separation (8.1% vs. 4.49%, RR 1.97, 95 CI 1.04 - 3.72, p = 0.0366) than those who underwent breast-conserving surgery.
    UNASSIGNED: Women covered by the public health system and those who underwent mastectomy, adenomastectomy or skin-sparing mastectomy were associated with a higher risk of divorce or separation. This evidence further supports the idea that long-term marital stability is associated with a complex interplay between socioeconomic conditions and stressors, such as BC diagnosis and treatment. ClinicalTrials Registration: NCT02663973.
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  • 文章类型: Editorial
    暂无摘要。
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  • 文章类型: Journal Article
    已知微塑料在水生环境中无处不在。天然水中微塑料的定量是分析化学的一个重要问题,评估水质和水居民和消费者的潜在风险是需要的解决方案。分离方法在正确定量天然水中的微塑料中起着关键作用。在本研究中,首次证明了逆流色谱法在使用水-油系统的旋转盘绕柱(RCC)中从水样中连续流分离和预浓缩微塑料的适用性。研究了色谱柱转速和流动相(水)流速对RCC中固定(油)相保留的影响。确定了10种植物油和2种合成油的保留参数。蓖麻,橄榄,油菜籽,大豆,亚麻籽,芝麻,发现向日葵油适用于使用RCC从水样中分离微塑料。以不同尺寸(40-63、63-100和100-250μm)的聚乙烯微粒为例,显示出微塑料从水相中到蓖麻油和菜籽油中的高回收率(约100%)。该方法已被证明可有效地从模拟的淡水和海水中分离微塑料。它不仅可以用于量化天然水中的微塑料,而且可以用于净化含有微塑料的废水。
    Microplastics is known to be ubiquitous in aquatic environment. Quantification of microplastics in natural waters is an important problem of analytical chemistry, the solution of which is needed for the assessment of water quality and potential risks for water inhabitants and consumers. Separation methods play a key role in the correct quantification of microplastics in natural waters. In the present study the applicability of countercurrent chromatography to the continuous-flow separation and preconcentration of microplastics from water samples in rotating coiled column (RCC) using water-oil systems has been demonstrated for the first time. The effect of column rotation speed and mobile phase (water) flow rate on the retention of the stationary (oil) phase in RCC is studied. The retention parameters of 10 vegetable and 2 synthetic oils are determined. Castor, olive, rapeseed, soybean, linseed, sesame, and sunflower oils are found to be applicable to the separation of microplastics from water samples using RCC. Taking as example polyethylene microparticles of different size (40-63, 63-100, and 100-250 μm), the high recovery of microplastics (about 100 %) from aqueous phase into castor and rapeseed oils is shown. The method has been proven to be efficient for the separation of microplastics from simulated fresh and sea natural waters. It may be perspective not only for the quantification of microplastics in natural waters but as well as for the purification of wastewaters containing microplastics.
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  • 文章类型: Journal Article
    通过将超临界流体色谱(SFC)与中压反相液相色谱(MP-RPLC)相结合的综合两步正交纯化工艺,成功地以>95%的纯度大量(〜30g)纯化了大环肽A。使用MP-RPLC分级分离粗肽A,去除不需要的三氟乙酸(TFA)源自肽A裂解树脂,并将肽A转化为乙酸铵盐形式,在SFC最终纯化之前。在WatersBEH2-乙基吡啶色谱柱上开发了在CO2中含有乙酸铵和水的甲醇/乙腈共溶剂。将开发的SFC方法容易地放大到5cm直径的柱上,以处理多克量的MP-RPLC级分,以达到>95%的纯度,产量/生产率为0.96g/h。已证明SFC与MP-RPLC的掺入在其他大规模多肽纯化中具有更广泛的应用。
    A macrocyclic peptide A was successfully purified in large quantities (∼30 g) in >95 % purity by an integrated two-step orthogonal purification process combining supercritical fluid chromatography (SFC) with medium-pressure reverse-phase liquid chromatography (MP-RPLC). MP-RPLC was used to fractionate the crude peptide A, remove unwanted trifluoroacetic acid (TFA) originating from the peptide A cleavage off the resin, and convert the peptide A into ammonium acetate salt form, prior to the final purification by SFC. A co-solvent of methanol/acetonitrile containing ammonium acetate and water in CO2 was developed on a Waters BEH 2-Ethylpyridine column. The developed SFC method was readily scaled up onto a 5 cm diameter column to process multi-gram quantities of the MP-RPLC fraction to reach > 95 % purity with a throughput/productivity of 0.96 g/h. The incorporation of SFC with MP-RPLC has been demonstrated to have a broader application in other large-scale polypeptide purifications.
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  • 文章类型: Journal Article
    背景:在临床研究的二元分类中,案例到类的不平衡分布以及二元因变量和独立变量子集之间的极端关联水平可能会产生重大的分类问题。这些关键问题,即阶级不平衡和完全分离,导致临床研究中分类不准确和结果有偏差。
    方法:为了处理类不平衡和完成分离问题,我们建议使用模糊逻辑回归框架进行二元分类。模糊逻辑回归结合了系数的三角模糊数的组合,输入,并输出并产生清晰的分类结果。由于模糊逻辑对不平衡和分离问题的更好处理,模糊逻辑回归框架显示出强大的分类性能。因此,提高了分类精度,降低临床研究患者的错误分类条件和偏颇见解的风险。
    结果:在具有临床数据集的十二个二元分类问题上评估了模糊逻辑回归模型的性能。该模型具有一贯的高灵敏度,特异性,F1,精度,和所有临床数据集的Mathew相关系数得分。没有证据表明数据集中存在的不平衡或分离会产生影响。此外,我们将模糊逻辑回归分类性能与经典逻辑回归的两个版本和文献中的六个不同的基准来源进行比较。这六个来源总共提供了十种不同的拟议方法,并且通过计算每种方法的相同分类性能分数集来进行比较。不平衡或分离会影响十分之七的方法。其余三个在各自的临床研究中产生更好的分类性能。然而,这些都优于模糊逻辑回归框架。
    结论:模糊逻辑回归显示了对不平衡和分离的强大表现,提供准确的预测,因此,在临床研究中对患者进行分类的信息见解。
    BACKGROUND: In binary classification for clinical studies, an imbalanced distribution of cases to classes and an extreme association level between the binary dependent variable and a subset of independent variables can create significant classification problems. These crucial issues, namely class imbalance and complete separation, lead to classification inaccuracy and biased results in clinical studies.
    METHODS: To deal with class imbalance and complete separation problems, we propose using a fuzzy logistic regression framework for binary classification. Fuzzy logistic regression incorporates combinations of triangular fuzzy numbers for the coefficients, inputs, and outputs and produces crisp classification results. The fuzzy logistic regression framework shows strong classification performance due to fuzzy logic\'s better handling of imbalance and separation issues. Hence, classification accuracy is improved, mitigating the risk of misclassified conditions and biased insights for clinical study patients.
    RESULTS: The performance of the fuzzy logistic regression model is assessed on twelve binary classification problems with clinical datasets. The model has consistently high sensitivity, specificity, F1, precision, and Mathew\'s correlation coefficient scores across all clinical datasets. There is no evidence of impact from the imbalance or separation that exists in the datasets. Furthermore, we compare the fuzzy logistic regression classification performance against two versions of classical logistic regression and six different benchmark sources in the literature. These six sources provide a total of ten different proposed methodologies, and the comparison occurs by calculating the same set of classification performance scores for each method. Either imbalance or separation impacts seven out of ten methodologies. The remaining three produce better classification performance in their respective clinical studies. However, these are all outperformed by the fuzzy logistic regression framework.
    CONCLUSIONS: Fuzzy logistic regression showcases strong performance against imbalance and separation, providing accurate predictions and, hence, informative insights for classifying patients in clinical studies.
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  • 文章类型: Journal Article
    为了提高二氧化硅纳米纤维(SiO2NFs)对铯离子(Cs+)的选择性分离性能,克服普鲁士蓝纳米颗粒(PBNPs)的缺陷,制备PB/SiO2-NH2NFs以从水中除去Cs。其中,3-氨基丙基三乙氧基硅烷(APTES)与SiO2进行烷基化反应,形成了致密的Si-O-Si网络结构,修饰了SiO2NF的表面。同时,APTES中的氨基官能团与Fe3+结合,然后与Fe2+反应形成PBNP,牢固地固定在氨基化的SiO2NFs表面上。在我们的实验中,PB/SiO2-NH2NFs的最大吸附量为111.38mg/g,比SiO2NFs高31.5mg/g。同时,在第五个周期之后,PB/SiO2-NH2NFs吸附剂对Cs的去除率为75.36%±3.69%。此外,结合Freundlich模型和准两阶段拟合模型,分别。进一步的机理分析表明,PB/SiO2-NH2NFs与Cs+的键合主要是离子交换的协同作用,静电吸附和膜分离。
    To improve the selective separation performance of silica nanofibers (SiO2 NFs) for cesium ions (Cs+) and overcome the defects of Prussian blue nanoparticles (PB NPs), PB/SiO2-NH2 NFs were prepared to remove Cs+ from water. Among them, 3-aminopropyltriethoxysilane (APTES) underwent an alkylation reaction with SiO2, resulting in the formation of a dense Si-O-Si network structure that decorated the surface of SiO2 NFs. Meanwhile, the amino functional groups in APTES combined with Fe3+ and then reacted with Fe2+ to form PB NPs, which anchored firmly on the aminoated SiO2 NFs surface. In our experiment, the maximum adsorption capacity of PB/SiO2-NH2 NFs was 111.38 mg/g, which was 31.5 mg/g higher than that of SiO2 NFs. At the same time, after the fifth cycle, the removal rate of Cs+ by PB/SiO2-NH2 NFs adsorbent was 75.36% ± 3.69%. In addition, the adsorption isotherms and adsorption kinetics of PB/SiO2-NH2 NFs were combined with the Freundlich model and the quasi-two-stage fitting model, respectively. Further mechanism analysis showed that the bond between PB/SiO2-NH2 NFs and Cs+ was mainly a synergistic action of ion exchange, electrostatic adsorption and membrane separation.
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  • 文章类型: Journal Article
    半参数概率指数模型允许比较两组观测值,在调整协变量的同时,从而在广义成对比较(GPC)的框架内很好地拟合。与此设置中的大多数回归方法一样,由于不满足渐近正态假设,有限的数据量导致无效的推断。此外,当考虑小样本时,可能会出现分离问题。在这篇文章中,我们证明了概率指数模型的参数可以使用广义估计方程来估计,对于存在的调整,导致三明治方差-协方差矩阵的估计器具有改进的有限样本属性,并且可以处理由于分离引起的偏差。这样,通过广泛的模拟研究表明,可以进行适当的推断。概率指数和其他GPC统计数据之间的已知关系也可以提供有效的推断,例如,净治疗效益或成功几率。
    Semiparametric probabilistic index models allow for the comparison of two groups of observations, whilst adjusting for covariates, thereby fitting nicely within the framework of generalized pairwise comparisons (GPC). As with most regression approaches in this setting, the limited amount of data results in invalid inference as the asymptotic normality assumption is not met. In addition, separation issues might arise when considering small samples. In this article, we show that the parameters of the probabilistic index model can be estimated using generalized estimating equations, for which adjustments exist that lead to estimators of the sandwich variance-covariance matrix with improved finite sample properties and that can deal with bias due to separation. In this way, appropriate inference can be performed as is shown through extensive simulation studies. The known relationships between the probabilistic index and other GPC statistics allow to also provide valid inference for example, the net treatment benefit or the success odds.
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  • 文章类型: Journal Article
    现代科学在重矿物应用方面的最新进展,工程,几十年来,技术和冶金工业特别是核能和电力工业的需求显着增加。这是重矿物产品的关键性和商业化的原因,也需要工业对其的高需求。重质矿物的回收,例如:来自其矿床的Zr和Ti伴生矿物依赖于来自复杂矿物的过渡金属和难熔金属的提取冶金。根据矿物浓缩和金属提取的有效性和效率,在他们的恢复过程中遇到了一些挑战,特别是在它们与相关的矿物杂质或脉石的分离中。然而,这篇综述的重点是研究磁性和静电物理处理技术及其在重矿物选矿和回收中的应用。因此,这将是,作为减少工艺步骤和提取复杂性的工具,涉及到溶解和湿法冶金过程的下游措施的矿物。
    Recent advancements in the applications of heavy minerals by modern science, engineering, technological and metallurgical industries especially in the demand by nuclear and power industries have significantly increased over the decades. This is the reason for the criticality and commerciality of products of heavy minerals and also necessitated their high demand by industries. The recovery of heavy minerals, such as: Zr and Ti associated minerals from their deposits is dependent on extractive metallurgy of transition and refractory metals from complex minerals. Based on the effectiveness and efficiency of mineral concentration as well as metal extraction, several challenges have been encountered in their recovery process, especially in their separation from associated mineral impurities or gangue. This review is however focused on investigating magnetic and electrostatic physical processing techniques and their applications in the beneficiation and recovery of heavy minerals. This will therefore, serve as a tool in reducing process steps and extraction complexity involved in downstream measures of dissolution and hydrometallurgical processes of the minerals.
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