enzymatic method

酶法
  • 文章类型: Journal Article
    血红蛋白A1c(HbA1c)在糖尿病管理中起着至关重要的作用。我们旨在评估用于HbA1c测量的新型酶法试剂盒的分析性能。酶法的性能,包括精度,准确度,和线性,进行了评估。此外,常规干扰物的干扰效应,Hb衍生物,Hb变体,和常见药物进行了评估。此外,酶方法之间HbA1c结果的一致性进行了比较,阳离子交换高效液相色谱(HPLC),和免疫测定。内部测定,在测定之间,HbA1c总精密度均低于2%。HbA1c在3.96-20.23%范围内呈良好的线性关系。酶测定产生的结果与外部质量控制样品一致,与目标值的偏差小于±6%。酶法无胆红素干扰,intralipal,维生素C,Hb衍生物,常见的Hb变体,以及解热镇痛药和降血糖药物。与从HPLC方法和免疫测定获得的结果相比,酶促测定的HbA1c结果显示出良好的一致性和准确性。在BS-600M化学分析仪上进行的酶法试剂盒是测量HbA1c的可靠且稳健的方法。它适用于临床化学实验室的常规实践。
    Hemoglobin A1c (HbA1c) plays a crucial role in diabetes management. We aimed to evaluate the analytical performance of a new enzymatic method kit for HbA1c measurement. The performance of the enzymatic method, including precision, accuracy, and linearity, was evaluated. Moreover, the interference effect from conventional interferents, Hb derivatives, Hb variants, and common drugs were assessed. In addition, the agreement of HbA1c results was compared between enzymatic methods, cation-exchange high-performance liquid chromatography (HPLC), and immunoassays. The intra-assay, between-assay, and total precision of HbA1c were all lower than 2%. HbA1c showed good linearity within the range of 3.96-20.23%. The enzymatic assay yielded results consistent with the external quality control samples, with a bias of less than ± 6% from the target values. The enzymatic method showed no interference from bilirubin, intralipid, vitamin C, Hb derivatives, common Hb variants, as well as antipyretic analgesics and hypoglycemic drugs. The HbA1c results of the enzymatic assay showed good agreement and accuracy compared to those obtained from the HPLC method and the immunoassay. The enzymatic method kit performed on the BS-600M chemistry analyzer is a reliable and robust method for measuring HbA1c. It is suitable for routine practice in clinical chemistry laboratories.
    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
    当前的能源危机促使可再生能源和储能材料的开发和利用。在这项研究中,使用乙酰丙酸(LA)和1,4-丁二醇(BDO)通过酶和化学方法合成了新型的乙酰丙酸1,4-丁二醇酯(LBE)。酶法在合成过程中表现出优异的性能,并导致87.33%的LBE产率,而化学法则造成了更多的副产品和更高的能耗。更重要的是,评价所得LBE作为相变材料(PCM)的热性能。差示扫描量热法(DSC)和热重分析(TGA)表明,熔化潜热,热解温度为50.51℃,156.1J/g,和150-160°C,分别。与传统的石蜡相比,制备的PCM具有优越的相变温度,更高的熔化潜热,和更好的热稳定性。添加膨胀石墨(EG)后,热导率可增加到0.34W/m/k。总之,LBE作为低温相变储能材料在储能应用中具有巨大的潜力。
    The current energy crisis has prompted the development and utilization of renewable energy and energy storage material. In this study, levulinic acid (LA) and 1,4-butanediol (BDO) were used to synthesize a novel levulinic acid 1,4-butanediol ester (LBE) by both enzymatic and chemical methods. The enzymatic method exhibited excellent performance during the synthesis process, and resulted in 87.33% of LBE yield, while the chemical method caused more by-products and higher energy consumption. What\'s more, the thermal properties of the obtained LBE as a phase change material (PCM) were evaluated. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that the melting temperature, latent heat of melting, and pyrolysis temperature were 50.51 °C, 156.1 J/g, and 150-160 °C, respectively. Compared with the traditional paraffin, the prepared PCM has a superior phase transition temperature, a higher latent heat of melting, and better thermal stability. The thermal conductivity could be increased to 0.34 W/m/k after adding expanded graphite (EG). In summary, LBE has great potential in the application of energy storage as a low-temperature phase change energy storage material.
    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
    背景:Schwartz方程是最广泛使用的基于血清肌酐(SCr)的公式,用于估算欧洲血统儿童的肾小球滤过率(GFR),但这是否适用于非洲儿童尚不清楚。
    方法:在一项横断面研究中,在金沙萨学区随机招募了513名6至16岁的非洲儿童,刚果民主共和国(DRC)。使用校准的酶法测量SCr。SCr使用为欧洲血统儿童设计的Q值进行归一化,由于非洲儿童没有Q值。在该群体中应用了常用的eGFR方程。
    结果:在该队列中,使用欧洲血统儿童的Q值对SCr进行标准化是有效的。大多数非洲儿童(93.4%)的SCr(SCr/Q)值在欧洲血统儿童的参考区间(0.67-1.33)内正常。床边-Schwartz方程与显着的年龄和性别依赖性相关。然而,FAS-年龄公式显示无性别和年龄依赖性.新的CGiDU25方程没有显示出明显的性别依赖性。最近引入的EKFC和LMR18方程也没有显示出年龄和性别依赖性,尽管eGFR值的分布并不对称。另一方面,FAS身高和Schwartz-Lyon方程显示出明显的性别依赖性,但没有年龄依赖性。
    结论:为欧洲裔儿童设计的SCr参考区间可适用于非洲儿童。在所有研究的方程中,FAS-Age表现最好,最合适,因为不需要进行高度测量。为非洲广泛的Jaffe测量的肌酐建立特定的Q值可以进一步扩大适用性。
    BACKGROUND: The Schwartz equation is the most widely used serum creatinine (SCr)-based formula to estimate the glomerular filtration rate (GFR) in children of European descent, but whether this applies to African children is unclear.
    METHODS: In a cross-sectional study, 513 apparently healthy African children aged 6 to 16 years were randomly recruited in school area of Kinshasa, the Democratic Republic of Congo (DRC). SCr was measured using calibrated enzymatic method. SCr was normalized using Q-values designed for European descent children, due to the absence of Q-values for African children. Commonly used eGFR equations were applied in this population.
    RESULTS: Normalization of SCr using Q-values for European descent children was effective in this cohort. The majority of African children (93.4%) have normalized SCr (SCr/Q) values within the reference interval (0.67-1.33) of children of European descent. The bedside-Schwartz equation was associated with significant age and sex dependency. However, the FAS-Age formula showed no sex and age dependency. The new CKiDU25 equation did not show a significant sex dependency. The recently introduced EKFC and LMR18 equations also showed no age and sex dependency, although the distribution of eGFR-values was not symmetrical. On the other hand, the FAS-Height and the Schwartz-Lyon equations showed significant sex dependency but no age dependency.
    CONCLUSIONS: The reference interval for SCr designed for European descent children can be applied to African children. Of all the equations studied, FAS-Age performed best and is most suitable because no height measurements are required. Establishment of specific Q-values for the widespread Jaffe-measured creatinine in Africa can further broaden applicability.
    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
    血清肌酐(SCr),主要通过Jaffe或酶法测定,是评估肾功能的核心指标。这两种方法之间的偏差可能会影响急性肾损伤(AKI)和慢性肾脏病(CKD)的诊断和分期。
    在埃森大学医院(埃森,德国)在2020-2022年间进行了回顾性评估。使用具有95%一致性极限(LoA)的Bland-Altman图评估Jaffe和酶促SCr(eSCr)方法之间的差异。我们使用2009年慢性肾脏病流行病学合作方程根据肾脏病:改善全球结果指南确定估计的肾小球滤过率(eGFR)。
    评价了总共41.144次平行SCr测量。平均而言,JaffeSCr比eSCr高0.07mg/dl(LoA-0.12;0.25mg/dl)。在19%的所有病例中,当比较两种SCr方法之间的eGFR时,CKD阶段不同。其中98%导致JaffeSCr确定的更严重的CKD阶段。在所有病例中,1.6%的JaffeSCr高于eSCr≥0.3mg/dl。
    本研究表明,SCr测量方法可能会影响AKI和CKD的诊断和分期。在日常临床实践中解释肾功能测量时,必须考虑到这一点。而且在计划和比较肾脏疾病的研究时也是如此。因此,应该使用一种方法进行SCr测量,优选使用酶法。
    UNASSIGNED: Serum creatinine (SCr), mainly determined by the Jaffe or an enzymatic method, is the central marker to assess kidney function. Deviations between these two methods may affect the diagnosis and staging of acute kidney injury (AKI) and chronic kidney disease (CKD).
    UNASSIGNED: The results of the first parallel SCr measurement (Jaffe and enzymatic method) of adult in- and outpatients in the same serum sample at the University Hospital Essen (Essen, Germany) between 2020-2022 were retrospectively evaluated. A Bland-Altman plot with 95% limits of agreement (LoAs) was used to assess the difference between the Jaffe and the enzymatic SCr (eSCr) method. We used the 2009 Chronic Kidney Disease Epidemiology Collaboration equation for determination of estimated glomerular filtration rate (eGFR) according to the Kidney Disease: Improving Global Outcomes guidelines.
    UNASSIGNED: A total of 41 144 parallel SCr measurements were evaluated. On average, Jaffe SCr was 0.07 mg/dl higher than eSCr (LoA -0.12; 0.25 mg/dl). In 19% of all cases there was a different CKD stage when comparing eGFR between both SCr methods, of which 98% resulted in a more severe CKD stage determined with Jaffe SCr. In 1.6% of all cases Jaffe SCr was ≥0.3 mg/dl higher than eSCr.
    UNASSIGNED: The present study showed that methods of SCr measurement may affect both the diagnosis and staging of AKI and CKD. This must be taken into account when interpreting measurements of renal function in everyday clinical practice, but also when planning and comparing studies on renal diseases. One should therefore stay with one method for SCr measurement, preferably with the enzymatic method.
    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
    正确测量血液和尿肌酐水平对于识别和追踪慢性肾病(CKD)是必要的。
    本研究的目的是比较Jaffe和酶方法测量血清和尿液中的肌酐,为了确定它们之间是否有任何统计上的显著差异,以及它们是否反映在肌酐清除率计算和估计的肾小球滤过率(eGFR)上。
    使用Jaffe方法在DimensionRxL生化分析仪上对24至69岁的患者组(N=60;女性=34,男性=26)进行血清和尿液中的肌酐测定,和酶法在综合生化和免疫化学分析仪Architectci8200上,并将获得的水平用于肌酐清除率计算和eGFR。
    这些方法相关性很好,测量血清肌酐(r1=0.990)和测量尿肌酐(r2=0.974)。它们之间没有统计学上的显著差异(p=0.57)。使用不同的方法测量肌酐显示计算的清除率没有统计学上的显着差异(p=0.93),它们显著相关(r=0.9722)。eGFR,使用MDRD和CKD-EPI公式,没有统计学上的显著差异,不管使用的方法。
    除了使用的方法之间的显著相关性之外,使用Jaffe和酶法的结果在测量血清肌酐水平方面没有显着差异,或肌酐清除率和肾小球滤过率。
    UNASSIGNED: Correct measuring of blood and urine creatinine level is necessary for identification and tracking of chronic kidney disease (CKD).
    UNASSIGNED: The aim of this study is a comparison of Jaffe and enzymatic methods for measuring creatinine in serum and in urine, in order to determine whether there are any statistical significant differences between them, and whether they are reflected on creatinine clearance calculation and estimated glomerular filtration rate (eGFR).
    UNASSIGNED: Creatinine in serum and urine was measured for the group of patients (N=60; female=34, male=26) from 24 to 69 years of age by using Jaffe\'s method on Dimension RxL biochemical analyzer, and enzymatic method on integrated biochemical and immunochemical analyzer Architect ci8200, and obtained levels are used for creatinine clearance calculation and eGFR.
    UNASSIGNED: The methods correlate well, both in measuring serum creatinine (r 1 = 0.990) and in measuring urine creatinine (r 2 =0.974). There are no statistically significant differences between them (p=0.57). Measuring creatinine using different methods showed no statistically significant differences in the calculated clearances (p=0.93), they significantly correlate (r=0.9722). eGFR, using the MDRD and CKD-EPI formulas, were not statistically significantly different, regardless of the used method.
    UNASSIGNED: Apart from significant correlations between the used methods, the results of using the Jaffe and enzymatic methods showed no significant differences at measuring serum creatinine level, or creatinine clearance and glomerular filtration rate.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Case Reports
    背景:肌酐浓度升高通常表明急性肾损伤,在这种情况下考虑肾活检。然而,假性高肌酐血症是肌酐浓度升高的潜在原因,应避免侵入性干预。
    方法:一名54岁女性接受了降主动脉夹层手术。术后9天,她的肌酐浓度从1毫克/分升增加到5.78毫克/分升(正常范围,0.47-0.7mg/dl)。没有氮质血症和高钾血症,体格检查结果不明显。胱抑素C浓度为1.56mg/l(正常范围,0.56-0.8mg/l),怀疑是假性高肌酐血症。用不同试剂的测试显示肌酸酐浓度为0.84mg/dl。免疫球蛋白(Ig)G显著升高,肌酐和IgG平行波动,提示了假性高肌酐血症的病因.IgG4也升高至844mg/dl。免疫抑制类固醇治疗可有效降低IgG浓度并解决假性高肌酐血症。
    结论:在肌酐浓度升高并存在异常蛋白的情况下,应考虑假性高肌酐血症。我们报告了一例罕见的由多克隆IgG引起的假性高肌酐血症。
    Elevated creatinine concentrations often indicate acute renal injury and renal biopsies are considered in this situation. However,pseudohypercreatininemia is potential cause of elevated creatinine concentrations, and invasive interventions should be avoided.
    A 54-year-old woman underwent surgery for descending aortic dissection.Nine days postoperatively, her creatinine concentration increased from 1 mg/dl to 5.78 mg/dl (normal range, 0.47-0.7 mg/dl). Azotemia and hyperkalemia were absent and physical examination findings were unremarkable. Cystatin C concentration was 1.56 mg/l (normal range, 0.56-0.8 mg/l) and pseudohypercreatininemia was suspected. Testing with different reagents showed a creatinine concentration of 0.84 mg/dl. Immunoglobulin (Ig)G was markedly elevated, and creatinine and IgG fluctuated in parallel, suggesting the cause of the pseudohypercreatininemia. IgG4 was also elevated at 844 mg/dl. Immunosuppressive steroid therapy effectively decreased the IgG concentration and resolved the pseudohypercreatininemia.
    In cases of elevated creatinine concentration with the presence of abnormal proteins, pseudohypercreatininemia should be considered. We report a rare case of pseudohypercreatininemia caused by polyclonal IgG.
    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
    皮克林乳液凝胶代表了一类新型的无毒和生物相容性乳液,在制药和食品添加剂领域提供广泛的应用。这项研究描述了利用天然和酰胺化果胶样品合成Pickering乳液凝胶。苯丙氨酸酰胺化果胶(AP)通过超低温酶法获得,而对照组(LP)坚持相同的程序,没有木瓜蛋白酶催化。实验结果表明,与果胶乳液样品(PE和LP)相比,APPickering乳液凝胶表现出优异的稳定性。来自5%酰胺化果胶(5AP)的Pickering乳液凝胶在整个14天乳液稳定性评估中保持稳定性。此外,在体外消化模拟中评估了所有乳液样品递送和维持姜黄素的能力.流变性能和油滴大小结果表明,5APPickering乳液凝胶表现出最佳的乳膏指数和乳液稳定性,有效地抑制乳液内过早的水油分层和增加姜黄素的生物可及性。在体外消化模拟中,5APPickering乳液凝胶显示出最高的姜黄素生物可及性,测量为17.96%。
    Pickering emulsion gels represent a novel class of non-toxic and biocompatible emulsions, offering extensive applications in the pharmaceutical and food additive sectors. This study delineates the synthesis of Pickering emulsion gels utilizing native and amidated pectin samples. Phenylalanine amidated pectin (AP) was procured via an ultra-low temperature enzyme method, while the control group (LP) adhered to an identical procedure without papain catalysis. Experimental outcomes revealed that the AP Pickering emulsion gel manifested superior stability compared to pectin emulsion samples (PE and LP). The Pickering emulsion gel from 5 % amidated pectin (5AP) retained stability throughout a 14-day emulsion stability assessment. Furthermore, all emulsion samples were evaluated for their capacity to deliver and sustain curcumin within an in vitro digestion simulation. Rheological properties and oil droplet size results indicated that the 5AP Pickering emulsion gel exhibited optimal cream index and emulsion stability, effectively inhibiting premature water-oil stratification within the emulsion and augmenting curcumin bioaccessibility. Within the in vitro digestion simulation, the 5AP Pickering emulsion gel demonstrated the highest curcumin bioaccessibility, measured at 17.96 %.
    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
    来自围产期组织的间充质基质/干细胞(MSCs)由于其优越的特性,已成为临床应用不可或缺的来源。易于访问和最小的道德问题。从不同的胎盘(PL)和脐带(UC)隔室分离的MSC显示出基于干细胞的治疗的巨大潜力。然而,由于组织起源和分化潜能的差异,它们的生物活性可能会有所不同。这篇综述概述了来自围产期组织不同区室的MSCs,它们的特点和目前的隔离方法。还讨论了影响MSC的产率和纯度的因素,因为它们对于确保再生医学和组织工程的一致和无限供应是重要的。
    Mesenchymal stromal/stem cells (MSCs) derived from perinatal tissues have become indispensable sources for clinical applications due to their superior properties, ease of accessibility and minimal ethical concerns. MSCs isolated from different placenta (PL) and umbilical cord (UC) compartments exhibit great potential for stem cell-based therapies. However, their biological activities could vary due to tissue origins and differences in differentiation potentials. This review provides an overview of MSCs derived from various compartments of perinatal tissues, their characteristics and current isolation methods. Factors affecting the yield and purity of MSCs are also discussed as they are important to ensure consistent and unlimited supply for regenerative medicine and tissue engineering.
    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
    原位酶促生成双金属纳米颗粒,主要是Au/Pt,克服了缺点(连续吸光度漂移,适度的LOQ,和长时间反应)当单独产生AuNP时观察到。在这项研究中,Au/Pt纳米粒子已通过EDS表征,XPS,以酪胺氧化酶(TAO)为模型,以酶法测定酪胺和HRTEM图像。在实验条件下,Au/PtNP在580nm处显示出最大吸收,这可能与酪胺的浓度在1.0×10-6M至2.5×10-4M范围内有关,RSD为3.4%(n=5,使用5×10-6M酪胺)。Au/Pt系统可实现低LOQ(1.0×10-6M),吸光度漂移的高度降低,和反应时间的显著缩短(即,对于[酪胺]=1×10-4M),从30到2分钟;此外,也获得了更好的选择性。该方法已应用于腌制干酪中酪胺的测定,与参考方法(HRP:TMB)相比,没有显着差异。Pt(II)的作用似乎涉及先前将Au(III)还原为Au(I)以及从该氧化态产生NP。最后,提出了产生NP的三步(成核-生长-聚集)动力学模型;这使我们能够获得一个数学方程,该方程解释了实验观察到的吸光度随时间的变化。
    In situ enzymatic generation of bimetallic nanoparticles, mainly Au/Pt, overcomes the drawbacks (continuous absorbance drift, modest LOQ, and long-time reaction) observed when AuNP alone are produced. In this study, Au/Pt nanoparticles have been characterized by EDS, XPS, and HRTEM images using the enzymatic determination of tyramine with tyramine oxidase (TAO) as a model. Under experimental conditions, the Au/Pt NPs show an absorption maximum at 580 nm which can be related to the concentration of tyramine in the range 1.0 × 10-6M to 2.5 × 10-4M with a RSD of 3.4% (n = 5, using 5 × 10-6M tyramine). The Au/Pt system enables low LOQ (1.0 × 10-6 M), high reduction of the absorbance drift, and a significant shortening of the reaction time (i.e., from 30 to 2 min for a [tyramine] = 1 × 10-4M); additionally, a better selectivity is also obtained. The method has been applied to tyramine determination in cured cheese and no significant differences were obtained compared to a reference method (HRP:TMB). The effect of Pt(II) seems to involve the previous reduction of Au(III) to Au(I) and NP generation from this oxidation state. Finally, a three-step (nucleation-growth-aggregation) kinetic model for the generation of NPs is proposed; this has enabled us to obtain a mathematical equation which explains the experimentally observed variation of the absorbance with time.
    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
    在本文中,以α-丙氨酸和β-丙氨酸为改性剂,通过酶法制备α-丙氨酸酰胺化果胶(α-AP)和β-丙氨酸酰胺化果胶(β-AP)。研究了丙氨酸及其异构体对果胶酰胺化程度和理化性质的影响。傅里叶变换红外光谱,质子核磁共振分析,X射线光电子能谱和元素分析表明,α-C和β-C的氨基可以与果胶的羧基胺化,形成相应的胺化果胶。α-AP和β-AP的丙氨酸接枝率分别为21.99%和18.92%,分别。结果表明,由于氨基酸侧链的影响,β-AP的动态粘度明显高于α-AP。然而,由于α-AP的丙氨酸接枝率较高,α-AP制备的水凝胶强度高于β-AP,它还具有最高的弹性模量和溶胀能力。此外,果胶,作为一种基于碳水化合物的脂肪替代品,已广泛用于食品领域,以模拟脂肪的光滑细腻的味道。与高甲氧基果胶(HMP)和β-AP相比,α-AP在复合体系中具有较好的胶体稳定性和较小的水凝胶颗粒。研究结果为酰胺化果胶在低脂食品中的应用提供了参考。
    In this paper, α-alanine and β-alanine were used as modifiers to prepare α-alanine amidated pectin (α-AP) and β-alanine amidated pectin (β-AP) through enzymatic method. The effects of alanine and its isomer on the amidation degree and physicochemical properties of pectin were studied. Fourier transform infrared spectrum, proton nuclear magnetic resonance analysis, X-ray photoelectron spectrum and elemental analysis indicated that the amino groups from α-C and β-C could be aminated with the carboxyl group of pectin to form the corresponding aminated pectin. The alanine grafting ratio of α-AP and β-AP were 21.99% and 18.92%, respectively. The results showed that the dynamic viscosity of β-AP was significantly higher than that of α-AP due to the influence of amino acid side chain. However, due to the higher alanine grafting ratio of α-AP, the strength of hydrogel prepared by α-AP was higher than that of β-AP, and it also has the highest elastic modulus and swelling capacity. In addition, pectin, as a carbohydrate-based fat substitute, has been widely used in the field of food to simulate the smooth and delicate taste of fat. Compared with High methoxy pectin (HMP) and β-AP, α-AP had better colloid stability and smaller hydrogel particles in the composite system. The results provide references for the application of amidated pectin in low-fat food.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号