Research Progress in Detection of Explosives by Chemical Colorimetric Method

This article reviews the current application status and research progress of colorimetric detection methods based on chemical colorimetry in the detection of explosives.It mainly introduced colorimetric sensors,colorimetric sensor arrays,and chemical colorimetric sensors based on novel material substrates.The application prospect of chemical colorimetric method in the field of explosives detection was prospected.

Detection of Atrazine Residue in Food Samples by a Monoclonal Antibody-based Enzyme-linked Immunosorbent Assay

Atrazine（AT,2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine）has been detected in ground water in several areas of the United States for many years,as well as in China,wherein the growth rate of its gross

Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay

A selective and sensitive competitive enzyme-linked immunosorbent assay(ELISA) method was developed and validated for the quantification of erlotinib in 50 mL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity(6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib.

Seropositivity rates of water channel protein 4 antibodies compared between a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay in neuromyelitis optica patients

A total of 66 samples （from 27 cases with neuromyelitis optica, 26 cases with multiple sclerosis, aa 13 cases with optic neuritis） were tested for aquaporin-4 antibody by a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay. The sensitivities and specificities of the two assays were similar. We further analyzed an additional 68 patients and 93 healthy controls using the enzyme-linked immunosorbent assay. A Kappa test showed good consistency between the two methods in terms of detection of anti-aquaporin-4 antibody in the se of neuromyelitis optica patients. No significant correlations were identified with onset age or disea duration, suggesting that aquaporin-4 antibody is a good marker for neuromyelitis optica. The enzyme-linked immunosorbent assay can be used for quantifying aquaporin-4 antibody concentrations and may be useful to dynamically monitor changes in the levels of aquaporin-4 antibody during disease duration.

Development of a competitive enzyme-linked immunosorbent assay for therapeutic drug monitoring of afatinib

Afatinib is an oral tyrosine kinase inhibitor(TKI) approved for treating advanced non-small cell lung cancer. It is necessary to develop a simple quantification method for TKIs in order to facilitate therapeutic drug monitoring(TDM) in clinical settings. This study sought to develop a simple and sensitive competitive enzyme-linked immunosorbent assay(ELISA) to quantify afatinib in plasma for routine pharmacokinetic applications. An anti-afatinib antibody was obtained using(S)-N-4-(3-chloro-4-fluorophenyl)-7-(tetrahydrofuran-3-yloxy)-quinazoline-4,6-diamine(CTQD), which has the same substructure as afatinib, as a hapten. Enzyme labeling of afatinib with horseradish peroxidase was similarly performed using CTQD. A simple competitive ELISA for afatinib was developed based on the principle of direct competition between afatinib and the enzyme marker for the anti-afatinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Plasma afatinib concentrations below the limit of quantification of 30 pg/mL were reproducibly measurable. Also, the values of plasma afatinib levels measured from 20 patients were comparable with those measured by high-performance liquid chromatography, and there was a strong correlation between the values determined by both methods(Y=0.976 X – 0.207, r=0.975). As indicated by its specificity and sensitivity, this newly developed ELISA for afatinib is an important tool for TDM and studies of the pharmacokinetics of afatinib.

Enzyme-linked Immunosorbent Assay for Detection of Anti-idiotype Antibodies to Antibodies to Ligand of Nicotinic Acetylcholine Receptor in Sera of Patients with Myasthenia Gravis

Anti-bungarotoxin anti-serum,which has the internal image of nicotinicacetylcholine receptor,was used as a tool to measure anti-idiotypic antibodies toantibodies to Iigand of nicotinic acctylcholine receptor in scra from 81 patients withmyasthenia gravis.Enzyme-linked immunosorbcnt assay was adopted.Thc positive ratewas 46.9%(38/81).The specific cross inhibitory test with nicotinic acetylcholinereceptor was positive.Anti-idiotype antibodies to antibodies to ligand of nicotinicacetylcholine receptor in sera of different types of myasthenia gravis patients classified ac-cording to modified Osserman’s standard and myasthenia gravis patients with or withoutthymoma were comparcd in this study and the role of anti-idiotype antibodies toantibodies to Iigand of nicotinic acctylcholinc receptor in the immunity of myasthcniagravis and the possibility of thcrapeutic use of anti-idiotype antibodies arc discussed.

Development of an Indirect Enzyme-Linked Immunosorbent Assay for Seromonitoring Contagious Bovine Pleuropneumonia Using Recombinant Lipoprotein LppQ of Mycoplasma mycoides subsp mycoides SC as Antigen

Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.

A PRELIMINARY STUDY OF SERUM GLYCOCONIUGATES IN PATIENTS WITH CANCER USING THE ENZYME-LINKED LECTIN ASSAY

After primary analyses on the serum glycocon-jugates of lung cancer and normal individul using the enzyme-linked lectin assay (ELLA) with 12 kinds of lectins, PHA and LCA were selected to further study in the sera of 8 kinds of cancers, 4 kinds of non-malignant disease and 1 kind of postoperative cancer. It was found that the test values of 7 kinds of cancers with PHA or LCA were significantly higher than that of the normal (P<0.01); the values of 4 kinds of non-malignant diseases with PHA were not higher (P>0.05); the values of the postoperative cancer with PHA were obviously lower than that of the preoperative (P<0.05). The results showed that the serum glycoconjugates which can bind to PHA seemed related to the cancerous existence in human bodies. The significance of the findings was discussed.

ENZYME-LINKED IMMUNOSORBENT ASSAY OF HUMAN PLACENTA TYPE GLUTATHIONE S-TRANSFERASE AND ITS APPLICATION IN THE DIAGNOSIS OF HEPATOCARCINOMA

GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succinimidyl-4-(N-maleimido-methyl) cyclo-hexane-1-carboxylate (SMCC) as crosslinking reagent to produce Fab'-HRP conjugate. A sandwich ELISA was established for the microquantitative determination of GST-π. The sensitivity was 11 pg/tube, which was far more sensitive than the radioimmunoassay so far reported. Using this method, the serum GST-π of 41 cases normal adult was found to be 1.06±0.94 ng/ml. The upper limit of the normal value was 2.6 ng/ml. In 30 cases of primary hepatocarcinoma, the level of serum GST-π was 24.4± 17.4 ng/ml, which was 23 times higher than the normal average value (P<0.01). The positive rate was 90%. In contrast, serum GST-π in 25 cases of chronic hepatitis was determined to be 1.74±1.16 ng/ml, which was not significantly different from the normal value (P>0.05). The pseudo-positive rate was 12.0%.

A Comparison of Enzyme-Linked Immunosorbent Assay versus Multiplex Methodology Using an <i>in Vitro</i>Model of Pulmonary Hypertension and Inflammation

Enzyme-linked immunosorbent assay (ELISA) is the most widely used method for measuring a single cytokine. Recent developments in cytokine quantification such as multiple arrays measure multiple cytokines simultaneously. Although good correlations between ELISA and multiplex methods have been observed, side by side comparisons are limited. In the present study we hypothesized that ELISA and Luminex techniques are comparable in detecting cytokines in culture medium when pulmonary artery smooth muscle cells (PASMC) are exposed to stress. Primary human PASMC were cultured in modular chambers and exposed to 21% FiO2 and peak inspiratory and positive end expiratory pressure of 24 and 8 cmH2O respectively, and 95% FiO2. At 24 hours, culture medium was collected and assayed for interleukin-6 (IL-6) and IL-8 by quantitative ELISA and by Human Cytokine 25-Plex Panel using a Luminex 200 analyzer. A comparative analysis of agreement between our ELISA and Luminex data was detailed for control and stress conditions using the Bland-Altman plot analysis. Each assay resulted in comparable increased (p < 0.001) levels of IL-6 and IL-8 as compared to control in response to oxidative and biophysical stress. The Bland-Altman analysis demonstrated that 95% of the differences between ELISA and Luminex values were within ±1.96 SD from the mean difference indicated by the 95% limits of agreement for the measurements of IL-6 and IL-8. There was no systematic bias as a function of inflammation level. We conclude that in this cell culture model, ELISA and Luminex are comparable in detecting the levels of IL-6 and IL-8 in the culture medium. If measurements of multiple cytokines are demanded and the amount of sample is limited, Luminex multi-analyte profiling technology is accurate and sensitive.

96份谷子种质资源淀粉多样性及优异资源鉴选利用

采用双波长微量法对国内有代表性的96份谷子种质资源的直链淀粉和支链淀粉含量进行了测定,分析其淀粉多样性与直/支比变异类型。结果表明,各品种直链淀粉含量介于0~24.91%,平均值为15.66%,支链淀粉含量介于4.77%~34.26%,平均值为14.67%;44份育成品种和52份地方品种直链淀粉含量变化幅度分别为8.66%~21.81%和0~24.91%;96份谷子的直/支比变化范围为0~3.60,平均为1.18,其中直/支比<0.05的地方品种仅2个,而直/支比>0.33的品种93个,占总数的96.87%。直链淀粉含量小于3.5%的糯性品种3个,其中完全糯性品种2个;高直链淀粉品种4个,直链淀粉含量介于12.0%~18.0%的种质有60份,占总数的62.50%。筛选出适合加工糍粑、汤圆类糯质食品的地方品种3个,为红毛谷、三爪谷和酒谷;可用于加工米粉等高膳食纤维的地方品种4个,分别为金皇谷、金棒子、茄谷和山西白米。96份谷子种质资源中地方品种直链淀粉变异类型较为丰富,育成品种直链淀粉遗传基础相对单一。

基于智能手机的数字图像比色法增敏研究

本文指出智能手机数字图像比色法是近年来广泛应用的检测方法,图像质量是影响智能手机数字图像比色法结果灵敏度的重要因素,图像质量与光照度、色温和手机本身参数密切相关。本研究探讨了不同的光照度、色温和手机参数是否影响智能手机数字图像比色法灵敏度。实验结果表明,手机参数感光度对数字图像比色法的灵敏度几乎无影响,但是曝光补偿和快门速度的影响比较大;曝光补偿为-3和快门速度为2500 s,提高智能手机图像比色法的灵敏度;在不同的光照度和色温实验中,发现光照度和色温不能提高智能手机数字图像比色法的灵敏度。本方案检出限为0.0057μmol/L,具有较好的重复性。检测低、中、高物质的量浓度样本时,其标准偏差(RSD)分别为3.29%、3.26%、1.63%。本课题研究的优化方案提高了智能手机检测的灵敏度,为智能手机在现场检测方面提供了参考依据。

智能手机辅助双探针比色法检测α-葡萄糖苷酶

该文以3,3',5,5'-四甲基联苯胺(TMB)和罗丹明B为比色探针,建立了α-葡萄糖苷酶的比色检测方法,并在此基础上基于智能手机策略,通过RGB值对α-葡萄糖苷酶进行检测。结果表明,Fe^(3+)-TMB-罗丹明B显色体系的吸光度与α-葡萄糖苷浓度在20~100 U/L范围内呈线性关系,检出限为3.3 U/L。采用photo⁃shop软件分析样品图像和样品荧光图像的RGB值,其与α-葡萄糖苷酶浓度在10~100 U/L范围内呈线性关系,检出限分别为2.5 U/L和1.2 U/L。该法已成功用于α-葡萄糖苷酶抑制剂阿卡波糖抑制率评估和胎牛血清中α-葡萄糖苷酶浓度的测定。所构建的智能手机辅助检测法为α-葡萄糖苷酶的临床分析和酶抑制剂的快速筛选提供了简便、快捷和准确的方法。

基于点击化学和非巯基DNA修饰纳米金的维生素C检测

目的建立一种基于点击化学和非巯基DNA修饰的叠氮纳米金的可视化维生素C(vitaminC,VC)检测方法。方法用一端有多个腺嘌呤核苷酸的非巯基DNA修饰纳米金,再与一端有叠氮基的互补链杂交,形成表面暴露出叠氮基团的叠氮纳米金。在VC的存在下,将Cu^(2+)还原成Cu^(+),催化叠氮纳米金与三炔丙基胺发生点击化学反应,使叠氮纳米金聚集,引起光谱和颜色的变化。通过光谱和颜色的变化进行VC检测。结果在pH为7、Cu^(2+)浓度为100μmol/L、三炔丙基胺浓度为3μmol/L和反应时间12 min的最优条件下,用分光光度计检测VC的检出限为0.042mg/L,目视的检出限为0.05mg/L。该方法成功用于饮料中VC的测定,呈现了良好的回收率,从而验证了该方法的可靠性和可行性。结论这项研究提供了一种简便、超灵敏的VC检测方法,可用于VC的微量可视化检测。

运用虚拟仿真技术,打造实验实践教学与理论知识及产业实践之间的有效连接

本文旨在解决实践教学与产业实际之间存在的连接问题,以染整领域中的颜色学为研究对象,为解决实验课程中的关键难题,利用虚拟仿真技术构建仿色仿真系统,为学生提供开放性的实验课程设计平台。这种结合了虚拟仿真和实际操作的训练方法,成功架起了实验实践教学与产业实际之间的桥梁。结果表明,这种方法可以使学生的课程目标达成度提升至0.87,显著提高学生对理论知识的掌握程度。

人参联合咖啡因对大鼠的抗疲劳作用及机制探讨

目的评估人参联合咖啡因对大鼠的抗疲劳作用及机制。方法将SD大鼠随机分为空白组、模型组、人参组(60 mg·kg^(-1))、咖啡因组(3.0 mg·kg^(-1))、配伍组(30 mg·kg^(-1)+1.5mg·kg^(-1)),建立大鼠负重游泳疲劳模型,每日给药1次,连续给药21 d;采用负重游泳实验评价药物抗疲劳作用;采用两成分组合效应系数(two components combination index,TCCI)方法评估人参配伍咖啡因抗疲劳协同增效作用;比色法检测各组大鼠的尿素氮(BUN)、乳酸(LD)和肝/肌糖原水平;酶联免疫吸附法检测各组大鼠白细胞介素6(IL-6)、白细胞介素1β(IL-1β)和C反应蛋白(CRP)水平;使用网络药理学初步探讨人参联合咖啡因抗疲劳的可能作用机制。结果人参联合咖啡因TCCI值在0.17~0.61,两者联用显示明显的协同增效作用;与模型组相比,各给药组可不同程度地延长大鼠负重游泳时间,提高肝脏/骨骼肌组织中糖原含量,下调血清中尿素氮水平,降低炎症因子水平;通过网络药理学分析发现,其主要通过PI3K-Akt和MAPK等通路发挥抗疲劳功效。结论人参联合咖啡因可显著降低糖原分解和乳酸等代谢物积累,改善模型大鼠的疲劳症状。

药用辅料羟丙基甲基纤维素的细胞毒性研究

目的采用MTT比色法进行羟丙基甲基纤维素(HPMC)体外细胞毒性试验,以评价HPMC作为药用辅料的生物安全性。方法将L929细胞分为空白对照组(只加细胞培养液)、HPMC组(K4M、K100M两种规格,浓度分别为10.0、5.0、1.0、0.5、0.1 mg/ml)。置于培养箱中培养24、48 h,用MTT方法测定490 nm处的吸光度值,计算细胞毒性试验中细胞相对增殖率(RGR)。结果不同规格(K4M、K100M)、不同浓度(10.0、5.0、1.0、0.5、0.1 mg/ml)HPMC的平均细胞RGR>85%,属于无细胞毒性。结论研究结果证实HPMC对L929细胞无细胞毒性,这说明HPMC的细胞毒性达到国家标准对生物材料细胞毒性所限定的要求,为安全的药用辅料。

基于MTT比色和响应面法优化侧孢短芽孢杆菌最大活菌数培养条件

目的:探索获得侧孢短芽孢杆菌(Brevibacillus laterosporus)最大活菌数的最佳培养基成分及培养条件。方法:在建立MTT比色法与平板计数法的相关回归方程基础上,对获得最大活菌数的侧孢短芽孢杆菌最适培养基成分(碳源、氮源、无机盐)和培养条件(初始pH、温度、接种量、磷酸二氢钾)进行优化。结果:MTT比色法与平板计数法对活菌数测定结果表现出显著的线性关联(R^(2)>0.999);麦芽糖、氯化钙、初始pH、磷酸二氢钾为显著影响因子,最佳发酵条件为麦芽糖8.75 g/L,氯化钙0.17 g/L,初始pH 7.07、磷酸二氢钾3.73 g/L,此条件下活菌数为8.12×10^(8)CFU/mL,与理论活菌数(8.25×10^(8)CFU/mL)无显著差异。结论:基于MTT比色和响应面法优化侧孢短芽孢杆菌最大活菌数培养条件,优化后的活菌数较优化前提高了3.02倍。

前牙瓷贴面美学修复体比色的影响因素

瓷贴面修复具有微创、美观和生物相容性良好等优势,是目前较主流的前牙美学修复技术。然而,瓷贴面修复体的比色是决定美学修复效果的重要因素。综合考量比色可以使瓷贴面与周围天然牙融为一体,从而实现自然、美观、功能相协调。该综述旨在从视觉方法和数字化方法角度探讨前牙瓷贴面美学修复体比色的影响因素,为临床提供细化且具操作性的参考。

一种基于残差网络改进的牙齿颜色分类模型

针对传统牙齿比色方法准确率低和效率低等问题,提出一种基于残差网络改进的牙齿颜色分类模型。该模型通过融合多层卷积结果以及引入压缩与激励注意力机制模块的方式,使网络能学习到更多的图像颜色特征。基于典型牙齿所建数据集进行颜色分类实验,在该数据集上对文中模型与GoogleNet、MobileNet-V1、ResNet-34和ResNet-50等模型进行颜色分类预测结果比较。实验结果表明,文中模型优于传统模型,预测分类准确度达到91.16%,有效提高了牙齿颜色分类准确率和效率。