Analytical Methods
·
2013
·Vol. 5
·期 21
·6106-6113
·
IF 1.855
Yajing Lei,Lizheng Fang,Muhammad Sajid Hamid Akash,Zhiming Liu,Weixing Shi,Shuqing Chen
Bisphenol A (BPA) is widely used to manufacture polycarbonate plastics and epoxy resins, which are in widespread use in China. Concerns about potential health impacts from exposure to BPA among the general population are increasing day by day. A sensitive and specific antibody was prepared to develop and compare direct and indirect competitive enzyme-linked immunosorbent assays (ELISAs) for the determination of BPA in human urine. The IC50 value and limit of detection (LOD) for the direct competitive ELISA were 5.5 ng mL−1 and 0.03 ng mL−1 respectively whereas, for the indirect competitive ELISA, the IC50 value and LOD were 7.0 ng mL−1and 0.08 ng mL−1, respectively. We found that the direct competitive ELISA was more specific and sensitive than the indirect competitive ELISA. The established immunoassays were also applied in the determination of BPA in human urine samples. The results from fortified samples and real samples indicated that the direct competitive ELISA was more sensitive and reliable for the measurement of BPA in human urine as compared to the indirect competitive ELISA.
研究领域:
环境健康
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分析化学
·
毒理学
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DOI
高影响因子
IEEE SENSORS JOURNAL
·
2024
·Vol. 24
·期 22
·36239-36246
·
IF 4.3
Dong Zhao,Honglie Chen,Kun Yang,Haoyu Wang,Xing Guo,Yang Ge,Xiushan Dong,Shengbo Sang
The application of competitive immunoassay brings many advantages to the detection of trace biomolecules and has the potential to be applied to urine-based clinical practice. However, this type of detection method has strict requirements for secondary antibody incubation processes and analysis equipment, leading to strong demands for convenient, rapid, and inexpensive detection platforms. In this study, a mechanical competitive immunosensor (MCI) was proposed for the detection of human serum albumin (HSA) based on goat anti-rabbit @Fe2O3 magnetic beads with magnetic sensitization. With the doping of Fe2O3, the conversion layer of MCI responds more accurately and rapidly to stress. In addition, goat anti-rabbit conjugated with animated Fe2O3 nanoparticles were introduced as secondary antibodies for signal amplification. Under the synergistic effect of the magnetic force of magnetic beads and the stress caused by the specific binding of antigen and antibody, the deformation of the film was amplified, which can effectively change the conductive pathway formed by doped carbon nanotubes, resulting in a larger output electric signal. Through competitive immunoassay for HSA, a limit of detection (LOD) of 68 ng/mL was achieved, which was an order of magnitude lower than direct detection methods. With high reproducibility and stability, MCI demonstrated effectiveness in the detection of HSA at a clinically significant concentration range (0.1–
$50 \; \mu $
g/mL). Moreover, MCI showed excellent specificity and selectivity, which held promise to offer an alternative tool for clinical diagnosis of urine HSA levels in nephrotic patients.
研究领域:
生物医学工程
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分析化学
·
纳米技术
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DOI
高影响因子
Food & Function
·
2015
·Vol. 6
·期 6
·2008-2016
·
IF 2.791
Liang Zeng,Jingna Yan,Liyong Luo,Dongying Zhang
Disorders of blood lipid metabolism are the primary risk factors for many diseases. Recently, the effect of Pu-erh tea on blood lipid metabolism has received increasing attention. However, the mechanism underlying its ability to regulate blood lipid metabolism is unclear. We set out to study this through assessing the effects of Pu-erh tea aqueous extract (PTAE) on the central enzymes of blood lipid metabolism, including lipoprotein-associated phospholipase A2 (Lp-PLA2), lecithin: cholesterol acyltransferase (LCAT), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) and pancreatic lipase (PL). We find that the Lp-PLA2, HMRG and PL activities are inhibited by PTAE in a dose-dependent manner and that the LCAT activity tends to increase with increasing PTAE concentrations. Lineweaver–Burk plot analyses reveal that PTAE acts as a competitive inhibitor for HMGR and PL and as a noncompetitive inhibitor for Lp-PLA2. Moreover, we determine that its active ingredients include catechins, gallic acid, caffeine, free amino acids, and soluble sugar. However, the effect of each ingredient and whether any of them have synergistic effects are still unknown. The results suggest that Pu-erh tea has a potent ability to regulate blood lipid metabolism and knowledge of the mechanisms provides insights into its potential therapeutic application as an alternative hypolipidemic drug.
研究领域:
营养学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2025
·
IF 3.7
Zhili Shi,Ya Li,Weibo Shi,Zhixin Mu,Qingxi Han,Weiwei Zhang
Probiotics are prior agents for treating bacterial infection with advantages of inhibiting pathogenic bacteria and improving immune responses of hosts, thus increasing the survival rate of cultured animals. In this study, one Vibrio parahaemolyticus YDE17 pathogenic to shrimp and its antagonist Glutamicibacter sp. ZY1 were screened, and ZY1 showed stable inhibitory effects on diverse Vibrio spp., especially V. parahaemolyticus. ZY1 secreted inhibitory substances into supernatant, and the activity of inhibitory substances did not change after being treated under different temperatures, proteinase K, and pH (6-10), which indicated that the inhibitory substances might be small molecules, which led us to trace the siderophore production. The siderophore production of YDE17 co-incubated with the cell-free supernatant of ZY1 was greater than that of YDE17 alone, which indicated that the cell-free supernatant of ZY1 created iron-limiting conditions for YDE17. This finding was confirmed by iron supplementation assays, in which the inhibitory activity of the cell-free supernatant of ZY1 on YDE17 as well as the siderophore production of YDE17 decreased in the presence of FeCl3. The effect of iron on inhibition was further confirmed by in vivo infection. The relative percent survival of ZY1 to shrimp challenged by YDE17 was 83.3%, but the survival rates of shrimp challenged with YDE17/ZY1/FeCl3 were similar to that of YDE17, both of which were significantly lower than the 70% survival rate of shrimps simultaneously challenged by ZY1/YDE17. Our study offers a new probiotic resource to control vibriosis, which works through iron competition with the opportunistic pathogens of Vibrio spp.
研究领域:
微生物学
·
水产养殖
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病原生物学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Junyi Xiang,Xi Lu,Hongru Rao,Luwei Bai,Qingyun Huang,Xuewei Lv
The separation of vanadium and chromium from vanadium-chromium slag constitutes the greatest bottleneck in the exploitation and utilization of high-chromium vanadium-titanium magnetite, which mainly results from the insufficient understanding of the behavior of similar elements vanadium and chromium during the extraction process. In this research, a series of spinels FeV x Cr 2- x O 4 (0 ≤ x ≤ 2) were synthesized via the high-temperature solid-state method, and their sodium roasting and leaching behavior were comprehensively analyzed. The transformation rules of sodium vanadate and chromate were investigated by XRD, SEM-EDS, FTIR, and thermodynamic calculation. The results indicate that in the FeV x Cr 2- x O 4 (0 ≤ x ≤ 2) − Na 2 CO 3 system, at 300°C, a portion of chromium spinel phase is preferentially and slowly oxidized to Cr 2 O 3 , while the vanadium spinel rapidly oxidizes to form NaVO 3 at 400°C. Above 500°C, NaVO 3 further reacts with Na 2 CO 3 to form Na 4 V 2 O 7 , and Na 2 CrO 4 also begins to form concurrently. As the proportion of Cr in FeV x Cr 2- x O 4 increases, both the leaching efficiencies of vanadium and chromium from the sodium-roasted samples decrease, with the leaching efficiency of chromium decreasing more significantly. Significant competitive and synergistic effects between vanadium and chromium are observed in the roasting of FeV x Cr 2- x O 4 with Na 2 CO 3 . This study is expected to provide theoretical support for the development of efficient vanadium-chromium extraction processes.
研究领域:
冶金学
·
材料科学
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DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Kejia He,Qiang Song,Zhennan Yan,Na Zheng,Qiang Yao
Alkaline injection is an effective way to control the emission of high concentration SO 3 caused by the use of high-sulfur coal and selective catalytic reduction (SCR), but its performance is affected by the competitive absorption of SO 2 . A fixed-bed reactor was used to study the competitive absorption of SO 3 and SO 2 by Ca(OH) 2 . The dynamic absorption curves in different atmospheres were obtained, the intermediate products were characterized, and the competitive absorption mechanism was discussed. The absorption of SO 3 and SO 2 consists of the chemical kinetics-controlled and product layer diffusion-controlled stages. In the chemical kinetics-controlled stage, the SO 3 and SO 2 removal efficiencies were around 90% and 55% at first and then decreased; the SO 3 selectivity was around 0.1 at first and then increased. In the product layer diffusion-controlled stage, the SO 3 removal efficiency gradually decreased but kept greater than 10%, while the SO 2 removal efficiency deceased to zero; the SO 3 selectivity continued to increase and reached 0.31 at most when SO 2 absorption ceased. There existed significant competition between SO 3 and SO 2 absorption. The increasing SO 3 concentration promoted the SO 3 absorption and the increasing SO 2 concentration decreased it. The absorption of SO 3 increased the intensity of the SO 4 2 - band, decrease the intensity of the SO 3 2 - band, and made the product layer more compact. The possibility of SO 3 reacting with the components (CaSO 3 , CaSO 4 and CaCO 3 ) on the reacted Ca(OH) 2 surface was analyzed. Ionic diffusion was proposed as the main mechanism of the continuous SO 3 absorption after the formation of a dense product layer.
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Weiqing Liu,Haiyan Jiang,Jing Shi,Bingjun Lu,Hongfeng Cai,Zhimin Mao,Fantai Kong
The photoanode of a dye-sensitized solar cell is composed of titanium dioxide and a dye adsorbed on the surface. Dye molecules, such as N719 dye, usually agglomerate due to H bond and other factors, forming a multilayer adsorption structure, leading to light loss and electron injection loss. Adding a co-adsorbent to the dye, such as chenodeoxycholic acid (CDCA) molecule, is an effective method to prevent the aggregation of the dye. However, the mechanism of interaction between CDCA and N719 is still unclear. Therefore, in this paper, the mechanism of interaction of CDCA and N719 was studied in detail using quartz crystal microbalance (QCM) combined with UV–vis absorption spectrum. The adsorption kinetics constant of the co-adsorbent CDCA was obtained, and it was found that the adsorption process of CDCA on the surface of TiO2 was more consistent with the Freundlich isothermal adsorption model. Under the condition of continuous adsorption and desorption, the dynamic constants of CDCA adsorption did not change obviously, but molecular rearrangement might occur. In the process of sequential competitive adsorption, pretreatment with CDCA had a small influence on the adsorption kinetic constants of N719. There is competitive adsorption between CDCA and N719 on the surface of TiO2. In the process of mixed adsorption, the interaction mechanism between CDCA and N719 is a cooperative mechanism in the solution and competitive mechanism on the TiO2 surface. In addition, the results of this experiment also showed that CDCA could accelerate the adsorption time of N719. The experimental results in this paper may be helpful for understanding the mechanism of CDCA.
研究领域:
材料科学
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光化学
·
表面化学
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DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 10
·1829
·
IF 2.847
Liwen Zheng,Yongchao Gao,Jianhua Du,Wen Zhang,Yujie Huang,Qingqing Zhao,Luchun Duan,Yanju Liu,Ravi Naidu,Xiangliang Pan
The chitosan–EDTA modified magnetic biochar (E–CMBC) was successfully used as a novel adsorbent to remove heavy metals. The adsorption behaviour and mechanisms of E–CMBC to Cd2+, Cu2+and Ni2+were performed in single and binary system in aqueous solutions. In single–metal system, the adsorption process of Cd2+, Cu2+and Ni2+on E–CMBC fitted well with the Avrami fractional–order kinetics model and the Langmuir isotherm model. The measured maximum adsorption capacities were 61.08 mg g−1, 48.36 mg g−1and 41.17 mg g−1for Cd2+, Cu2+and Ni2+, respectively. In binary–metal system, coexisting ions have obvious competitive adsorption behaviour on E–CMBC when the concentration of heavy meal beyond 20 mg L−1. The maximum adsorption capacities of the heavy metals were found to be lower than that in single–metal system. The order of the competitive adsorption ability was Cu2+> Ni2+> Cd2+. Interestingly, in Cd2+–Cu2+system the earlier adsorbed Cd2+could be completely replaced by Cu2+from the solution. Different competitive adsorption ability of those heavy metal were due to the characteristics of heavy metal and resultant affinity of the adsorption sites on E–CMBC. The adsorption mechanism indicated that chemical adsorption played a dominating role. Therefore, E–CMBC could be a potential adsorbent for wastewater treatment.Keywords:modified biochar;heavy metals;competitive adsorption;mechanisms
研究领域:
环境科学
·
化学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 9
·1-13
·
IF 5.3
Kang Jia,Qi Meng,Wang Yasen,Li Linchun,Zhou Xinda,An Xiaoshuo,Hammock Bruce D.,Zhang Jinlin,Huo Jingqian
Nanobodies specifically recognizing atrazine were successfully obtained through immunization of alpacas and phage display libraries, and an indirect competitive immunoassay (ic-ELISA) based on nanobodies was constructed with an IC 50 of 0.062 μg/mL and a minimum detection limit of 0.01 μg/mL. An Au@PtNPs with excellent colorimetric performance, high catalytic activity, and high stability was synthesized. The combination of Au@PtNPs and nanobodies led to the development of a direct competitive immunoassay (dc-ELISA) with higher specificity, convenience, lower cost and an IC 50 value of 0.032 μg/mL which was lower than the ic-ELISA. Based on the Au@PtNPs and nanobodies, a novel LFIA model for qualitative and semi-quantitative detection of atrazine was constructed with a visual detection limit of 5 ng/mL. The present study is of great significance for the construction of atrazine immunoassay combining nanobodies and nanoenzymes, which provides a sensitive, specific, simple and reliable method for the detection of atrazine in the environment.
Graphical
研究领域:
分析化学
·
免疫学
·
纳米科技
·
环境科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·
IF 3.5
Yu Fengqin,Xie Qiang,Zhang Zhijun,Yang Shuai,Liu Jinchang,Ren Qiang,Liang Dingcheng
Zeolites are widely used for removing volatile organic compounds (VOCs) in industrial processes. However, the understanding of the competitive adsorption behavior of multicomponent VOCs on zeolites remains insufficient. This study employed grand canonical Monte Carlo simulation to investigate the adsorption behaviors of nonpolar benzene and polar ethyl acetate in both pure and mixed forms on FAU, LTA and MFI zeolites. The effects of zeolite topology, Si/Al ratio, and compensating cations on competitive adsorption were explored. The results revealed that the adsorption capacities of benzene and ethyl acetate on FAU and LTA zeolites gradually increased with increasing Si/Al ratio, consistent with the increasing trends in their specific surface areas and pore volumes. However, the MFI zeolite shows no significant change in these properties with varying Si/Al ratios. Zeolites modified with Ca 2+ significantly improved the benzene and ethyl acetate adsorption capacities, while impact on ethyl acetate adsorption is minimal. Zeolites modified with K + reduced the adsorption capacities for both benzene and ethyl acetate. For binary mixtures, Na-FAU-1, Na-LTA-1, and Na-MFI-15 exhibited high selectivity for ethyl acetate. Increasing the Si/Al ratio and K + -modification reduced the adsorption selectivity of these zeolites for ethyl acetate. Ca 2+ -modification reduces the selectivity of LTA-1 toward ethyl acetate, with minimal impact on FAU-1 and MFI-15. Dynamic adsorption experiments with commercial zeolites confirm the reliability of the simulation results in predicting benzene and ethyl acetate adsorption performance. This study is expected to provide guidance for selecting appropriate zeolites for VOCs mixtures in practical applications. Graphical abstract
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
FOOD AND AGRICULTURAL IMMUNOLOGY
·
2024
·
IF 1.7
Jiaxin Wang,Wenhua Shang,Shibei Shao,Jialin Zhang,Qiuyang Wu,Min He,Licai Ma,Jianzhong Shen,Zhanhui Wang,Kai Wen
Paxilline (PAX) is a tremorgenic mycotoxin that is thought to be associated with various syndromes in animals. To facilitate the determination of this toxin, a hapten was chemically synthesized and then respectively conjugated to Bovine Thyroglobulin (BTG) and Bovine serum albumin (BSA) for antibody production. Monoclonal antibody (mAb) 4F8 was finally obtained and used to establish an accurate and sensitive indirect competitive ELISA (icELISA). Various parameters that could impact the performance of icELISA were optimized, including the ion concentration, pH value and organic solvent. Under optimal condition, this assay exhibits an IC50 value as low as 0.84 µg L−1. The limit of detection (LOD) of the established icELISA method for PAX was 0.03–0.3 µg L−1. In conclusion, this study provided a rapid, sensitive, and high-throughput immunoassay for the detection of PAX in grains.
研究领域:
免疫学
·
食品科学
·
毒理学
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产品关联
DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2021
·Vol. 45
·期 4
·e13638
·
IF 2.72
Xin Lu,Qiang Sun,Lixia Zhang,Ruidan Wang,Jinhong Gao,Cong Jia,Jinian Huang
To prepare and identify ACE-inhibitory peptides originated from sesame seed protein, peptides with strong ACE-inhibitory activities were obtained via the optimization of protease and hydrolysis conditions, and these peptides were purified and identified by membrane separation, gel filtration, and liquid chromatography–mass spectrometry. Results showed that the dual-enzyme comprised alcalase and trypsin with the enzyme activity ratio of 3:7 was suitable to produce ACE-inhibitory peptides. The highest ACE-inhibitory activity of 98.10 ± 0.26% was obtained at the following parameters, pH 8.35, E/S ratio of 6,145 U/g, and hydrolysis time of 4.4 hr. ISGAQPSLR and VVISAPSK ranked the first and second ACE-inhibitory activity among 15 identified ACE-inhibitory peptides. Both peptides influenced ACE via binding with the S1 pocket, S2 pocket, and Zn 2+ ion. ISGAQPSLR even impacted the S1′ pocket. ISGAQPSLR and VVISAPSK acted as a competitive and noncompetitive inhibitor, respectively. ACE-inhibitory peptides derivated from sesame seed protein have potential applications in functional food. Practical applications Although sesame seed protein is proven as the precursor of ACE-inhibitory peptide, preparing ACE-inhibitory peptide from sesame seed protein is still suffering from insufficient information on hydrolysis condition and the peptide sequence. Therefore, the performance of the typical protease on preparing ACE-inhibitory peptide from sesame seed protein has been evaluated, the effect of the amino acid composition of sesame seed protein and cleavage specificity of protease on the generation of ACE-inhibitory peptide has been investigated, hydrolysis conditions have been optimized, the peptide sequence has been identified to illuminate the effect of sesame seed protein fraction on the formation of ACE-inhibitory peptide and discuss the structural characteristics. ACE-inhibitory peptides originating from sesame seed protein could apply in functional food. It is promising for dual-enzyme hydrolysis to utilize in preparation of high-value bioactive peptides.
研究领域:
食品科学
·
生物化学
·
药理学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）