Although Enzyme-linked immunosorbent assay (ELISA) has been widely used for biomedical research, simultaneous sensitive and cost-effective detection of multiple biomarkers is challenging. Herein, we proposed a "onepot" nicking endonuclease signal amplification (NESA)-based fluorescent aptasensor for simultaneous detection of carcinoembryonic antigen (CEA) and alpha fetoprotein (AFP). Firstly, two aptamers were synchronously immobilized on the surface of magnetic nanoparticles (MNPs) by coupling with two complementary DNA (cDNA). CEA and AFP specifically recognized the aptamers and then the released cDNA (ssDNA) from the doublestrands (dsDNA) triggers NESA, further breaking two detection probes which were labeled with the fluorescent dye (FAM and ROX) and its quencher (BHQ1 and BHQ2) at the same time. Then, the fluorescence signal of FAM and ROX were restored separately. The results indicated that the fluorescence intensity at the emission wavelength of 518 nm and 610 nm had a positive correlation with CEA and AFP concentrations, respectively. Under the optimum conditions, wider liner range of 1-500 ng mL- 1 to CEA and 5-800 ng mL- 1 to AFP of this fluorescent aptasensor were successfully obtained, achieving a detection limit of CEA and AFP were 0.7 ng mL- 1 and 2 ng mL- 1, respectively. Hence, it turned out that the aptasensor strategy can be a promising candidate for developing a newly fluorescence assay for the simultaneous quantitative detection of multiple tumor markers in matrix samples by changing the corresponding sequences of aptamer and fluorescent signal probe, which has great potential for the screening of early cancer.

为培养创新型公共卫生与预防医学专业人才,对卫生化学实验教学进行了深层次的改革.教学团队秉承"科教融合、学术育人"的教学理念,结合学科内容与预防医学发展现状,实现交互式教学和线下实训、虚拟仿真混合式实验教学方法,发挥各教学资源的优势互补,夯实基础促进理论与实践之间的有效衔接,从而激发学生的学习兴趣,培养其分析与解决问题的能力,提高卫生化学实验教学质量.课程调查问卷结果表明:学生对教师的在线辅导答疑、教师授课速度、师生互动等满意度较高,故所构建的科教融合理念下实验教学模式符合我校预防医学专业学生的求知需求,有利于新时代背景下公共卫生与预防医学专业人才的培养.

目的:了解22个产地的黑果枸杞中主要矿质元素的分布特点.方法:22份黑果枸杞样品经微波消解法处理,用国家标准方法测定K、Ca、Na、Mg、Fe、Co、Zn、Mn、Cu、Cr、Ni、Pb和P元素的含量,用主成分分析(除Pb)进行产地综合排名并用聚类分析进行产地聚类.结果:黑果枸杞含有多种有益的矿质元素,且重金属Cu和Pb的含量符合《中国药典》安全标准.主成分分析结果显示,产自新疆的黑果枸杞样品综合得分较高,矿质元素含量较多;而产自西藏的黑果枸杞样品综合得分较低,矿质元素含量较少.聚类分析结果与主成分分析结果基本一致.结论:黑果枸杞含有丰富的矿质元素,但不同产地的含量不同,品质各异,可为其进一步的综合开发利用提供数据支持.

目的:基于细胞代谢组学分析探究蒲公英提取物抗肿瘤作用的可能机制.方法:采用CCK-8实验检测不同质量浓度(0、5、10、25、50、100、200、400、800 mg/L)的蒲公英提取物处理细胞24 h对人非小细胞肺癌A549细胞活力的影响.以25 mg/L蒲公英提取物处理A549细胞(干预组),未处理的A549细胞为空白对照.24 h后,检测细胞活力,基于超高效液相色谱-质谱联用技术对2组细胞样品进行代谢组学分析.采用主成分分析及正交偏最小二乘判别分析法对数据进行模式识别,分析2组的代谢谱差异,进一步筛选差异代谢物,并分析代谢途径以探讨抗肿瘤机制.结果:蒲公英提取物可抑制A549细胞活力,其作用随剂量升高有增强的趋势(P<0.001).与空白对照组比较,干预组细胞活力受抑(P<0.05).2组细胞的代谢谱差异有统计学意义,共筛选并鉴定出136种差异代谢物,其中50种差异代谢物上调,86种下调,主要涉及嘌呤代谢、嘧啶代谢以及氨基糖和核苷酸糖代谢3个代谢通路.结论:蒲公英提取物可抑制A549细胞活力,其机制可能与影响多种能量及氨基酸代谢,从而扰乱A549细胞的生长和增殖等生命活动有关.

化妆品是人们生活中接触最多的日用品之一,可以清洁、保护和美化皮肤.在化妆品中添加性激素短期内可以起到快速的美容护肤功能,但是长期使用后却会造成色素沉积、皮肤萎缩变薄,甚至具有致癌风险.《化妆品安全技术规范》(2015年版)中明确规定,化妆品中禁止添加雌二醇、雌三醇、雌酮、己烯雌酚、睾酮、甲基睾酮、黄体酮等性激素[1].因此,卫生化学实验课为学生开设了综合设计实验"化妆品中7种禁用性激素的测定与评价".由学生自行查阅文献,设计实验方案(包括样品前处理方法和仪器分析方法),进行实际样品的测定并对分析结果进行评价.

This work aimed to develop an ultrasensitive and specific immunosorbent assay for simultaneous detection of double DNA methylation marks. Being considered the most important indicators in disease diagnosis, clinical treatment, and prognosis, 5- methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) were chosen as the proof-of-concept targets. The described strategy consisted of Phos-tag Biotin anchoring at streptavidin-magnetic nanoparticles, specific immune recognition of anti-5mC antibody and anti-5hmC antibody and labeling of Barcode-antibody, signal amplification of immune PCR and digital PCR machine. Under optimal conditions, the digital immuno-PCR assay showed a board dynamic range from 2.7 x 10(-13) mol/L to 2.7 x 10(-9) mol/L and the detection limits were 61.7 fmol/L for 5mC, and of 0.111 pmol/L for 5hmC. A 16-fold and 186-fold improvement of LOD were obtained by the proposed approach for 5mC and 5hmC detection compared with real-time immune PCR. The approach also showed ideal specificity, repeatability and stability. The recovery test demonstrated that the digital immuno-PCR assay is a promising platform for the simultaneous determination of the two DNA methylation marks in human serum sample. (c) 2021 Elsevier B.V. All rights reserved.

A method is described for the simultaneous determination of the carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA21-1). Two kinds of CdSe/ZnS quantum dot nanobeads (QBs), with emission maxima at 530 nm (green) and 585 nm (yellow), were used as labels, and magnetic beads (MBs) for separation. The MBs were used as substrates to couple CEA and CYFRA21-1 antibody for isolating the proteins. Then, the differently colored QBs were linked to the antibodies against CEA and CYFRA21-1, respectively. Following the formation of the immunocomplex, the intensities of the green and yellow emissions were measured at the same excitation wavelength of 340 nm. The detection limits are 0.1 ng⋅mL− 1 for CEA, and of 0.2 ng⋅mL− 1 for CYFRA21-1. The recoveries from spiked serum are 92.1 - 118.1% for CEA, and from 90.8% to 115.2% for CYFRA21-1, with the relative standard deviations of 6.3 - 12.3% and 7.1 - 11.8%. The method was successfully applied to the simultaneous determination of the two proteins in human serum sample (n = 45). The results correlated well with those of the chemiluminescent enzyme immunoassay kit.

为评价不同产地黑果枸杞的蛋白质营养价值,采用GB 5009.124-2016法测定6省22地区黑果枸杞的氨基酸含量,并用氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)、生物价(BV)、营养指数(NI)评价其蛋白质营养价值,用主成分分析(PCA)和聚类分析(CA)比较产地间的差异性.结果 显示,样品氨基酸总量5.24～10.76g/100 g;蛋氨酸+半胱氨酸为第一限制氨基酸;AAS、CS、EAAI、BV和NI分别为42.48％～66.70％,17.14％～26.91％,53.81～71.43,46.96～66.16和3.59～6.91;甘肃白银、青海德令哈、新疆阿勒泰黑果枸杞的蛋白质营养价值较高,新疆哈密、青海格尔木、内蒙古额济纳旗较低.结果 表明,不同产地的黑果枸杞品质有所差别,但总体上氨基酸种类齐全、含量丰富、配比合理,具有较高的蛋白质营养价值和药用价值.

DNA methyltransferasesl (DNMT1) , a dominant enzyme responsible for maintaining the genetic stability of DNA methylation, is closely related to the occurrence and development of a variety of tumors. However, till now, most of the studies on DNA methyltransferases (DNMTs) detection have focused on prokaryote methyltransferases and been limited to laboratory studies. Therefore, a fluorescence immunoassay (FLISA) for the high sensitivity and high throughput detection of DNMT1 level in human serum samples was established to provide new ideas for early cancer diagnosis and clinical cancer therapy. The functional carboxyl Fe3O4 magnetic beads were used as solid phase carriers. 1-chloride-3-dimethylamino-propyl-3-ethylcarbodiimide hydrochloric acid (EDC) and sulfo-N-hydroxysuccinimide (Sulfo-NHS) were used as coupling agents to prepare immune-magnetic capture probe Fe3O4 @ McAb(DNMT1) (monoclonal antibody DNMT1). After that, the immune-fluorescent detective probe 5-TAMRA@PcAb(DNMT1) (5-carboxytetramethylrhodamine@polyclonal antibody DNMT1)was also made. Their structure and activity were characterized by infrared absorption, UV-Vis spectra, Zeta potential and immunocompetence. Then, the content of DNMT1 in human serum samples was detected based on the double-anti-sandwich method by FLISA with high sensitivity. Finally, methodology evaluation and comparison were conducted. The results showed that the probes conjugated successfully and maintained the immunocompetence of the original antibody. The linear equation was y= 222. 046+48. 323x, the linear range was 0. 05 similar to 80 ng . mL(-1), and the correlation coefficient was 0. 991 4, the detection limit was 0. 005 ng . mL(-1), the intra-and interpanel RSD was 4. 7%similar to 8. 8% and 1. 6%similar to 10. 0% (n= 6) , respectively, intra- and inter-panel recoveries were 91. 3%similar to 102. 4% and 88. 0%similar to 98. 8% (n=6), respectively. The cross-reactivity rates with other two DNA methyltransferase 3a/3b were lower, and the specificity of FLISA was well. Compared with ELISA and MELISA, FLISA has the lowest detection limit and shortest analysis time. Compared with ELISA kits, the result displayed a high correlation between two methods, and the difference of them was not statistically significant (p>0. 05). The result suggests that the FLISA system would be used to detect multiple samples at the same time for the rapid analysis of DNMT1 in human serum samples.

Iron, copper oxides composite particles (Fe/Cu oxides CPs) were produced using rapid, single-step, green and sustainable pathway from biomolecules of pine needle extract and were adopted as a potential adsorbent for the removal of norfloxacin (NOR) and ofloxacin (OFLX) from aqueous solution. To understand the morphologies and properties of Fe/Cu oxides CPs, surface analysis via SEM image, EDS, TEM, XPS, BET and FTIR pattern were employed. The effects of factors such as contact time, reaction temperature, initial pH, initial concentration and ionic strength on the adsorption capacity of NOR or OFLX onto Fe/Cu oxides CPs were studied. Kinetic analysis confirmed that the kinetic data were well described by Double-constant rate equation. The experimental equilibrium data were well fitted by Redlich-Peterson, Koble-Corrigan and Dubinin-Radushkevich models and the maximum adsorption capacity of Fe/Cu oxides CPs calculated by Langmuir model for NOR and OFLX was 1.64 mmol/g and 1.26 mmol/g at 293 K, respectively. Thermodynamic parameters such as Gibbs free energy (Delta G), enthalpy (Delta H) and entropy (Delta S) were calculated and the results indicated that the NOR or OFLX adsorption onto Fe/Cu oxides CPs was spontaneous and endothermic. Adsorption mechanism of NOR and OFLX may be involved a combination of electrostatic interaction, the formation of hydrogen bonds, pi-pi stacking interactions, surface complexation, hydrophobic interaction.

Mass production of nanomaterials to remove pollutants from water still faces many challenges, mainly due to the complexity of the synthesis methods involved and the use of dangerous reagents. The green method of preparation of nanomaterials from plants can effectively solve these problems. Fe,Cu oxide nanocomposites (Fe-Cu-NCs) were synthesized by a green and single-step method using loquat leaf extracts, and were used as an adsorbent for removal of Norfloxacin (NOR) and Ciprofloxacin (CIP) from aqueous solution. The synthesized adsorbent showed excellent adsorption properties for NOR and CIP. The experimental equilibrium data fitted the Redlich-Peterson and Koble-Corrigan models well and the maximum adsorption capacities of Fe-Cu-NCs calculated by the Langmuir model for NOR and CIP were 1.182 mmol/g and 1.103 mmol/g, respectively, at 293 K. Additionally, the morphologies and properties of Fe-Cu-NCs were characterized by transmission electron microscopy (TEM), scanning electron microscopy X-ray energy-dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis and the adsorption mechanism of NOR and CIP onto Fe-Cu-NCs was discussed. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. This study indicated that Fe-Cu-NCs are a potential adsorbent and provide a simple and convenient strategy for the purification of antibiotics-laden wastewater.

Background: As two important tumor markers, vascular endothelial growth factor (VEGF) and carcinoembryonic antigen (CEA) have a great value for clinical application in the early diagnosis of cancer. Due to the complex composition of biological samples, the results from combined detection of CEA and VEGF are often taken as a comprehensive indicator in order to make an accurate judgment on a disease. However, most of the current methods can only be used to detect the content of one biomarker. Therefore, it is necessary to explore a simple, rapid, low-cost, and highly sensitive method for the simultaneous detection of CEA and VEGF. Methods: Based on specific aptamers and magnetic separation, a time-resolved chemiluminescence enzyme-linked aptamer assay was developed for the simultaneous detections of CEA and VEGF in serum samples. Results: Under the optimal conditions, the linear range of the calibration curve for VEGF was from 0.5 to 80 ng mL(-1), and the limit of detection was 0.1 ng mL(-1). The linear range of the calibration curve for CEA was 0.5 to 160 ng mL(-1), and the limit of detection was 0.1 ng mL(-1). The established method was applied to detect VEGF and CEA in serum samples. The results were consistent with those of commercial kits. Conclusion: The method has high sensitivity and can quickly obtain accurate results, which could greatly improve the measurement efficiency, reduce the cost, and also reduce the volume of sample consumed. It can be seen that the method established in this study has important application value and broad application prospect in clinical diagnosis.

通过响应面试验优化超声辅助提取蔓菁多糖工艺,并对其体外抗氧化性进行研究.经过单因素试验考察液料比、提取温度、提取时间和超声功率对蔓菁多糖得率的影响,用Design-Expert 8.0.6软件进行四因素三水平的试验设计,并以多糖得率为响应指标进行响应面分析,得到蔓菁多糖的最佳提取条件.通过对羟基自由基(·OH)的清除能力来评价蔓菁多糖的抗氧化活性.结果 表明,蔓菁多糖的最优提取条件为:液料比44∶1 (mL/g)、提取温度57℃、提取时间56 min、超声功率为180W,在此条件下蔓菁多糖得率为65.43％,与预测值的相对误差为0.12％;蔓菁多糖对·OH的清除能力强于抗坏血酸,半抑制浓度(half inhibitory concentration,IC50)为0.415 mg/mL.故此优化试验有效可行且蔓菁多糖具有较强的抗氧化性.

预防医学专业本科生普遍存在专业认同感不强的问题,不利于我国公共卫生人才的培养和公共卫生事业的发展.本文通过对预防医学专业本科生进行专业认同状况的调查发现,大学入学前具有高度预防医学认同感的学生比例仅为18.1％,而完全不具有专业认同感的学生比例高达42.6％,这与预防医学第一志愿低填报率一致.影响预防医学专业认同感的主要因素包括就业前景、个人兴趣和社会评价.同时,专业认知度和专业认同感具有较强的相关性(相关系数为0.306,P<0.001).可见,提高学生的专业认知度是提升其专业认同感的关键.通过专题讲座、专业实践、科研引导、班主任和导师制度建设等多种专业认知教育途径,可以有效提高学生对预防医学的专业认知度和认同感.因此,健全预防医学的专业认知和认同教育,对助力学业发展、提高综合能力、制定职业规划具有重要的意义.

目的 了解许昌市农村饮水安全工程水质卫生状况,为农村饮水安全工程的改善和管理提供科学依据.方法 2015-2017年在供水量达到20 t/d以上的供水工程站设置监测点,在枯水期和丰水期进行水质监测,检测方法按照《生活饮用水标准检验方法》(GB/T 5750-2006)进行,按《生活饮用水卫生标准》(GB5749-2006)评价水质卫生状况.结果 2015-2017年共检测水样1 110份,合格964份,合格率86.85％.其中2015年检测292份,合格240份,合格率82.19％;2016年检测404份,合格355份,合格率87.87％;2017年检测414份,合格369份,合格率89.13％.水质合格率逐年增加,差异有统计学意义(x2=7.80,P＜0.05);丰水期和枯水期、不同县(市)供水水质合格率差异有统计学意义(x2=14.08,P＜0.05).三年所检测水样的不合格项目以总大肠茵群、茵落总数、耐热大肠菌群及浑浊度为主.结论 微生物超标是许昌市农村饮水安全工程存在的主要问题,需要进一步加强饮水安全工程建设和监督检测,提高水质卫生状况,确保居民饮水安全.

Self-assembly of building blocks for constructing multifunctional materials has opened prospects for sensing applications in the biomedical fields. In particular, the combination of aptamer with DNA assembly-based nanotechnology has greatly improved the performance of cancer cell detection. Nevertheless, the cancer cell detection strategies of integrating aptamer with protein are relatively sparse. So we have developed a self-assembled aptamer method to realize the efficient capture and rapid detection of cancer cells by ingeniously combining aptamer modified magnetic nanoparticles as capture nanoprobes with self-assembled aptamer/protein hybrid probes (SAPPs) as signal amplification probes. By merely mixing the component materials together simultaneously, the SAPPs, integrating aptamer for cancer cell recognition with protein for amplifying signal, were fabricated by DNA-governed one-step assembly. In addition, the SAPPs-based method exhibits efficient capture, rapid (about 45 min) and specific CCRF-CEM detection performance, with limits of detection down to 75 cells/mL in buffer and 200 cells/mL in whole blood.

目的:优化黑枸杞花青素的提取工艺,测定不同产地黑枸杞中花青素含量,为天然花青素的开发利用和功能研究提供理论基础.方法:采用超声辅助法提取黑枸杞中的花青素,在单因素实验的基础上,以花青素提取率为响应值,利用Design-Expert软件对提取条件进行响应面优化.采用pH示差法测定21种不同产地黑枸杞中花青素的含量.结果与结论:经优化,确定提取温度39℃,提取时间28 min,料(g)液(mL)比1:30,超声功率60％为花青素的最佳提取工艺.21种不同产地黑枸杞中花青素含量均较丰富,其中产自西藏山南和日喀则的黑枸杞中花青素的含量最高,甘肃的黑枸杞花青素含量较低,这可能与不同地区的土壤、气候条件不同有关.

Early detection of cancer is of great significance for disease prevention and diagnosis. However, the levels of most cancer markers are quite low in the early stages of disease, so it is urgent to develop a highly sensitive detection method. In this study, a label-free and highly sensitive colorimetric strategy was developed for the detection of the vascular endothelial growth factor(165) (VEGF(165)) in human serum. First, a convenient biosensor was constructed by immobilizing VEGF(165) on a microplate, where aptamers bound with VEGF(165) to form a complex. Then, streptavidin labeled-horseradish peroxidase (HRP-SA) combined with the complex via the interaction between streptavidin and biotin, thus catalyzing the 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 system to produce colored products. In the presence of target, immobilized VEGF(165) and target competitively bound with the aptamers, resulting in a reduction of the colorimetric signal. Moreover, the optical density (OD) signal decreased with the increase of target concentration. The strategy showed a broad linear range (0.1-100 ng/mL) and a rather low detection limit of 10 pg/mL with good precision and selectivity. Further, the proposed method was successfully applied in detecting VEGF(165) in human serum. The detection results of serum samples showed that the proposed assay had a high correlation with CLEIA kits (r = 0.971, p = 0.001). It has potential for application in clinical research and diagnosis. (C) 2019 Elsevier B.V. All rights reserved.

Mononuclear macrophages are important immune cells in the organisms. The complicated membrane structure underlying the diverse functions of mononuclear-macrophage has been largely unresolved. As a representative of monocyte-derived macrophages, the membrane structure of PMA differentiated THP-1 cells was comprehensively investigated by AFM-based single molecule approaches. The rugged ectoplasmic side of mononuclear-macrophage membrane are significantly different from erythrocytes and mammalian somatic cell membranes. But the smooth lipid bilayer and the branched lipid raft domains obtained by proteinase K and MβCD treatment of the protein-covered cytoplasmic side, are common characteristics among all the studied cell membranes. This discovery of distinct organization of membrane proteins on both sides of mononuclear-macrophage membranes provides additional evidence for the asymmetry of membrane structure. The podosome-associated structures of mononuclear-macrophage were directly examined, and the independent localization of podosome domains and the lipid rafts was verified by in situ AFM, giving new insight into this multifunctional organelle.

pH玻璃电极对溶液中H+的选择性响应,关键在于其敏感膜中膜电位的形成.因此准确理解膜电位形成的思维逻辑非常必要,该思维逻辑就是模型思维与函数思维的联合运用.鉴于此,本文阐述了膜电位形成所采纳的模型及其计算公式推导,并对pH玻璃电极发展趋势进行了讨论.