A label-free amperometric immunosensor based on horseradish peroxidase functionalized carbon nanotubes and bilayer gold nanoparticles

In this work, a novel label-free amperometric immunosensor has been constructed for detecting α-1-fetoprotein (AFP) based on nanocomposite of horseradish peroxidase (HRP) labeled carbon nanotubes (CNTs). First, the gold nanoparticles (AuNPs) were electrodeposited on the surface of the glass carbon electrode by electrochemical reduction of gold chloride tetrahydrate (HAuCl₄) to immobilize horseradish peroxidase labeled carbon nanotubes (HRP-CNTs). Then HRP-CNTs bioconjugate was immobilized on the surface of the electrodeposited AuNPs layer by the combination of forces (coordination and electrostatic force). Subsequently, it was immersed into gold colloidal nanoparticles (GNPs) solution, which was used to immobilize antibody biomolecules (anti-AFP). Enhanced sensitivity was obtained by using bioconjugates featuring HRP labeled (HRP-CNTs), which had lager specific surface area and good electronic catalysis (current response signal) compared to carbon nanotubes. Under optimized conditions, the linear ranges were from 0.2 to 200 ng mL⁻¹ with a detection limit of 0.067 ng mL⁻¹ (at an S/N of 3). The proposed immunosenor showed good precision, acceptable stability and reproducibility and could be used for the detection AFP in normal human serum, which provided a potential alternative tool for the detection of protein in clinical diagnosis.     

Detection of colorectal adenoma and cancer based on transthyretin and C3a-desArg serum levels

Colorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.     

不同品系北京鸭血清前白蛋白多态性的研究

应用聚丙烯酰胺凝胶电泳法研究了北京鸭的血清前白蛋多态性,在2个位点观察到多态,Pam位点为单态,在Pas位点发现有5种表现型,它们的频率是：Pas2-2O 26．67％,Pas1-2为12％,Pas2-1为45.33%,Pas1-1为2．67％,Pas2-0为13．33％,在Paf位点发现有4种表现型,它们的频率是：PafF为29．33％,PafS为41．33％,PafFS为10．67％,Paf0为18．67％,并计算了它们的基因频率,群体平均杂合度和遗传距离,遗传分析表明,樱桃谷鸭和奥白星鸭遗传结构相似,而与B系北京鸭遗传结构有明显差异。     

抗狂犬病血清致过敏反应及血清病的探讨

128例犬咬伤患者注射抗狂犬病血清后,过敏反应发生率为3.91％(5/128);血清病发生率为11.72％(15/128)。过敏反应的主要症状为头晕、恶心、面色苍白;血清病的主要症状为局部及周身荨麻疹、表浅淋巴结肿大、恶心、食欲不振等。血清病有明显的年龄特点,0～19岁儿童和青少年发生率为4.0％,20岁以上成年人为13.59％,二者差异显著。     

糖-蛋白质饮料对男力量运动员一次抗阻运动后部分血清指标的影响

为探讨糖-蛋白质补充对一次性抗阻运动恢复过程的影响.文中以18名男子力量项目运动员在一次抗阻运动前、运动中和运动后,分别摄入糖-高蛋白饮料(HP组=6人,糖:蛋白质=3∶1)、糖-低蛋白饮料(LP组=6人,糖∶蛋白质=6∶1)或纯糖对照饮料(C组=6人).在运动前、运动后即刻、运动后3h和运动后次日晨采集血样,测定血清肌酸激酶(CK)、天门冬氨酸转移酶(AST)、谷丙氨酸转移酶(ALT)、尿素(BU)以及睾酮(T)和皮质醇(Cor).研究结果表明:运动后3h和运动后次日晨C组CK水平显非常著高于HP组和LP组(P0.01,分别),运动后次日晨LP组CK水平显著高于HP组(P0.05);运动后3hC组ALT水平显著高于HP组和LP组(P0.05,分别);运动后即刻C组Cor水平显著低于HP组和LP组(P0.05,分别);各时间点T、AST及BU水平组间比较无差异性.摄入糖-蛋白质饮料能促进男性力量项目运动员抗阻运动后机体运动能力的恢复和提高.摄入糖-高比例蛋白质更有利于运动后疲劳的恢复和机体运动能力的提高.     

压电式传感器测定蛋白质吸附动力学参数

利用液隔电极型压电式传感器实时监测牛血清白蛋白(BSA)在石英表面吸附过程。基于所提出的吸附动力学模型,估算出BSA在石英表面的吸附速率常数为ka=1.27×103mol-1·L·s-1,脱附速率常数为kd=1.31×10-3s-1,由可逆吸附态向不可逆吸附态的转化速率常数为kf=3.46×10-4s-1。     

小麦蛋白质酸性聚丙烯酰胺凝胶电泳方法研究

研究了缓冲液种类、离子强度、慢离子浓度、缓冲液ｐＨ、凝胶浓度等因素对小麦蛋白质ＰＡＧＥ分离效果的影响，采用Ｌ１６（４１×２１２）正交表进行条件的优化。所建立的小麦蛋白质柠檬酸盐ＰＡＧＥ方法，具有分辨效率高、稳定的特点。可通过改变胶浓度实现醇溶蛋白全组分和小麦清蛋白、球蛋白的分离研究。同时，不同的小麦品种间各类蛋白所表现出的差异大，因而，此法也可用于小麦品种鉴定和遗传研究。     

磁场对大鼠血清营养相关生化指标的影响

报道了旋转恒定磁场对大鼠血液生化指标的影响.在强度为0 4T,旋转速率为8Hz的磁场条件下,鼠龄3周的大鼠,磁场每天处理2h,共持续10周,导致血清葡萄糖水平显著下降;鼠龄为10周的大鼠,每天磁场处理2h,共持续4周,则引起血清甘油三酯水平的显著降低,血清高密度脂蛋白水平则显著上升.     

豆浆污染管式膜清洗系统的实验研究

开发海绵橡胶球(固)-水(液)两相清洗系统，用于豆浆污染的管式膜的清洗．通过海绵橡胶球清洗与传统大量水冲清洗方法对水通量恢复率和蛋清截留率的比较，确认了前者具有良好的清洗效果．前者恢复率比后者高约10％，蛋清截留率基本不受影响，对膜孔径无明显影响．     

Electroseparation of an antibacterial peptide fraction from snow crab by-products hydrolysate by electrodialysis with ultrafiltration membranes

Recently, a snow crab by-products hydrolysate has demonstrated antibacterial properties due to a peptide with a molecular weight of about 800 Da, but only at high concentration. Consequently, peptide hydrolysate has been fractionated to obtain peptides in a more purified form. The aim of this work was to separate a snow crab by-products hydrolysate by electrodialysis with ultrafiltration membranes (EDUF). EDUF, which allows separation of molecules according to their charges and molecular weights, was used to recover and concentrate the active antibacterial fraction. Two different ultrafiltration membranes (20 and 50 kDa) and two electrical field strengths (2 and 14 V/cm) were used as separation parameters. After EDUF separation, the 300-600 Da peptide molecular weight range was the most recovered with an abundance of 94%. Moreover, fractionation at 14 V/cm with ultrafiltration membranes of 50 kDa allowed the recovery of an anionic fraction which showed antibacterial properties on Escherichia coli ATCC 25922 and Listeria innocua HPB 13.