Gold nanoparticle-labeled detection antibodies for use in an enhanced electrochemical immunoassay of hepatitis B surface antigen in human serum

The application of gold nanoparticle-based electrochemical immunoassays have been extensively studied for the detection of hepatitis B surface antigen (HBsAg), but most often they exhibit low sensitivity. We describe the fabrication of a new electrochemical immunoassay for signal amplification of the antigen-antibody reaction combined with the nanogold-based bio-barcode technique. Hepatitis B surface antibody (HBsAb) was initially immobilized on a nanogold/thionine/DNA-modified gold electrode, and then a sandwich-type immunoassay format was employed for the detection of HBsAg using nanogold-codified horseradish peroxidase-HBsAb conjugates as secondary antibodies. Under optimal conditions, the current response of the sandwich-type immunocomplex relative to the H₂O₂ system was proportional to HBsAg concentration in the range from 0.5 to 650 ng·mL^?1 with a detection limit of 0.1 ng·mL^?1 (S/N?=?3). The precision, reproducibility and stability of the immunosensor were acceptable. Subsequently, the immunosensors were used to assay HBsAg in human serum specimens. Analytical results were in agreement with those obtained by the standard chemiluminescence enzyme-linked immunosorbent assay.     

CO预处理对CuO/γ-Al2O3催化剂性能的影响

采用XRD，TPR，CO吸附in-situ IR，CO氧化反应等对CuO/γ-Al₂O₃催化剂经CO处理前后的结构、组成和催化性能进行了研究。结果表明，经CO在250 ℃下处理1 h后CuO/γ-Al₂O₃催化剂中出现了分散态Cu⁺物种，该物种的产生使催化剂的活性明显提高。     

Synthesis and anticancer activities of porphyrin induced anticancer drugs

In view of the property of porphyrin's accumulation selectively in tumor,the ftorafur was modified by binding a porphyrin block to improve its tumor targeting and reduce its side effects.These novel porphyrin derivatives and metal compounds were synthesized under mild conditions with satisfactory yield,and the constructions of all these new compounds were characterized by UV,IR,MS, ~1H NMR spectra and elementary analysis.Their anticancer activities were evaluated by MTT assay;the results indicated that the anticancer activities of compounds 4a-c were twice as high as that of ftorafur.     

间接法测定吴茱萸碱磷脂复合物的复合率

建立吴茱萸碱磷脂复合物复合率的测定方法。采用紫外分光光度法测定游离的吴茱萸碱的含量,从而计算吴茱萸碱磷脂复合物的复合率。结果表明,吴茱萸碱在225nm处有最大吸收,浓度在1.05—4.20μg.mL-1范围内与吸光度呈良好的线性关系,回归方程为：A=0.1776C＋0.006,r=0.9997;平均加标回收率为99.71%,RSD为1.26%（n=9）。该法操作简便、精密度好、结果准确可靠。     

Analysis of dynamical buckling and post buckling for beams by finite segment method

IntroductionThe stability or dynamical buckling of structures is the parametrically exacted vibration ofstructures,and itis a nonlinear vibration problem[1].Dynamical stabilityof beams was studiedusing Galerkin variation method by Russian scholar,and B.B.…