Comparison of time-resolved fluoroimmunoassay for determining hexoestrol residues in chicken muscle tissues based on polyclonal antibodies with liquid chromatography and tandem mass spectrometry

A time-resolved fluoroimmunoassay (TR-FIA) was developed for the determination of hexoestrol (HES) residues in animal tissues. The limit of detection (LOD) was determined to be 0.02 ng g(-1) and the limit of quantification (LOQ) was less than 0.12 ng g(-1). The results obtained by the TR-FIA and ELISA showed a good correlation. The established TR-FIA was validated for the determination of market chicken muscle tissues and confirmed by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). This proposed technique could be applied to routine residue analysis.     

Sales effort free riding and coordination with price match and channel rebate

This paper studies sales effort coordination for a supply chain with one manufacturer and two retail channels, where an online retailer offers a lower price and free-rides a brick-and-mortar retailer’s sales effort. The free riding effect reduces brick-and-mortar retailer’s desired effort level, and thus hurts the manufacturer’s profit and the overall supply chain performance. To achieve sales effort coordination, we designed a contract with price match and selective compensation rebate. We also examined other contracts, including the target rebate contract and the wholesale price discount contract, both with price match. The numerical analysis shows that the selective rebate outperforms other contracts in coordinating the brick-and-mortar retailer’s sales effort and improving supply chain efficiency.     

水相中一锅煮、四组份反应高效合成多取代嘧啶类化合物

此文报道了一种室温下,水相中由丙二睛,二硫化碳,卤代烃和烷基异硫脲四组份、一锅煮反应合成多取代嘧啶类化合物的方法。该方法具有高效、反应条件温和、操作简单、适用范围广和环境友好等优点。     

Time-resolved fluoroimmunoassay for 19-nortestosterone residues in aquaculture tissues.

A competitive time-resolved fluoroimmunoassay (TR-FIA) was developed for the determination of 19-nortestosterone (17beta-NT) residues in aquaculture tissues. The limit of detection (LOD) was determined to be 0.08 ng g-1 and the limit of quantification (LOQ) was less than 0.8 ng g-1. The results obtained by the TR-FIA and ELISA showed a good correlation. The established TR-FIA was validated for the determination of incurred aquaculture tissues and confirmed by liquid chromatography tandem mass spectrometry (LC/MS/MS). This proposed technique could be applied to routine residue analysis.     

Co(Ⅲ)官能化SBA-15的制备、表征及其催化环己烯环氧化

通过环戊二烯基修饰的SBA-15(SBA-15-Cp)与马来酸酐的Diels-Alder反应及水解合成了邻二羧酸官能化的SBA-15,并将原位生成的Co(Ⅲ)络合物负载于其上制得Co(Ⅲ)官能化SBA-15样品SBA-15-Co(Ⅲ).傅里叶变换红外光谱、元素分析和X射线光电子能谱法结果证实羧酸官能团和Co(Ⅲ)成功地...     

αGal抗原决定簇的立体选择性合成研究

αGal抗原决定簇二糖具有重要的生物学功能。以α-半乳糖甲苷为原料,经多步反应立体选择性地合成了Gal(α1→3)Gal(α—OCH3),并以^1H NMR、^13C NMR及MALDI—TOF—MS等对关键中间体及终产物进行了表征。比较了硫苷法、溴代糖法和三氯乙酸酯法构建糖苷键反应的结果,表明采用三氯乙酸酯法合成寡糖,具有反应条件温和、收率高和立体选择性好的特点。     

胆囊癌中PTEN基因异常表达及甲基化的研究

目的 探讨胆囊癌的发生、发展及转移与PTEN 基因异常表达及其基因启动子区异常甲基化的关系。方法 选取胆囊癌标本44 例（胆囊癌组）和胆囊炎标本20 例（对照组）,通过免疫组织化学染色、Western-blot、甲基化特异性PCR法分析两组患者胆囊组织中PTEN 基因表达及启动子区甲基化差异。结果 与对照组相比,胆囊癌组中PTEN 基因表达阳性率明显下降（P＜0.01）,而启动子区甲基化阳性率显著增高（P＜0.01）;胆囊癌组中有淋巴结转移者PTEN 基因表达阳性率较无淋巴结转移者降低（P＜0.05）,而启动子区甲基化阳性率增高（P＜0.05）;胆囊癌分期增高,PTEN 基因表达阳性率降低（P＜0.05）,而启动子区甲基化阳性率增高（P＜0.05）。结论 PTEN 基因低表达是胆囊癌的发生、发展及转移的重要原因之一,其低表达与启动子区过度甲基化有关。     

用冲击法测试桩静承载力的数值讨论

本文在总结桩静承载力的动测法和数值分析方法的基础上,用一维离散多质点体系来模拟桩-土相互作用,数值仿真用微小应变冲击法测试单桩静承载力的动测过程,并进行了数值讨论,指出了此法及其它简易动测法中所存在的问题提出了初步改进建议。