广义正交码索引调制系统的性能分析

摘 要：为了提高码索引调制（code index modulation，CIM）系统的传输效率，提出了一种具有更低复杂度的单输入单输出（single input single output，SISO）的广义正交码索引调制（generalized orthogonal code index modulation，GQCIM）系统。CIM 系统使用扩频码和星座符号传输信息，但只能激活两个扩频码索引和一个调制符号。而 GQCIM 系统以一种新颖的方式克服了只激活一个调制符号的限制，同时充分利用了调制符号的正交性，增加扩频码索引以传输更多的额外信息位，提高了系统的传输效率。此外，分析了GQCIM系统的理论性能，推导了误码率性能的上界。通过蒙特卡罗仿真验证了GQCIM系统的性能，对比发现GQCIM系统的理论和仿真性能一致。而且在相同的传输效率下，结果显示GQCIM系统的性能优于同样具有正交性的调制系统，如广义码索引调制（generalized code index modulation，GCIM）系统、CIM系统、码索引调制-正交空间调制（code index modulation aided quadrature spatial modulation，CIM-QSM）系统、码索引调制-正交空间调制（code index modulation aided spatial modulation，CIM-SM）系统、脉冲索引调制（pulse index modulation，PIM）系统。     

Effect of microwave heating time on the gel properties of chicken myofibrillar proteins and their formation mechanism

The present work was conducted to illustrate the mechanism of gel formation of myofibrillar proteins (MPs) under different microwave heating times. The results showed that the denaturation enthalpy (ΔH) of the MPs significantly decreased when the heating time increased from 3 to 9 s and then completely disappeared as the heating time progressed, indicating that the MPs gradually denatured and subsequently aggregated with increasing heating time, which was further verified by the changes in the secondary structure, electrophoretic bands, and gel properties (e.g., water holding capacity and textural profiles) of the MPs. Microstructural images indicated that the MP gel formed under 12 s had the most compact network, indicating that extended microwave heating time could induce quality deterioration of MP gels. Moreover, the hydrophobic forces, electrostatic forces, and disulphide bonds of the MPs gradually intensified with increasing microwave heating time, suggesting that both non-covalent and covalent bonds could promote molecular denaturation and subsequent aggregation of MPs. In addition, correlation analysis revealed that the changes in the molecular conformation of MPs induced by different microwave heating times could effectively regulate the formation of MP gels and their related properties.     

Evaluation of the PSMA-Binding Ligand 212Pb-NG001 in Multicellular Tumour Spheroid and Mouse Models of Prostate Cancer

Radioligand therapy targeting the prostate-specific membrane antigen (PSMA) is rapidly evolving as a promising treatment for metastatic castration-resistant prostate cancer. The PSMA-targeting ligand p-SCN-Bn-TCMC-PSMA (NG001) labelled with ²¹²Pb efficiently targets PSMA-positive cells in vitro and in vivo. The aim of this preclinical study was to evaluate the therapeutic potential of ²¹²Pb-NG001 in multicellular tumour spheroid and mouse models of prostate cancer. The cytotoxic effect of ²¹²Pb-NG001 was tested in human prostate C4-2 spheroids. Biodistribution at various time points and therapeutic effects of different activities of the radioligand were investigated in male athymic nude mice bearing C4-2 tumours, while long-term toxicity was studied in immunocompetent BALB/c mice. The radioligand induced a selective cytotoxic effect in spheroids at activity concentrations of 3–10 kBq/mL. In mice, the radioligand accumulated rapidly in tumours and was retained over 24 h, while it rapidly cleared from nontargeted tissues. Treatment with 0.25, 0.30 or 0.40 MBq of ²¹²Pb-NG001 significantly inhibited tumour growth and improved median survival with therapeutic indexes of 1.5, 2.3 and 2.7, respectively. In BALB/c mice, no signs of long-term radiation toxicity were observed at activities of 0.05 and 0.33 MBq. The obtained results warrant clinical studies to evaluate the biodistribution, therapeutic efficacy and toxicity of ²¹²Pb-NG001.     

淀粉预糊化温度对肉粉肠品质特性的影响和机制研究

绿豆淀粉的预糊化是肉粉肠区别于其他熏煮香肠的关键加工工艺，因此，预糊化淀粉的温度对产品的品质至关重要。本研究将绿豆淀粉分别用75、85、95 ℃的热水进行预糊化后制备肉粉肠，探讨不同的预糊化温度对产品品质和淀粉糊化度（Degree of Starch Gelatinization，DSG）的影响。实验结果表明，随着预糊化淀粉温度的升高，肉粉肠的DSG和乳化稳定性显著增加（P<0.05），蒸煮损失显著降低（P<0.05），且大量自由水向不易流动水转变。同时，随预糊化淀粉温度的增加，肉粉肠的硬度、回复性、弹性、脆性、咀嚼性、致密性和亮度值（Lightness，L*）均显著增加（P<0.05），促进产品最终品质的形成。总体可接受评分在95 ℃的预糊化温度时达到最高（P<0.05）。此外，聚类分析（Hierarchical Cluster Analysis，HCA）结果表明，95 ℃的预糊化温度对肉粉肠的品质特性有上调的影响。综上所述，95 ℃是提高肉粉肠品质的最佳预糊化淀粉温度。     

天然油脂乙氧基化物稳定高内相乳液影响因素的研究

以棕榈仁油乙氧基化物(SOE-N-60)为表面活性剂稳定高内相乳液(HIPEs)。通过对乳液外观、微观结构、粒径分布、黏度和流变学测试，研究了油相体积分数、SOE-N-60添加量对HIPEs性能的影响，同时对其稳定性进行考察。结果表明：SOE-N-60添加量为0.6%~1.5%（油相体积分数为83%）、油相体积分数为74%~86%（SOE-N-60添加量为1.0%）时可形成稳定的HIPEs，此时乳液液滴内部形成紧密堆积的网络结构，乳液粒径变小，具有弹性凝胶性质，并展现出很好的黏弹性和触变性，且随着油相体积分数和SOE-N-60添加量的增大，乳液黏弹性逐渐增强，同时HIPEs在(-5±1) ℃、(25±1) ℃、(40±1) ℃下贮存24 h时均具有良好的稳定性。