碳阳极的氧化性能研究

采用效失重法系统地测定了铝用碳阳极添加硼酸、三氟化铝后在空气中的氧化反应速度常数,结果表明硼酸、三氯化铝的含量在0．5％～2．0％范围内,碳阳极的抗氧化能力有所增强．     

建筑物电气设备谐波故障的防止对策

叙述了谐波电流、电压对公用电网用户电气设备－－电力电容器、电抗器、电力变压器、电缆线路和低压开关设备的危害,并提出了这些电器设备降低谐波故障的措施。     

Al-Mg合金热力学性质的计算

以Ｍｉｅｄｅｍａ二元合金生成热模型为基础,结合一些基本热力学关系式,利用元素的基本性质计算了１０７３Ｋ下ＡｌＭｇ合金中组元Ｍｇ的活度及合金的部分热力学函数（ΔＨ,ＧＥ,ＳＥ）。结果表明,在１０７３Ｋ下,溶液中Ｍｇ的行为相对拉乌尔定律存在较大的负偏差;混合焓、过剩自由能与过剩熵在整个浓度范围内均为负值;混合焓最小值为－１１．４ｋＪ／ｍｏｌ,过剩自由能最小值为－８．７７ｋＪ／ｍｏｌ,过剩熵的绝对值较小,接近零。计算结果与实验数据吻合较好。     

Histone Deacetylase-Triggered Self-Immolative Peptide-Cytotoxins for Cancer-Selective Drug Delivery

Precise delivery and release of therapeutics in the subcellular targets are critical for tumor-selective chemotherapy. Self-immolative structures are sophisticatedly designed to achieve stimuli-responsive drug delivery. Herein, the facile fabrication of self-immolative peptide-camptothecin (CPT) nanoassemblies is reported for cancer-selective drug delivery by utilizing the dual-mode peptide targeting design and amine-catalyzed intramolecular hydrolysis. The dual-mode peptide targeting design is realized by co-assembly of tumor targeting and nuclei-localizing peptide-CPT prodrugs, rendering the nanoassemblies with efficient cancer cell-selective capability. When the nanoassemblies enter cancer cell, the overexpressed endonuclear histone deacetylases (HDACs) cleave the acetyl group to generate primary amines, triggers amine-catalyzed intramolecular hydrolysis, and fast-release drug in the cell nuclei. The peptide-CPT prodrugs release up to 68% CPT in 1 h in the presence of HDACs, while no detectable CPT release is observed in the absence of HDACs at the same time. The peptide-CPT prodrugs selectively kill cancer cells with high HDACs levels. The dual targeting peptide-CPT nanoassemblies exhibit extended blood circulation, excellent tumor accumulation, and potent antitumor activity by inhibiting tumor progression and metastasis in mice bearing 4T1 aggressive breast tumors. Overall, the HDAC-triggered self-immolative strategy is promising for developing cancer-selective drug delivery systems.     

Screening of Zwitterionic Liposomes with Red Blood Cell-Hitchhiking and Tumor Cell-Active Transporting Capability for Efficient Tumor Entrance

The active transport of nanoparticles into the solid tumor through cell transcytosis has shown great promise in cancer nanomedicine, but it is challenging to develop efficient active transporting nanomedicines with the potential for clinical translation. Here, a type of tertiary amine oxide (TAO)-containing zwitterionic liposomal nanocarriers is developed that can hitchhike red blood cells (RBCs) to tumor blood vessels and enter solid tumors through transcytosis. To boost the active-transporting capability, a library of the TAO liposomes (TAOLs) with different chemical structures and particle sizes is constructed and screened by their stability and active transporting capability. Two types of TAOLs are identified that can induce efficient tumor cell transcytosis through rapid macropinocytosis and endoplasmic reticulum/Golgi-involved exocytosis. It is found that these zwitterionic TAOLs can hitchhike RBCs to gain long blood circulation, get off the cell at the tumor site, effectively enter the tumor through transcytosis, and infiltrate the whole tumor. The chemotherapeutic drug-loaded liposomes can stop the tumor progression of mice bearing human hepatocellular carcinoma HepG2 cells, exhibiting superior antitumor activity compared to the traditional liposomal drug. This study demonstrates a strategy to construct effective active transporting liposomal nanomedicines for efficient tumor entrance.     

随机扩增多态性DNA分子标记技术在肠球菌分型中的应用

该研究旨在探索随机扩增多态性DNA（Random Amplified Polymorphic DNA，RAPD）分子标记技术在肠球菌种间快速分型的效果。试验通过筛选模板、单引物、双引物及RAPD反应体系，构建肠球菌种间分型体系，对32株已知肠球菌分型确定分型相似度标准，并通过对46株未知肠球菌进行种间分型以及管家基因rpoA测定验证分型效果。结果显示微波法提取基因组DNA满足实验需要，筛选出7条单引物用于双引物配对组合，最适的双引物反应体系为：2×PCR Taq Mix 12.5 μL，模板DNA 1 μL，引物各1 μL，ddH2O 9.5 μL；分型效果最好的双引物组合为Primer1+Primer5，该引物组合可以在80%的相似度下区分肠球菌种间差异，Primer1+Primer3组合在500 bp位置扩增出海氏肠球菌的特征条带，可以作为海氏肠球菌的鉴定指标，用以快速鉴定海氏肠球菌。