Combinatorial Therapeutic Effect of Inhibitors of Aldehyde Dehydrogenase and Mitochondrial Complex I,and the Chemotherapeutic Drug,Temozolomide against Glioblastoma Tumorspheres

Resident cancer cells with stem cell-like features induce drug tolerance, facilitating survival of glioblastoma (GBM). We previously showed that strategies targeting tumor bioenergetics present a novel emerging avenue for treatment of GBM. The objective of this study was to enhance the therapeutic effects of dual inhibition of tumor bioenergetics by combination of gossypol, an aldehyde dehydrogenase inhibitor, and phenformin, a biguanide compound that depletes oxidative phosphorylation, with the chemotherapeutic drug, temozolomide (TMZ), to block proliferation, stemness, and invasiveness of GBM tumorspheres (TSs). Combination therapy with gossypol, phenformin, and TMZ induced a significant reduction in ATP levels, cell viability, stemness, and invasiveness compared to TMZ monotherapy and dual therapy with gossypol and phenformin. Analysis of differentially expressed genes revealed up-regulation of genes involved in programmed cell death, autophagy, and protein metabolism and down-regulation of those associated with cell metabolism, cycle, and adhesion. Combination of TMZ with dual inhibitors of tumor bioenergetics may, therefore, present an effective strategy against GBM by enhancing therapeutic effects through multiple mechanisms of action.     

5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯双波长叠加分光光度法同时测定铑和钯

以5-(5-碘-2-吡啶偶氮)-5-二氨基甲苯(5-I-PADAT)作显色剂,建立了双波长叠加分光光度法同时测定铑、钯的新方法。研究发现,在0.6～1.8 mol/LHCIO4介质中,Pd(II)与5-I-PADAT形成稳定络合物,而在此酸度下,Rh(III)则完全不能反应;在pH4.0～5.2 HAc-NaAc缓冲介质中,Rh(III)与5-I-PADAT可形成稳定紫红色络合物,铑络合物形成后提高酸度至0.24～5.57 mol/L HCIO4介质,该络合物不仅不被分解,而且转化为另一种紫蓝色质子化型体,吸收红移、吸光度显著增大。研究还发现,Rh(III)、Pd(II)与5-I-PADAT形成的络合物,均呈现两个吸收峰,强峰分别位于580 nm和584 nm处,弱峰分别位于538 nm和547 nm处。其各自的强弱峰对应的吸光度之和与溶液中铑、钯的含量具有良好的线性关系。据此,建立了双波长叠加分光光度法同时测得铑、钯新方法。铑和钯的表观摩尔吸光系数分别为εRh=2.76×105L.mol-1.cm-1和εPd=1.14×105L.mol-1.cm-1,灵敏度分别为单波长法测定的1.52倍和1.53倍。铑、钯的质量浓度分别在0～0.5μg/mL和0～1.0μg/mL范围内符合比尔定律。方法用于催化剂中铑和钯的同时测定,结果满意。     

聚乳酸星形与树枝状共聚物的研究进展

就近年来研究者比较关注的非线形结构乳酸共聚物进行了综述,阐述了非线形结构聚合物的特点和优势,并重点介绍了星形和树枝状乳酸共聚物合成及应用中的研究进展.     

Computational investigation on 2,6-diamino-3,5-dinitropyridine-1-oxide crystal

Density functional theory calculations were performed on crystalline 2,6-diamino-3,5-dinitropyridine-1-oxide (ANPyO). The conduct bands are generally quite flat, while the valence bands are uneven. The carbon, oxygen and amino nitrogen atoms make up the narrow lower energy levels. While the carbon, amino nitrogen and atoms in nitro group make up the higher energy levels. Change of electronic charges for the decrease of the cell edge a and c are almost the same, but different from the decrease of the cell edge b, indicating an anisotropic effect related to compressions. The C-Nitro and the N–O (N-oxide) bonds are the weakest, and tend to rupture upon external stimulation. The Mulliken population for the N–O (N-oxide) bond in crystal is much smaller than that in molecule, indicating that the molecular packing weakens this bond. Judged by the fact of N–O (N-oxide) bond being weaker than C-Nitro bond, ANPyO is sensitive to mechanic impact than 1,3,5-triamino-2,4,6-trinitrobenzene, which is in good agreement with experiment. The crystal lattice energy is predicted to be −166.03 kJ/mol, after being corrected for basis set superposition error.     

Atomic layer deposition of TiO2 nanotubes and its improved electrostatic capacitance

Titanium dioxide (TiO₂) nanotubes are fabricated into anodic aluminum oxide (AAO) membrane via atomic layer deposition (ALD). For the ALD of TiO₂, gaseous precursors, titanium (IV) isopropoxide and water are sequentially applied and chemically reacted with each other. A thickness of nanotubes is precisely controlled by the applied cycle numbers of ALD and the morphology of nanostructures is investigated by SEM and TEM. The amorphous property of TiO₂ nanostructures is revealed by XRD and the composition of nanotubes is measured by TEM–EDX. The impurity contents and binding structure of the nanostructures are analyzed by XPS. The electrostatic capacitance of TiO₂ nanotubes into AAO is 480 μF/cm² and it is about 3 times higher compared with AAO membrane (172 μF/cm²).     

关于矩阵的复符号模式类的行列式值域的一个猜想

研究矩阵的复符号模式类的行列式值域是与复符号非异阵的刻画有关的一个问题.文中部分解决了邵嘉裕先生等人提出的一个猜想.     

测定金属电阻温度系数的方法研究

从金属电阻率与温度的线性关系出发,设计了测定金属电阻温度系数的实验方案。利用基本的电磁学仪器和热学仪器组合进行实验,以漆包铜线作为待测金属丝测定出铜的电阻温度系数,分析了导致系统误差产生的主要原因,并就待测金属丝的选取原则、温度控制的方法进行了讨论。     

Highly Efficient Oxidative Bromination of Alkanes with the HBr-H2O2 System in the Presence of Catalyst

Various cycloalkanes and straight‐chain alkanes were efficiently brominated with an aqueous HBr‐H₂O₂ system. This oxidative brominating process was promoted by catalysis and irradiation with light. The cycloalkanes were converted to the corresponding bromo‐cycloalkanes in moderate yields and the straight‐chain alkanes produced dominantly secondary bromides. This simple but effective bromination method of alkanes is characterized by high atom efficiency, inexpensive reagents and the absence of organic waste, which make it a good alternative to the existing method for C? H activation through bromination.     

Progress in DNA Aptamers as Recognition Components for Protein Functional Regulation

Proteins play a central role in all domains of life, and precise regulation of their activity is essential for understanding the related biological processes and therapeutic functions. Nucleic acid aptamers, the molecular recognition components derived from systematic evolution of ligands by exponential enrichment(SELEX), can specifically identify proteins with antibody-like recognition characteristics and help to regulate their activity. This minireview covers the SELEX-based selection of protein-binding aptamers, membrane protein analytical techniques based on aptamer-mediated target recognition, aptamer-mediated functional regulation of proteins, including membrane receptors and non-membrane proteins(thrombin as a model), as well as the potential challenges and prospects regarding aptamer-mediated protein manipulation, aiming to supply some useful information for researchers in this field.