Interaction of a New Fluorescent Probe with DNA and its Use in Determination of DNA

In this paper we reported a metal complex 1-Zn (2,5-di-[2-(3,5-bis(2-pyridylmethyl)amine-4-hydroxy-phenyl)-ethylene]-pyrazine-Zn) as a fluorescent probe sensing DNA. The result of the competitive experiment of the probe with ethidium bromide (EB) to bind DNA, absorption spectral change and polarization change in the presence and absence of DNA revealed that interaction between the probe and DNA was via intercalation. Ionic strength experiment showed the existence of electrostatic interaction as well. Scatchard plots also confirmed the combined binding modes. The fluorescence enhancement of the probe was ascribed to highly hydrophobic environment when it bound the macromolecules such as DNA, RNA or denatured DNA. The binding constant between the probe and DNA was estimated as 3.13 × 10⁷ mol⁻¹ L. The emission intensity increase was proportional to the concentration of DNA. Based on this, the probe was used to determine the concentration of calf thymus DNA (ct-DNA). The corresponding linear response ranged from 2.50 × 10⁻⁷ to 4.75 × 10⁻⁶ mol L⁻¹, and detection limit was 1.93 × 10⁻⁸ mol L⁻¹ for ct-DNA.     

Novel Synthesis and Crystal Structure of 2-(4-Methylphenyl)-3-ferrocenyl-4,4-dicyanpyrrolizidine

A novel ferroenyl pyrrolizidine derivative containing cyano groups, 2-(4-methylphenyl)-3-ferrocenyl-4,4-dicyanpyrrolizidine (C26H25FeN3 , Mr=435.34), was synthesized in moderate yields via a facile 1.3-dipolar cycloaddition in refluxing toluene and its crystal structure was determined by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a=10.3792(10), b=11.4485(11), c=19.1243(15), β=109.496(4)°, V=2142.2(3)3, Dc=1.350 g/cm3, μ(MoKα)=0.721 mm-1 , Z=4, T=113(2)K, F(000)=912, the final R=0.0586 and wR=0.1664.     

Surface plasmon enhanced photoluminescence in amorphous silicon carbide films by adjusting Ag island film sizes

Ag island films with different sizes are deposited on hydrogenated amorphous silicon carbide (α-SiC:H) films, and the influences of Ag island films on the optical properties of the α-SiC:H films are investigated. Atomic force microscope images show that Ag nanoislands are formed after Ag coating, and the size of the Ag islands increases with increasing Ag deposition time. The extinction spectra indicate that two resonance absorption peaks which correspond to out-of-plane and in-plane surface plasmon modes of the Ag island films are obtained, and the resonance peak shifts toward longer wavelength with increasing Ag island size. The photoluminescence (PL) enhancement or quenching depends on the size of Ag islands, and PL enhancement by 1.6 times on the main PL band is obtained when the sputtering time is 10 min. Analyses show that the influence of surface plasmons on the PL of α-SiC:H is determined by the competition between the scattering and absorption of Ag islands, and PL enhancement is obtained when scattering is the main interaction between the Ag islands and incident light.     

新型交联壳聚糖树脂的制备及其对苯甲酸的吸附行为研究

以壳聚糖为原料,甲醛为预交联剂,环氧氯丙烷为交联剂,通过反相悬浮交联法制备出新型壳聚糖树脂,并用红外光谱和扫描电镜对其结构进行表征.测定了不同温度下新制备树脂自水中吸附苯甲酸的等温线,计算了吸附过程的热力学参数.并用Freundlich方程对实验数据进行拟合,发现该方程适用于所研究的吸附体系.体系的热力学与吸附机理密切相关,当苯甲酸浓度较低时,吸附为放热过程,体系熵减少,降温有利于吸附;当苯甲酸浓度较高时,吸附为吸热过程,体系熵增加,升温有利于吸附.     

混合制冷剂循环液化天然气流程(火用)分析

带丙烷预冷的混合制冷剂循环液化天然气流程具有高效及流程相对简单的优点.本文在对流程进行热力学分析的基础上,对流程进行(火用)分析.计算了流程中各设备的(火用)损失,计算结果表明,压缩机的(火用)损失约占整个流程(火用)损失的50%,换热器的(火用)损失约占总(火用)损失的26%.本文还分析了产生(火用)损失的原因,提出降低(火用)损失的措施.     

Design,Synthesis and Anticancer Activity Evaluation of Novel Quinazoline Derivatives as EFGR Inhibitors

Malignant tumor is one of the major diseases that seriously threaten human health today. Compared with traditional chemotherapy, targeted drug therapy has become a new idea of tumor therapy. And EGFR(epidermal growth factor receptor) is highly expressed in many human tumor cell lines, which is a biomarker of tumor proliferation. In this paper, small molecule tyrosine kinase inhibitors with quinazoline structure aiming at EGFR were studied. A series of novel quinazoline derivatives(4 a～4 l) have been designed and synthesized from 4-hydroxyquinazoline as the parent core. Structures of target compounds were characterized by ~1H NMR and ~(13)C NMR spectra. The in vitro anticancer activity of compounds 4 a～4 l was evaluated by MTT assay against Hela,MCF-7 and A549 tumor cell lines, and apoptosis-inducing capacity was investigated by Annexin-V/PI staining assay.The results showed that all compounds had good antitumor activity against the test tumor cell lines. Especially,compound 4 a exhibited the best anticancer activity(IC_(50) = 10.23 μM) against Hela cell lines, remarkable ability to induce apoptosis, and low toxicity, which identified 4 a as a promising anticancer drug aiming at EFGR.     

一种新颖的基于FTIR-CWT及ANN分类法的同科属中药材菟丝子与金灯藤的识别研究

采用水平衰减全反射傅里叶变换红外光谱法（HATR-FTIR）测定了同属种子植物中药材菟丝子及金灯藤的FTIR,运用基于连续小波多分辨率分析法对吸收较为相似的菟丝子及金灯藤的FTIR进行特征提取。选择第7、10、13分解层数的特征向量,进行人工神经网络（ANN）训练,再用训练出来的网络对不同产地的植物种子菟丝子和金灯藤所得FTIR小波提取的特征向量进行分类。通过对32个不同样本的验证,说明能够采用基于FTIR-连续小波特征提取及人工神经网络分类法对同科属中药材菟丝子与金灯藤进行识别。     

氮对金刚石缺陷发光的影响

利用低温显微荧光光谱研究了IIa型、Ib型、Ia型金刚石的缺陷发光性质. 研究发现, 随着氮含量增加, 间隙原子及空位逐渐被氮原子所束缚, 从而使得GR1中心、533.5 nm及580 nm中心等本征缺陷发光减弱, 而氮-空位复合缺陷(NV中心)及523.7 nm中心等氮相关缺陷发光增强. 高温退火后, 间隙原子与空位可以自由移动, IIa型金刚石中出现了NV⁰中心, Ib型金刚石中只剩下了NV中心, Ia型金刚石中氮原子之间发生团聚, 出现了H3中心及N3中心. 另外, 氮作为施主原子, 有利于负电荷缺陷的形成, 如3H 中心、NV^- 中心.     

Nonlinear consensus protocols for multi-agent systems based on centre manifold reduction

Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β--consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.     

NO自由基捕捉剂α,ω-双(咪唑啉硝酮氮氧)苯基聚醚的合成

ＮＯ是血管舒张代谢的产物．生物体内由ＮＯ自由基导致的不同生理作用之间存在复杂的平稳关系，近年来对ＮＯ的研究引起众多生物学家和化学家的极大兴趣［１］，特别关注于ＮＯ检测的研究．定量测定ＮＯ的方法已有多种［２，３］，但尚无直接从细胞或生物体系中检测ＮＯ的...