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51.
With the development of metal-based drugs, Ru(II) compounds present potential applications of PDT (photodynamic therapy) and anticancer reagents. We herein synthesized two naphthyl-appended ruthenium complexes by the combination of the ligand with naphthyl and bipyridyl. The DNA affinities, photocleavage abilities, and photocytotoxicity were studied by various spectral methods, viscosity measurement, theoretical computation method, gel electrophoresis, and MTT method. Two complexes exhibited strong interaction with calf thymus DNA by intercalation. Production of singlet oxygen (1O2) led to obvious DNA photocleavage activities of two complexes under 365 nm light. Furthermore, two complexes displayed obvious photocytotoxicity and low dark cytotoxicity towards Hela, A549, and A375 cells. 相似文献
52.
As multilayer networks are widely applied in modern society, numerous studies have shown the impact of a multilayer network structure and the network nature on the proportion of cooperators in the network. In this paper, we use Barabási–Albert scale-free networks (BA) and Watts and Strogatz networks (WS) to build a multilayer network structure, and we propose a new strategy-updating rule called “cooperation-defection dominance”, which can be likened to dominant and recessive traits in biogenetics. With the newly constructed multilayer network structure and the strategy-updating rules, based on the simulation results, we find that in the BA-BA network, the cooperation dominance strategy can make the networks with different rs show a cooperative trend, while the defection dominance strategy only has an obvious effect on the network cooperation with a larger r. When the BA network is connected to the WS network, we find that the effect of strategy on the proportion of cooperators in the network decreases, and the main influencing factor is the structure of the network. In the three-layer network, the cooperation dominance strategy has a greater impact on the BA network, and the proportion of the cooperators is enhanced more than under the natural evolution strategy, but the promotion effect is still smaller than that of the two-layer BA network because of the WS network. Under the defection dominance strategy, the WS layer appears different from the first two strategies, and we conclude through simulation that when the payoff parameter is at the middle level, its cooperator proportion will be suppressed, and we deduce that the proportion of cooperators and defectors, as well as the payoff, play an important role. 相似文献
53.
Although most list-ranking frameworks are based on multilayer perceptrons (MLP), they still face limitations within the method itself in the field of recommender systems in two respects: (1) MLP suffer from overfitting when dealing with sparse vectors. At the same time, the model itself tends to learn in-depth features of user–item interaction behavior but ignores some low-rank and shallow information present in the matrix. (2) Existing ranking methods cannot effectively deal with the problem of ranking between items with the same rating value and the problem of inconsistent independence in reality. We propose a list ranking framework based on linear and non-linear fusion for recommendation from implicit feedback, named RBLF. First, the model uses dense vectors to represent users and items through one-hot encoding and embedding. Second, to jointly learn shallow and deep user–item interaction, we use the interaction grabbing layer to capture the user–item interaction behavior through dense vectors of users and items. Finally, RBLF uses the Bayesian collaborative ranking to better fit the characteristics of implicit feedback. Eventually, the experiments show that the performance of RBLF obtains a significant improvement. 相似文献
54.
采用二苯碳酰二肼为络合剂,正戊醇为萃取剂,乙醇为助溶剂,建立了微珠析相微萃取-石墨炉原子吸收法测定地质样品中痕量Cr的分析方法。实验详细探讨了微珠析相微萃取的析相条件、石墨炉原子吸收工作参数及共存离子的干扰,优化了体系萃取条件。实验结果表明:微珠析相微萃取既起到了分离富集的作用,在石墨炉升温程序中又起到了基体改进剂的作用;当萃取剂用量为0.2~1.5 mL时,使之与水完全互溶所需助溶剂体积约为水相体积的0.2~0.5倍;方法线性范围为0~10 μg·L-1,检出限为0.057 μg·L-1,相对标准偏差(RSD)为3.3%(c= 2.5 μg·L-1,n=11);当萃取剂用量为1.5 mL、水相体积15 mL时,与直接溶液进样相比其灵敏度可提高10倍。所建立的方法用于地质标准参考物质AGV-2和G-2中Cr的测定,测定值与参考值具有较好的一致性。 相似文献
55.
建立了气相色谱-质谱联用(GC-MS)测定环己烷中乙二醇二乙醚、邻甲基苯甲酸甲酯、五甲基二乙烯三胺、邻苯二甲酸二甲酯含量的方法.环己烷直接进样,通过毛细管柱DB-5,30m×0.25mm×0.5μm分离,由电子轰击源(EI)选择离子监测(SIM)模式下进行检测.结果表明,杂质的校准曲线相关系数均在0.9974-0.9996,相对标准偏差为4.6%-8.9%,回收率为93.3%-105.0%. 相似文献
56.
将可电化学再生的电致化学发光试剂-三联吡啶钌固定于电极表面制备得到可再生的电致化学发光(ECL)传感器.综述了近年来使用离子交换聚合物膜固定三联吡啶钌ECL传感器的研究进展,简要介绍了不同离子交换聚合物的固定方法及其相关的应用情况.同时展望了该领域未来的发展方向和前景. 相似文献
57.
饲料中添加30%鱼粉为对照组饲料和6组试验饲料(分别替代对照组中16.67%、33.33%和50.00%的鱼粉,同一鱼粉替代水平的2组分别添加晶体蛋氨酸和羟基蛋氨酸钙,使其蛋氨酸含量与对照组一致)喂养罗氏沼虾(初始体重为(0.29±0.04) g )10周,研究不同鱼粉替代水平下,分别添加晶体蛋氨酸和羟基蛋氨酸钙对罗氏沼虾幼虾生长性能和血清生化指标的影响.结果表明:复合蛋白源替代对照组16.67%鱼粉并补充羟基蛋氨酸钙组的增重率、特定生长率、蛋白质效率和饲料系数同对照组无显著差异(P>0.05);同一鱼粉替代水平下,羟基蛋氨酸钙组的增重率、特定生长率和蛋白质效率均显著高于晶体蛋氨酸组(P<0.05).血清生化组成的分析结果表明:血清总蛋白含量各处理组之间差异显著(P<0.05),对照组血清谷草转氨酶和谷丙转氨酶活力显著低于其他各组(P<0.05),其中同一替代水平下,饲料中添加羟基蛋氨酸钙组谷草转氨酶和谷丙转氨酶活力低于添加晶体蛋氨酸组.由此可见,与晶体蛋氨酸相比,羟基蛋氨酸钙能更有效提高罗氏沼虾生长性能和饲料利用效率. 相似文献
58.
研究发现,颗粒物质层被匀速推移挤压过程中,所需推移力先以线性规律增加,在某一确定点后,则会以指数规律增加.而颗粒物质是由众多离散颗粒组成的软凝聚态物质,其宏观上反映的是离散颗粒的个体性质和凝聚态物质的集体效应.颗粒与颗粒之间以及颗粒与边界之间的细观尺度接触力链的构成以及演变规律将会直接影响各种宏观受力情况,其摩擦力与挤压力便是力链的主要构成形式.围绕着定量描述细观力链特征,从而揭示力的变化规律这一目标,采用计算机模拟的方法,依照球形颗粒Hertz法向接触理论和Mindlin-Deresiewicz切向接触理论,对重力作用下不同数目的三维等径球体颗粒层的推移情况进行了离散元仿真模拟,量化分析了推移力变化规律、各摩擦力变化规律以及力链分布规律,发现摩擦力与挤压力在颗粒堆积的不同阶段对力链的构成起到了不同的主次作用,使得力链发生强弱演变,从而发现了推移颗粒物质层时推移力的变化规律及原因.这些结果有利于从力链角度揭示颗粒内部和颗粒与各边界之间的受力情况. 相似文献
59.
A micro-Gal absolute gravimeter based on high-precision and high-stability heterodyne interferometer is presented. The distance measuring technology of the gravimeter is studied in detail. The experimental results of distance measuring for a free-falling motion show that the high-precision heterodyne interferometer described in this paper can meet the demand of a micro-Gal absolute gravimeter with relative uncertainty of 6.4 × 10-9. Moreover, the heterodyne interferometer is more stable than the Mach-Zehnder interferometer (MZI) which is widely used in present absolute gravimeters. 相似文献
60.
Oscillation of coercivity between positive and negative in MnxGe1-x:H ferromagnetic semiconductor films 下载免费PDF全文
Amorphous MnxGe1-x :H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron cosputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x :H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6 :H film, the inverted Hall loop is also observed at 30 K, which is consistent with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics. 相似文献