Precise Quantification of Molybdate In Vitro by the FRET-Based Nanosensor ‘MolyProbe’

Molybdenum (Mo) is an essential trace element in all kingdoms of life. Mo is bioavailable as the oxyanion molybdate and gains biological activity in eukaryotes when bound to molybdopterin, forming the molybdenum cofactor. The imbalance of molybdate homeostasis results in growth deficiencies or toxic symptoms within plants, fungi and animals. Recently, fluorescence resonance energy transfer (FRET) methods have emerged, monitoring cellular and subcellular molybdate distribution dynamics using a genetically encoded molybdate-specific FRET nanosensor, named MolyProbe. Here, we show that the MolyProbe system is a fast and reliable in vitro assay for quantitative molybdate determination. We added a Strep-TagII affinity tag to the MolyProbe protein for quick and easy purification. This MolyProbe is highly stable, resistant to freezing and can be stored for several weeks at 4 °C. Furthermore, the molybdate sensitivity of the assay peaked at low nM levels. Additionally, The MolyProbe was applied in vitro for quantitative molybdate determination in cell extracts of the plant Arabidopsis thaliana, the fungus Neurospora crassa and the yeast Saccharomyces cerevisiae. Our results show the functionality of the Arabidopsis thaliana molybdate transporter MOT1.1 and indicate that FRET-based molybdate detection is an excellent tool for measuring bioavailable Mo.     

Tropaeolin OO as a Chemical Sensor for a Trace Amount of Pd(II) Ions Determination

The selective determination of metals in waste solutions is a very important aspect of the industry and environmental protection. Knowledge of the contents and composition of the waste can contribute to design an efficient process separation and recovery of valuable metals. The problematic issue is primarily the correct determination of metals with similar properties such as palladium and platinum. Thus this paper focuses on the development of a selective method that enables Pd(II) determination in the presence of Pt(IV) ions using the azo-dye tropaeolin OO (TR). For this purpose, the process of the metalorganic complex formation and Pd(II) ions determination were studied by using UV–Vis spectrophotometry under different conditions: solvents (water and B-R buffer), pH (2.09–6.09), temperature (20–60 °C), anions and cations concentrations. The formed metalorganic complex between Pd and tropaeolin OO allows for distinguishing Pd(II) ions from both platinum complexes, i.e. Pt(II), Pt(IV). Moreover, the proposed method can be applied to solutions containing both chloride and chlorate ions. The obtained characteristic spectrum with two maxima allows the determination of palladium even in the presence of other cations (Na, K, Mg, Zn, Co, Ni, Al) and changed concentrations of Pt(IV) ions. Furthermore, the developed spectrophotometric method for the Pd(II) ions determination using tropaeolin OO is characterized by high selectivity towards palladium ions.     

Joint Detection of Community and Structural Hole Spanner of Networks in Hyperbolic Space

Community detection and structural hole spanner (the node bridging different communities) identification, revealing the mesoscopic and microscopic structural properties of complex networks, have drawn much attention in recent years. As the determinant of mesoscopic structure, communities and structural hole spanners discover the clustering and hierarchy of networks, which has a key impact on transmission phenomena such as epidemic transmission, information diffusion, etc. However, most existing studies address the two tasks independently, which ignores the structural correlation between mesoscale and microscale and suffers from high computational costs. In this article, we propose an algorithm for simultaneously detecting communities and structural hole spanners via hyperbolic embedding (SDHE). Specifically, we first embed networks into a hyperbolic plane, in which, the angular distribution of the nodes reveals community structures of the embedded network. Then, we analyze the critical gap to detect communities and the angular region where structural hole spanners may exist. Finally, we identify structural hole spanners via two-step connectivity. Experimental results on synthetic networks and real networks demonstrate the effectiveness of our proposed algorithm compared with several state-of-the-art methods.     

Luminescent Properties of Zeolite Modified by Eu(III) and Tb(III) Complexes

The luminescence of the sorbates of the Eu(III) and Tb(III) complexes on the CaA-type zeolite with derivatives of aliphatic and aromatic carbonic acids has been studied. It is shown that the luminescent materials obtained can be used as light regulators and transformers which absorb energy in the UV spectral region and transform it into visible radiation.     

（Ti,Al）N薄膜光学性能的研究

研究了（Ｔｉ，Ａｌ）薄膜的光学特性，对其反射和透射光谱作了仔细分析。运用Ｈａｄｌｅｙ方程，算出一定成分（Ｔｉ，Ａｌ）Ｎ膜的折射率ｎ，消光系数ｋ随波长的变化关系。又根据透射曲线，计算出了（Ｔｉ，Ａｌ）Ｎ膜的光隙能。     

Selective hydroaminomethylation of olefins using simple and efficient Rh–phosphinite complex catalyst

Hydroaminomethylation of various olefins with primary and secondary amines was carried out using a simple and efficient rhodium–phosphinite complex catalyst. The influence of various reaction parameters including the effects of temperature, pressure, catalyst loading, time and solvents has been investigated. The present protocol is general with wider substrate applicability for the synthesis of an important class of aliphatic amines and arylethylamines. High activity and selectivity for amines was achieved with a very good substrate/catalyst molar ratio (turnover number 2500) under mild reaction conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

Unique ion beam scattering technique on depth profile determination

Abstract

By combination of energy and time of flight detection in ERDA or NRA measurement, the particles' masses can be determined, additionally to the depth information. This leads to unique depth profile determination even for complex targets. Combination with th concept of Jacobi transformations results in extremely fast measurements. In this paper, a way is shown how this concept can be realized even for accelerators ofenergies as low as about 1 MeV.     

一个吡啶二甲酸镉配位聚合物的合成、晶体结构及荧光性质

通过水热方法,采用H3CAM(H3CAM=4-hydroxy-pyridine-2,6-dicarboxylic acid)与Cd(NO3)2.4H2O反应,合成了1个镉配位聚合物[Cd4(HCAM)4(H2O)8]n(1),并对其结构和荧光性质进行了研究。结构分析结果表明该配合物属于单斜晶系,C2/c空间群。四个HCAM2-配体桥联4个镉离子形成了1个四核镉单元。这些孤立的单元通过氢键作用形成了1个三维配位框架。研究表明,该配合物在室温下能发出兰色荧光。     

Binuclear ruthenium(II) pyridazine complex catalyzed transfer hydrogenation of ketones

A convenient and general method of synthesis of binuclear ruthenium(II) pyridazine complex was reported. The synthesized complex was characterized by analytical and spectral methods. The structure of the complex was confirmed by X-ray diffraction technique and was found to be an efficient catalyst for the transfer hydrogenation of ketones with excellent conversions in the presence of isopropanol/KOH at 82 °C. The effect of solvents, bases, and different catalyst/substrate ratio for the reaction was also investigated.