双奇核188Au的准粒子带结构研究

利用在束γ谱学实验技术, 通过¹⁷³Yb(¹⁹F,4nγ)反应 布居了¹⁸⁸Au的高自旋态, 并对其准粒子带结构进行了研究. 基于实验测量结果, 对原有的双奇核¹⁸⁸Au能级纲图做了较大的修改. 通过系统性比较, 对15⁺以上的能级结构进行了讨论.     

Lifetime measurement of the ((11/2)−) isomer in 125Cs

A new rotational band has been observed in ¹⁶⁷Lu by ¹⁵²Sm (¹⁹F,4n)reaction at the HI-13 tandem accelerator of CIAE in Beijing. The high spin transition energies of the new band are almost identical to the triaxial superdeformed bands recently discovered in ¹⁶³Lu and ¹⁶⁵Lu. This new band is predicted as a triaxial superdeformed band by total routhian surface calculations. Received: 6 October 1997     

Characteristic curved structure derived from collagen-containing tubular giant vesicles under static magnetic field

Collagen-containing tubular giant vesicles (Col–tGVs) under a high static magnetic field were found to constitute characteristic curved structures (e.g. circular, 8-figure, and hairpin-loop), which were sustained by polymerization of collagen units inside the tGV. We ascribed the formation of these structures to the elasticity of the tGV and to the competing diamagnetic anisotropies between collagen and the tGV. These curved structures can be well expressed by the equation of elastica.     

Electrochemical detection of lectin using a galactosamine labeled with daunomycin

To detect a lectin from soybean, an electrochemical procedure was developed by the use of a labeling of galactosamine. Because the lectin has binding sites to galactosamine, galactosamine labeled with daunomycin having electroactivity was prepared. When labeled galactosamine (LG) combines with lectin, the part of daunomycin is taken in the binding sites of the lectin and becomes electroinactive. Therefore, the concentration of the lectin can be estimated by measuring the peak current of the LG. On the other hand, a competitive reaction to the lectin of galactosamine and the LG makes a detection of galactosamine possible. This method has merit that does not require a separation procedure of the free LG from the bound one. An effect of length of spacer between daunomycin and galactosamine was also investigated. It was found that adsorption of reagent on the electrode increased due to introduction of the spacer. Furthermore, the electrode response of the LG was influenced by the type of the spacer.     

17O NMR chemical shifts versus structure relationships in oxiranes

Natural-abundance ¹⁷O NMR spectra have been measured for twenty one oxiranes. Their chemical shifts covering a 100 ppm range were interpreted in terms of the paramagnetic β- and diamagnetic γ-effects. In addition, through-space orbital interaction between the ethylenic π and the Walsh orbitals of the oxirane ring was suggested by a lowfield shift in norbornadiene $\text{exo}$-oxide.     

Determination of ofloxacin in human serum by high-performance liquid chromatography with column switching.

The chromatographic behaviour of ofloxacin on various sorbents, including ODS, C8, C1, nitril, phenyl and tert,-butyl, as stationary phases was investigated and a high-performance liquid chromatography (HPLC) assay was developed for the determination of ofloxacin in serum. The serum samples were directly introduced onto an HPLC column after filtering through a Morcut II membrane filter to remove proteins. The filtrate was concentrated on a pre-column using a phenyl stationary phase and was then introduced to an analytical column with an ODS stationary phase by column switching. Ofloxacin and enoxacin as an internal standard were detected by ultraviolet absorbance at 300 nm. Determination was possible for ofloxacin over the concentration range 50-2000 ng/ml; the limit of detection was 20 ng/ml. The recovery of ofloxacin added to serum was 88.8-101.7% with a coefficient of variation of less than 5.2%. This method is applicable to pharmacokinetic studies of patients after treatment with ofloxacin.     

Design and synthesis of highly sensitive and selective fluorescein-derived magnesium fluorescent probes and application to intracellular 3D Mg2+ imaging

The role of intracellular magnesium ions is of high interest in the fields of pharmacology and cellular biology. To accomplish the dynamic and three-dimensional imaging of intracellular Mg2+, there is a strong desire for the development of optimized Mg2+ fluorescent probes. In this paper we describe the design, synthesis, and cellular application of the three novel Mg2+ fluorescent probes KMG-101, -103, and -104. The compounds of this series feature a charged beta-diketone as a binding site specific for Mg2+ and a fluorescein residue as the fluorophore that can be excited with an Ar+ laser such as is widely used in confocal scanning microscopy. This molecular design leads to an intensive off-on-type fluorescent response toward Mg2+ ions. The two fluorescent probes KMG-103 and -104 showed suitable dissociation constants (Kd,Mg2+ = 2 mM) and nearly a 10-fold fluorescence enhancement over the intracellular magnesium ion concentration range (0.1-6 mM), allowing high-contrast, sensitive, and selective Mg2+ measurements. For intracellular applications, the membrane-permeable probe KMG-104AM was synthesized and successfully incorporated into PC12 cells. Upon application of the mitochondria uncoupler FCCP to the probe-incorporated cells, the resulting increase in the free magnesium ion concentration could be followed over time. By using a confocal microscope, the intracellular 3D magnesium ion concentration distributions were satisfactorily observed.     

Voltammetric investigation of avidin-biotin complex formation using an electroactive bisbiotinyl compound

Formation of avidin-biotin complex was investigated using bisbiotinyl thionine (BBT) by means of voltammetric techniques. Thionine is an electroactive compound and has two amino groups that are necessary for the reaction with a biotinylation reagent. The biotinylation of thionine produces a new reagent with two biotin moieties at each end of thionine. Three BBTs of different lengths of the spacer that connects the biotin moiety to the thionine moiety were prepared. The avidin-biotin binding assay was achieved by measuring the electrode response of the thionine moiety in BBT. The binding affinity and the conformation of complex, which depended on the length of spacer, are discussed. BBT in which the spacer is shortest (BBT-S, distance between carbonyl group of the two biotin moieties: 11 Å) binds with only one avidin molecule. BBT with medium length of spacer (BBT-M, 28.8 Å) forms the complex with two avidin molecules. BBT with the longest spacer (BBT-L, 46.6 Å) allows binding with two avidin molecules as well as intramolecular binding within one avidin molecule. The affinity constants of BBT-S, BBT-M and BBT-L for avidin were estimated to be 7.0 × 10¹² M⁻¹, 3.2 × 10¹² M⁻¹ and 4.0 × 10¹² M⁻¹, respectively.     

Quantum dynamics driven by continuous laser fields under measurements: towards measurement-assisted quantum dynamics control

We study quantum system dynamics driven by continuous laser fields under the measurement process. In order to take into account the system transition due to the measurement, we define the superoperator which eliminates the coherence relevant to the measured quantum states. We clarify that the dynamics of the measured states is frozen in the frequent measurement limit, while the space spanned by unmeasured states is isolated from the original system. We also derive the effective Liouvillian which governs incoherent population dynamics under the condition, in which measurements are frequently applied. We apply the formulation to two-level and Lambda-type three-level systems and clarify how the quantum measurements hinder the coherent population dynamics driven by the continuous laser fields in practical examples. Analysis on the laser field amplitude dependency of the final distribution in the t-->infinity limit suggests the possibility of the measurement-assisted quantum control.