[en] Some technological operational states are monitored through the analysis of trace uranium in nuclear fuel reprocessing pilot plant, so the analysis of trace uranium plays important role in the pilot plant. Time-resolved fluorescent (TRF) method is used to analyze trace uranium in the analytical laboratory of pilot plant, but the accuracy of measuring results is not very good because of the existence of some interfering ions. For accurate determination of UO₂²⁺, a rapid and simple sample pretreatment method that can eliminate the influences is established, which can meet the demand of the trace uranium analysis in nuclear fuel reprocessing pilot plant. In this method, a new type of ion exchange materials-ion exchange fiber (IEF) has been used to remove the interfering ions. The s_r is 5% (n = 6) in this work. The determination results are accurate and reliable by t test (α = 0.02). (authors)

[en] Interfering ions are the main influencing factors to time resolved fluorescence (TRF) analyses of trace uranium. The influence of H⁺ , Fe³⁺ and NO₃^- are studied in this paper. The fluorescence intensity of uranyl fluorescent complex is greatly affected by nitric acid. The fluorescence are completely quenched when the concentration of nitric acid is 0.075 mol/L. The concentration and lifetime of fluorescent complex are reduced by the addition of H⁺. The fluorescence intensity is also affected by Fe³⁺ and NO₃^- because of the absorption of exciting light. (authors)

[en] An exactly analytical method is needed to detect the thorium in nuclear products. The nuclear sample is complexity, strong radioactivity, and toxicity. It should be separated before be measured. The separate conditions of Th (IV) with coexisting ions such as UO₂²⁺, Fe³⁺, Zr⁴⁺ etc. by CL-TBP resin were studied. A new fluorescence analysis method for the determination of thorium was developed. The linear ranger is 0-500 μg/L and the detection limit is 0.1 μg/L. For samples as 1 μg/L and 50 μg/L, precision are 2.5% and 0.6%. For simulate sample, the relative standard deviation is 3% and the recovery is between in 92%-100%. (authors)

[en] Based on the chromogenic reaction of Ag with p-dimethylamino benzyl rhodanine, a new spectrophotometric method for determination of Ag in the presence of PVA-124 and Triton X-100 as surfactant is established. The factors such as acidity, reaction time and the concentration of surfactant were studied. The results show that the appropriate conditions are as the following. The concentrations of p-dimethylamino benzyl rhodanine, PVA and Triton X-100 are 0.1 g·L"-"1, 10 g·L"-"1 and 0.16% respectively. Acidity is 1.0 mol·L"-"1. Reaction time is 20 minutes. Absorption wavelength is 470 nm. The influence of several coexisting ions, especially Pu (Ⅳ) on analyzing Ag is also studied. The results indicate that when the concentration of Ag is less than five times of the concentration of Pu. PMBP is used to extract Pu (Ⅳ). The optimum extraction conditions are as follows. The concentration of PMBP is 0.1 mol·L-1. Acidity is 2.0 mol·L-1. The ratio of organic and water phase is 1:1. Extraction time is 3 minutes. Conformity to Berr's law was obtained with the scope of 0.1-1.0 μg·mL"-"1. The determination limit of Ag is 0.1 μg·mL"-"1. The relative standard deviation for this method is 2.6% (n=3). The recovery is 104-114%. (authors)

[en] The determination of free-acid plays an important role in spent fuel reprocessing analysis. Its work accounts for about 30% of all analytical work in reprocessing. It is necessary to study and develop a special fast analytical system for determination of free acid. The special analytical system is particularly applicable to determination of free acid in high-level radioactive environment, which is composed of an optical fiber spectrophotometer and an automatic sample-in device. Small sample-in volume needed, fast procedure, easy operation and physical protection are its advantages. All kinds of performance and parameters satisfy the requirements of spent fuel reprocessing control analysis. For long-distance determination, the optical fiber spectrophotometer is connected with an 4.5 meters long optical fiber. To resolve the change of 0.1 mol/L acidity, the measuring optical path is 2 cm. Mass of 10-20 μm in diameter optical fibers are assembled. The optical fiber probe is composed of a reflecting mirror and a concave mirror on the top of optical fibers. To eliminate the interference of external light, a stainless steel measuring chamber is used. The automatic sample-in device is composed of state valve, quantifying pump and pipe. The sample-in precision of 15 μl and 35 μl quantifying loops is better than 0.5%. The special analytical system takes less than 7 minutes to complete one measurement. The linear range is 0.5 mol/L-3.5 mol/L. The relative standard deviation is better than 2.0% when the concentration of the free acid is about 2.0 mol/L. For samples in different medium, the results are comparable with the method of pH titration of determining the free acid in reprocessing. (authors)

[en] Objective: To establish a radioimmunoassay method (RIA) for the measurement of human serum apo-H. Methods: Apolipoprotein H (apo-H) was isolated and purified from human plasma. The antisera against apo-H was obtained by immunizing rabbits, then, Apo-H was labelled with ¹²⁵I by iodogen method. Results: The sensitivity was 2.33 mg/L, and the assay range covered 5-320 mg/L for apo-H. The intra-assay and inter-assay CV were 4. 93% and 4.01% respectively, with a recovery rate of 95.7%. There was no cross reaction with apo-AI and apo-B. Normal mean value of serum apo-H was 230.17 +- 5.64 mg/L in males (n = 41) and 200.27 +- 4.25 mg/L in females (n = 50) without significant sex difference

[en] To study the offectineness of labelled chlorpro mazine for the determination of dopa- mine 2(D₂) receptor in rat striatum, the chlorpromazine-tyramine, which was synthesized by coupling chlorpromazine to tyramine, was ¹²⁵I_labelled by Iodogen method and used as radioactive ligands. Non-labelled ligands were set to compete with ¹²⁵I-labelled competitors of different concentrations. The ¹²⁵I-labelled chlorpromazine-tyramine could be bound to D₂ receptor in rat striatum. The binding affinity was strong and the rolated data were stable, suggesting that ¹²⁵I- labelled chlorpromazine -tyramine is useful for determining 2(D₂) receptor. (authors)

[en] Highlights: • Hemodialysis is widely used to evaluate patients suffering from renal insufficiency. • The normal membrane can activate platelets, followed by thrombosis and inflammation. • Antiplatelet is crucial for improving the hemocompatibility of dialysis membrane. • Protease activated receptor is a platelet receptor that raises platelet activation. • Inhibition protease activated receptor can improve the hemocompatibility of membrane. Hemodialysis therapy is intended for patients suffering from renal insufficiency, pancreatitis, and other serious diseases. Platelets are an important active ingredient in the thrombosis induced by hemodialysis membranes. So far, there are few studies of hemodialysis membranes focusing on the effects of protease-activated receptor 1 (PAR1) activation on the platelet membrane. Among various antithrombotic agents, vorapaxar is a novel PAR1 inhibitor with high efficacy. In this study, we constructed a vorapaxar-modified polysulfone (VMPSf) membrane using immersion-precipitation phase transformation methods and characterized the microstructure in terms of hydrophilicity and mechanical properties. The water contact angle of the VMPSf membrane was 22.45% lower than that of the PSf membrane. A focused determination of platelet morphology was obtained using scanning electron microscopy. Meanwhile, we evaluated the effects of a VMPSf membrane on platelet adhesion. We observed that the VMPSf membrane could reduce the number of adhered platelets without altering their spherical or elliptical shape. The PAR1 levels in VMPSf membranes were 7.4 MFI lower than those in PSf membranes, suggesting that this modified membrane can effectively inhibit platelet activation. Activated partial thromboplastin time (APTT, 5.3 s extension) and thrombin time (TT, 2.1 s extension) reflect good anticoagulant properties. Recalcification time (80.6 s extension) and fibrinogen adsorption (9.9 μg/cm² reduction) were related to antithrombotic properties. To determine the biosafety of VMPSf membranes, we investigated antianaphylactic and anti-inflammatory properties in vitro and acute toxicity in vivo, it was obvious that C3a and C5a had decreased to 9.6 and 0.8 ng/mL, respectively. The results indicated that the VMPSf membrane has potential for clinical application.

[en] We investigate the granular flow states in a channel with bottleneck by molecular dynamics simulations. Our study is restricted only on a selected key area rather than on the whole system to focus on the flow properties of a single granular state. A random force field is introduced to control the granular temperature. It is also pointed out that the flow rate in the granular flow can be correlated with the pressure, which leads us to carry out a comprehensive study similar to the classical study for general liquid-gas phase transition. Our results show that the dilute flow state and the dense flow state of the granules are similar to the gas state and the liquid state of general substances, respectively, and the properties of phase transition and critical phenomenon are also similar to those occurring in general substances. (paper)

[en] Abstract Background: Molten fluoride salts which have good heat transfer and neutron characteristic, were used as the primary and secondary coolants in the loops of thorium molten salt reactor (TMSR) that is a candidate of the generation IV reactor. Structure of molten salt plays an important role in the design, construction and safe operation of molten salt reactor. Infrared absorption spectroscopy (IR)is one of the powerful tools to study the structure of molten salt. However, the commercial standard instrument cannot realize high temperature measurement. Purpose:This study aims to obtain the infrared absorption spectra of molten fluoride salt at the temperature up to 600 ℃ by developing an instrument constructed from commercially available components. Methods: The main component of instrument is a Fourier transformation infrared (FTIR) spectrometer with wavenumber range of 14700-400 cm^-1. Adetachable bottom board in sample compartment was built to allow a furnace to be put in it. The furnace was designed to be two-half pattern for the cuvette to be placed into and out of freely. It can be operated from room temperature to about 600 ℃. The cuvette, the most important component in the instrument, is made by Hastelloy C/N as the main body with a reverse 'T' contour and diamond or crystalline SiC as the window plates. An optical translation stage was installed under the furnace to connect the furnace with the bottom board, which can make sure that the focus of light beam is overlapped with the center of cuvette. Results: Performances of the instrument are demonstrated and verified with spectral studies of water at room temperature and molten salt nitrite at high temperature. Conclusion: Using this instrument, the spectra of the molten fluoride salt (FLiBe)have been obtained. (authors)