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- Author or Editor: Ye Li x
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Abstract
The phenomenon of all-elements-sleeping-beauties in science is revealed by four special cases. The ‘sleeping beauties’ prick their fingers on the ‘spindles’ so that they fall into sleep then are awakened by their ‘princes’. The authors speculate that the phenomenon could happen in scientific literatures with high quality.
Abstract
The relative errors (e%) in the determination of the activation energy from the slope of the Kissinger straight line ln(β/βT p 2) vs. 1/T p (β is the heating rate) are in-depth discussion. Our work shows that the relative errors is a function containing the factors of x p and Δx p, not only x p (x p = E/RT p, E is the activation energy, T p is the temperature corresponding to maximum process rate, R is the gas constant). The relative error between E k and E p will be smaller with the increase of the value of x and/or with the decrease of the value of Δx. For a set of different heating rates in thermal analysis experiments, the low and close heating rates are proposed from the kinetic theory.
Abstract
This study is aimed at observing the apoptosis and Bcl-2/Bax gene expression of mammalian cells following heavy-ion and X-ray irradiations. Exponentially growing human hepatoma SMMC-7721 cells cultured in vitro were irradiated with a 12C ion beam of 50 MeV/u (corresponding to a LET value of 44.56 keV/μm) from Heavy Ion Research Facility in Lanzhou (HIRFL) at doses varying from 0 to 3 Gy. The X-ray irradiation (8 MV) was performed in the therapy unit of the General Hospital of the Lanzhou Military Area. Survival fractions of irradiated cells at various doses were measured by means of MTT assay. Apoptotic cells after irradiation were analyzed with fluorescence microscope and flow cytometer (FCM). Immuno-histological assay were applied to detect the expression of Bcl-2/Bax genes in the irradiated cells. The survival fraction of SMMC-7721 cells decreased gradually (vs. control p<0.05) with increasing the dose of the carbon ion beam more obviously than X-ray irradiation, and the carbon ion irradiation efficiently induced cell apoptosis and significantly promoted the expression of Bax gene while Bcl-2 gene expression was restrained. High-LET heavy ion beam would induce cell apoptosis effectively than low-LET X-ray, and the apoptosis rate is correlated with the transcription of Bcl-2/Bax and the ratio of Bcl-2/Bax in human hepatoma SMMC-7721 cells after irradiation to heavy ion beam.
Abstract
The complex of [Nd(BA)3bipy]2 (BA = benzoic acid; bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR spectra, single crystal X-ray diffraction, and TG/DTG techniques. The crystal is monoclinic with space group P2(1)/n. The two–eight coordinated Nd3+ ions are linked together by four bridged BA ligands and each Nd3+ ion is further bonded to one chelated bidentate BA ligand and one 2,2′-bipyridine molecule. The thermal decomposition process of the title complex was discussed by TG/DTG and IR techniques. The non-isothermal kinetics was investigated by using double equal-double step method. The kinetic equation for the first stage can be expressed as dα/dt = A exp(−E/RT)(1 − α). The thermodynamic parameters (ΔH ≠, ΔG ≠, and ΔS ≠) and kinetic parameters (activation energy E and pre-exponential factor A) were also calculated.
Abstract
Abstract
A rapid separation system based on SISAK technique was established to isolate 142La successfully from fission products. SISAK technique is often applied in the separation of nuclides with the half-life of seconds or minutes. Here it was used to separate the parent nuclide of 142La, which the half-life is in the magnitude of several seconds. According to the separation procedure designed in the paper, the activity of 142La acquired is more than 104 Bq and the decontamination factors for most γ-emitters are higher than 103.
Abstract
Bombs concealed in luggage have threatened human life and property throughout the world's traffic. The plastic explosives could not be checked by the X-ray detecting device. A method has been tested in the present work for non-destructive detection of explosives. A neutron generator and relevant apparatus have been used as a tool to find explosives, regardless of the bomb's shape and the packing materials. It seems that this method is a promising one because of the strong transmission ability of both the incident and output specific radiations and low background.
Abstract
This paper reports the study of hydrogen and carbon monoxide produced by radiation degradation of N, N-dimethylhydroxylamine (DMHA). The results show that when the concentration of DMHA is between 0.1M–0.5M and the dose is between 10–1000 kGy, the volume fraction of hydrogen is very high and increases with the dose. The volume fraction of hydrogen is little dependent on the concentration of DMHA at lower dose but increases with increasing concentration of DMHA at higher dose. The volume fraction of carbon monoxide is very low.
Abstract
Acute respiratory distress syndrome (ARDS) refers to the injury of alveolar epithelial cells and capillary endothelial cells due to various injury factors. Research on the pathogenesis of ARDS has made great progress, but the exact pathogenesis of ARDS has not been fully elucidated. Up to now, the prevention and treatment of ARDS is still an important scientific problem that needs to be solved urgently. In this work, we analyzed the effect of uridine on ARDS. An ARDS model was successfully constructed by lipopolysaccharide (LPS) stimulation. Western-blotting, IFA, ELISA, RT-PCT and CLSM were conducted to investigate the effect of uridine on ARDS and insulin resistance, and the results showed that lung histopathological alterations were significantly attenuated by uridine treatment. Further work showed that the levels of proinflammatory cytokines were significantly down-regulated in the lung tissue after treatment with uridine. Additionally, the numbers of total cells and neutrophils in the bronchoalveolar lavage fluid (BALF) were also decreased in the uridine-treated ARDS mice. We further explored the potential mechanism by which uridine could treat ARDS, and the results indicated that NF-κB signaling was down-regulated by uridine treatment. Next, we studied insulin sensitivity in the ARDS mice, and found that insulin signaling was significantly down-regulated, and uridine could enhance insulin sensitivity in the ARDS mice model. Furthermore, we found that the levels of inflammation and oxidative stress were decreased by uridine treatment, which may be the potential mechanism by which uridine could improve insulin sensitivity. Taken together, the current work provides evidence that uridine can serve as a potential drug to treat ARDS and insulin resistance.
Abstract
Oxidation of Pu(III) in 1 bp solution to Pu(IV) was studied using the salt-free oxidant N2O4. It was proved that the reductants N,N-dimethylhydroxylamine (DMHAN) and monomethyl-hydrazine (MMH) present in 1 bp solution of CIAE-APOR process can be oxidized and removed from the solutions also by N2O4 before the oxidation of Pu(III). The effects of the acidity, the temperature and the amount of N2O4 added on the oxidation of DMHAN and MMH were studied.
