[Preliminary study of atomic emission spectrometry of Ti (H) plasma produced by vacuum arc ion source].

In order to study the discharge process of vacuum arc ion source, make a detail description of the discharge plasma, and lay the foundation for further research on ion source, atomic emission spectrometry was used to diagnose the parameters of plasma produced by vaccum arc ion source. In the present paper, two kinds of analysis method for the emission spectra data collected by a spectrometer were developed. Those were based in the stark broadening of spectral lines and Saba-Boltzmann equation. Using those two methods, the electron temperature, electron number density and the ion temperature of the plasma can be determined. The emission spectroscopy data used in this paper was collected from the plasma produced by a vacuum are ion source whose cathode was made by Ti material (which adsorbed hydrogen during storage procedure). Both of the two methods were used to diagnose the plasma parameters and judge the thermal motion state of the plasma. Otherwise, the validity of the diagnostic results by the two methods were analyzed and compared. In addition, the affection from laboratory background radiation during the spectral acquisition process was discussed.

[Two-temperature diagnostic studies by emission spectra for nonequilibrium Ti-H plasma].

Using the T-H solid solution made by titanium absorbed hydrogen as the cathode, the Ti-H plasma produced by the pulsed vacuum are ion source was nonequilibrium: it contained both the component of titanium and hydrogen; there existed gradient in the radiaL, the horizontal and the time. As a result, it could not be described by a single temperature. The present paper assumed that the subsystem consisting of electrons and the subsystem consisting of other heavy particles reached equilibrium respectively, meaning that the Ti-H plasma was described by the two temperatures as electron temperature and heavy ion temperature, it was non-equilibrium two-temperature plasma Using Culdberg-Waage dissociation equation to describe the molecular dissociation process in the system, using Saha ionization equation to describe the atomic ionization process, combining plasma's charge quasi-neutral condition and introducing atomic emission spectroscopy as a plasma diagnostic method which would not interfere the plasma at the same time; the temperature and the particle number density of the Ti-H plasma were diagnosed. Using MATLAB as a tool, both the titanium atoms and monovalent titanium ions' ionization were considered, and the calculated results showed that with the electtron density determined by the Stark broadening of spectral lines in advance, except the heavy particle temperature and the hydrogen number density, the Ti-H plasma's parameters could be diagnosed fairly accurately; the accuracy of the electron density values had a great effect on the calculation results; if the heavy particle temperature could be determined in advance, the temperature and the particle number density of the Ti-H plasma could be accurately analyzed quantitatively.

[The effect of smoking and smoking cessation on the phosphorylation of IKK-ß in type 2 diabetic rats].

OBJECTIVE: To investigate the effect of smoking and smoking cessation on the phosphorylation of IKK-ß in type 2 diabetic rats. METHODS: Forty-two six-week-old Wistar rats were randomly divided into 4 groups: normal control (NC, n = 7), diabetes control (DC, n = 7), diabetes with smoking (DS, n = 14) and diabetes with smoking cessation (SC, n = 14). Rats in DS and SC groups were further assigned randomly into 8w and 12w subgroups. DS group was given passive smoking twice a day for 8 or 12 weeks, while SC group ceased passive smoking for 4 weeks after 8 or 12 weeks of smoking. Western blot method was used to detect the level of IKK-ß phosphorylation in skeletal muscle. RESULTS: Compared with the NC group, the phosphorylation of IKK-ß protein in DC group was increased (0.16 ± 0.05 vs 0.30 ± 0.08, P < 0.01). There was an increasing trend with the phosphorylation level of IKK-ß in the DS (8w) subgroup, but there was no statistical difference between the DC group and SC (8w) subgroup (0.40 ± 0.09 vs 0.30 ± 0.08, 0.36 ± 0.10, P > 0.05). The phosphorylation level of IKK-ß in DS (12w) group increased obviously, being significantly higher than that in the DC group and SC (12w) subgroup (0.74 ± 0.11 vs 0.30 ± 0.08, 0.35 ± 0.07, P < 0.01). CONCLUSION: With the prolongation of smoking duration, the phosphorylation of IKK-ß in type 2 diabetic rats increased. After smoking cessation, the phosphorylation of IKK-ß decreased. The phosphorylation of IKK-ß may be involved in the mechanism by which smoking causes type 2 diabetes.

[Recombinant human pigment epithelium-derived factor inhibits the proliferation of the endothelial cells from blood vessels].

OBJECTIVE: To express and purify the recombinant human pigment epithelium-derived factor (PEDF) which inhibits the proliferation of the endothelium cells from blood vessel in E.coli. METHODS: PEDF gene was inserted into the prokaryotic expression vector pGEX-4T-2. The recombinant protein PEDF was expressed in E.coli BL-21, and purified by the GST Sepharose 4B affinity column. The recombinant human PEDF protein was identified by Western blot and mass spectrum. The biological activity of the recombinant human PEDF protein was measured by using MTT. RESULTS: The 46 kDa recombinant human PEDF protein was obtained. It significantly inhibited the proliferation of the human umbilical vein cell line HUVEC. CONCLUSION: The recombinant human PEDF with anti-angiogenesis activity protein may be successfully purify through prokaryotic expression.