[en] Saccharomyces cerevisiae rad9 checkpoint mutants exhibit pleiotropic phenotypes, including higher frequencies of chromosome loss, radiation sensitivity, and decreased induction of DNA damage-inducible genes. We had previously shown that rad9 mutants exhibit higher frequencies of DNA damage-associated translocations but lower frequencies of DNA damage-associated sister chromatid exchange (SCE), compared to wild type. Herein, we have shown that differences between the frequencies of DNA damage-associated recombination in the rad9 mutant and wild type depend on the identity and the concentration of the DNA damaging agent. Translocation and SCE frequencies were measured in strains containing truncated his3 fragments, located either on chromosomes II and IV, or located in tandem on chromosome IV, respectively. DNA damage-associated frequencies of translocations after exposure to hydrogen peroxide (H₂O₂), bleomycin, phleomycin, cisplatin, and camptothecin are higher in the rad9 diploid than in wild type. However, translocation frequencies after exposure to 4-nitroquinoline 1-oxide (4-NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) are similar in rad9 and wild-type strains. We suggest that the deficiency in triggering G₂ arrest after exposure to specific DNA damaging agents results in the higher levels of DNA damage-associated translocations in rad9 mutants

[en] Bone metabolism inpatients with chronic renal failure treated by continuous ambulatory peritoneal dialysis (CAPD) was evaluated. IRMA, RRA and RIA were used to detect PTH, 25 (OH)D₃, 1,25(OH)₂D₃, BGP, Ca and P levels in the blood of 24 CAPD patients. PTH and BGP were increased in uremic patients ad decreased after CAPD. 25(OH)D₃ and 1,25 (OH)₂D₃ were decreased in the patients, but their levels were not changed further after CAPD. PTH had negative correlation with 25 (OH)D₃ (r = -0.379, P < 0.05) and 1,25 (OH)₂D₃ (r = -0.451, P < 0.01). PTH had positive correlation with BGP (r 0.501, P < 0.01) in CAPD patients, and the correlativity was decreased by CAPD. The results showed: PTH hypersecretion is a main factor inducing bone metabolism disturbance, and bone turnover rate is decreased in these patients by CAPD

[en] The wavelet analysis method, used in ICT to detect edges within a cross section is introduced. Comparing with the conventional method of detecting edges from the image of ICT, this method can reduce the noise of images and can filter the non-white noise. It can also be applied in medical computerized tomography

[en] The Sino United Spherical Tokamak (SUNIST), built in 2002, is the first Tokamak device with a low aspect ratio (R/a=1.3). It has a structure of viton cross-sealing and electrical insulation. The nominal parameters are as follows: major R=30 cm, minor radius a=23 cm, natural elongation k=1.6, aspect ratio R/a=1.3, on-axis toroidal field B_T=0.15 T and plasma current I_p=50 kA. Reproducible discharge with plasma current of 52 kA has been achieved in initial ohmic heating experiments. (authors)

[en] The goal of the Sino-United Spherical Tokamak (SUNIST) at Tsinghua University is to extend the understanding of toroidal plasma physics at a low aspect ratio (R/a≅1.3) and to demonstrate a maintainable target plasma by non-inductive startup. The SUNIST device is designed to operate with up to 13 kA of ohmic heating field current, and to 0.15 T of toroidal field at 10 kA of discharge current. All of the poloidal fields can provide 30 mVs of Volt-seconds transformer. Experimental results of plasma startup show that SUNIST has remarkable characteristics of high ramp rate (dI_P/dt≅50 MA/s), high normalized current I_N of about 2.8 (I_N=I_P/aB_T), and high-efficiency (I_P/I_ROD≅0.4) production of plasma current while operating at a low toroidal field. Major disruption phenomena have not been observed from magnetic diagnostics of all testing shots. Initial discharges with 52 kA of plasma current (exceeding the designed value of 50 kA), 2 ms of pulse length and 50 MA/s of ramp rate have been achieved easily with pre-ionized filament

[en] Measurements of the density perturbation induced by the sinusoidal modulation of gas puff injection have been performed in the HL-1M plasma. The particle transport equations have been analyzed by using a simplified numerical method. The measuring results and the calculated ones have been compared with each other. The particle diffusion coefficients in the core region were evaluated to be 0.2 +- 0.1 m²·s^-1, and those in the edge region 1.0 +- 0.2 m²·s^-1 for ohmic plasmas

[en] Two arrays of Mirnov coils and a pair of concentric loops have been installed to superconducting tokamak HT-7. Software compensation and digital Fourier series expansion are the two techniques that have been applied successfully in measuring diamagnetic flux of concentric loops and internal inductance. The internal inductance of plasma l_i, poloidal beta β_p, Grad Shafranov parameter Λ, plasma minor radius α_p and the center of the outermost magnetic flux surface Δ_g are determined

[en] The preliminary analysis of vacuum vessel of different cross-section has been carried out with the ANSYS code. The results show that the strength of vacuum vessel of round arc cross-section is better than that of polygonal cross-section. The vacuum vessel with 8 and 16 sets of gravity support component is respectively analyzed. The distributing of gravity support components is optimized according to analysis results, thereby the thermal stress decreases during baking. (authors)

[en] Sawtooth activity on HT-7 tokamak has been investigated experimentally mainly by using soft x-ray diode array and magnetic probes. their behaviors and occurrences are correlated closely to the discharge conditions: the electron density N_e, the electron temperature T_e, the safety factor q_a on plasma boundary and wall condition etc. When central line-averaged electron density N_e-bar(0) is over 2.0 x 10¹³ cm^-3, major sawtooth activity emerges with a period of up to 6.5 ms and a fluctuation amplitude of up to 2-30% of SXR radiation signal. In some cases such as the safety factor between 4.2-4.7 and Z_eff = 3.0-6.0, a monster sawtooth activity often emerges without apparent deterioration of plasma confinement and without major disruption. During these evens, abundant MHD phenomena are observed including partial sawtooth oscillations. The observed sawtooth behaviors and their dependence on the electron density N_e and wall condition in ohmically heated plasma are introduced, the results are discussed and presented

[en] A diagnostic system of soft x-ray diode-array was set up for HT-7 superconducting tokamak. The system consists of two slot-aperture cameras and is capable of measuring the soft x-ray emission from the plasma on HT-7 device with a high resolution in space and a high response in time. Both cameras, located separately in a horizontal port and a vertical port each with thirty-seven detectors of Au-Si surface-barrier diode (SBD) can view the same toroidal cross-section of the plasma from different poloidal chords. The structure, principle and performance of the diagnostic system are described and some experimental results observed are presented