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In this paper, the hot deformation behavior of a TNM TiAl-based alloy (Ti-44.45Al-3.80Nb-1.01Mo-0.29Si-0.14B) is investigated via isothermal compression tests. The experimental results demonstrate that the critical strain for dynamic recrystallization gradually decreases with increasing deformation temperature. At the initial stage of the low-temperature deformation process, the deformation is mainly caused by dislocation glide in the γ and β phases. When the deformation reaches a certain level, dislocation glide in the β and the DRX γ phases dominates the deformation. In the high-temperature deformation process, the deformation is the result of dislocation glide in the α and β phases. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate the clinical method to remove a gutta-percha and root canal sealers. METHODS: 168 root canals which had been filled with gutta-percha were selected, all root canals needed endodontic retreatment. The root canal fillings were removed and the root canal was re-prepared with the method of desocclusol and manual mechanical method. Then the root canal was filled again with lateral condensation technique. RESULTS: With manual mechanical method and desocclusol, all original root canal fillings were removed completely. The combined method could effectively prevent the formation of step, root canal-side wear, broken equipment or other complications during the course of retreatment. The success rate of retreatment was 89.3%. CONCLUSIONS: Combined manual mechanical method with desocclusol could improve the success rate of recanalization of the root canal and saved time and effort. It is a method which could reduce the intensity and improve the efficiency of dentists, and worthy of wide clinical application. Supported by Research Fund of Department of Health of Jiangxi Province(20063127)and Jiangxi Provincial Department of Science and Technology (2008BB2860). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical method to remove a gutta-percha and root canal sealers., Methods: 168 root canals which had been filled with gutta-percha were selected,all root canals needed endodontic retreatment.The root canal fillings were removed and the root canal was re-prepared with the method of desocclusol and manual mechanical method. Then the root canal was filled again with lateral condensation technique., Results: With manual mechanical method and desocclusol,all original root canal fillings were removed completely. The combined method could effectively prevent the formation of step,root canal-side wear,broken equipment or other complications during the course of retreatment.The success rate of retreatment was 89.3%., Conclusions: Combined manual mechanical method with desocclusol could improve the success rate of recanalization of the root canal and saved time and effort. It is a method which could reduce the intensity and improve the efficiency of dentists, and worthy of wide clinical application.

Objective: To investigate whether A/G polymorphism at position 49 in exon 1 of cytotoxic T lymphocyte antigen-4 (CTLA-4) gene confers the susceptibility to unexplained recurrent spontaneous abortion in Chinese population., Methods: One hundred and sixty-eight restrictive Chinese women with unexplained recurrent spontaneous abortion (URSA) and 117 women with normal pregnancy as control were included in this study. Polymerase chain reaction restrictive fragment length polymorphism (PCR-RFLP) was used to detect the polymorphism at position 49 in exon 1 of CTLA-4 gene. The frequency of alleles G/A, genotypes AA/AG/GG and phenotypes A+ (AA + AG)/G+ (GG + AG) of CTLA-4 were compared between URSA patients and controls., Results: The different distributions of alleles G/A, genotype AA/AG/GG and phenotypes A+/G+ of CTLA-4 were observed between URSA patients and controls. The frequencies of both G allele [68.4% (230/336) vs 59.4% (139/234), P < 0.05] and GG genotype [48.8% (82/168) vs 33.3% (39/117), P < 0.05] were significantly higher in URSA group than that in control group, while the frequencies of AG genotype [39.3% (66/168) vs 52.1% (61/117), P < 0.05] and A+ (AA + AG) phenotype [51.2% (86/168) vs 66.7% (78/117), P < 0.05] were significantly lower in URSA group than that in control group., Conclusions: The results suggest that A/G polymorphism in exon-1 of CTLA-4 might confer the susceptibility to RSA in Chinese women.

The environmental DNA was directly extracted from the sediment in Parece Vela Basin, Pacific Ocean, at a depth of 5010 m. Bacterial 16S rRNA gene library of 32 clones was generated using bacterial universal primers and 16S rDNA sequences were analyzed phylogenetically. 17 phylotypes were obtained. The library was dominated by gamma-Proteobacteria, alpha-Proteobacteria and marine uncultured bacteria. Sixty-two percent of the cloned sequences was highly related to the known bacteria in the genus Halomonas, Alcanivorax, Pseudomonas, Acinetobacter, Pseudoalteromonas (> 96% sequence similarity), while some of the cloned sequences showed less affiliation with known taxa (< 94% sequence similarity) and may represent novel taxa.

An alkaline catalase has been purified and characterized from a slightly halophilic and alkaliphilic bacterium Bacillus sp. F26. The purification was performed with a four step procedure consisting of ammonium sulfate precipitation, ion exchange, gel filtration and hydrophobic interaction chromatography, and finally achieved a 58.5-fold-purifying over the crude extract. The purified catalase was composed of two identical subunits with a native molecular mass of 140 kD. The native enzyme showed the typical Soret band appearing at 408 nm. The pyridine hemochrome spectrum indicated the presence of protoheme IX as the prosthetic group. The apparent Km value for enzyme activity on H2O2 was calculated to be 32.5 mmol/L. The activity of this catalase was not reduced by dithionite but was strongly inhibited by cyanide, azide, and 3-amino-1,2,4-triazole (the specific inhibitor of monofunctional catalase). No peroxidase activity of this enzyme was detected when using o-dianisidine, diaminobenzidine (DAB) and p-phenylenediamine as electron donor. Moreover, the N-terminal sequence of this catalase exhibited substantial similarity to the monofunctional catalase subgroup rather than catalase-peroxidase or Mn-catalase one. Therefore, we characterize the purified catalase as a monofunctional catalase. Besides, this monofunctional catalase was thermosensitive and its activity exhibited pH-independent over pH 5-9 but showed a sharp maximum at pH 11. An activity half-life of approximately 49 h was measured when the enzyme was incubated at 20 degrees C and pH 11. To our knowledge, pH 11 is the most alkaline condition for optimum catalysis and enzyme stability among the catalases reported up to now. Furthermore, this monofunctional catalase also showed excellent halo-alkali-stability with a half-life of approximately 90 h at 0.5 mol/L NaCl and pH 10.5. On the other hand, so far as we know, the characterized catalase is the first dimeric monofunctional catalase from alkaliphiles and is also the first monofunctional catalase derived from a natural soda lake, which could partially reflect the oxidative stress response in the corresponding environment.

Objective: To investigate the association between the C677T and A1298C mutation of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and unexplained recurrent spontaneous abortion (URSA) in Chinese population., Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the mutation of C677T and A1298C of MTHFR in 148 cases with URSA and 82 normal controls., Results: (1) The distribution frequencies of C667T associated 3 genotypes between the URSA and control group showed statistically significant difference (P = 0.012). The frequencies of C677T genotypes were: CC (33.3%), CT (53.1%), TT (13.6%) in URSA group and CC (52.4%), CT (51.5%), TT (6.1%) in control group, respectively. And the frequency of CC genotype in URSA group was decreased significantly (P = 0.005), while the frequency of T allele in URSA was increased (P < 0.005). (2) The prevalence of the MTHFR A1298C associated 3 genotypes and A/C alleles in URSA group did not differ significantly from the control. (3) According to the linkage analysis of C677T and A1298C, 8 linkage genotypes were found, and the frequency of 677CC/1298AA in URSA was significantly lower compared with the control, the linkage of 677 (CT + TT)/1298CC was only observed in URSA group., Conclusions: The mutations of MTHFR C677T and A1298C play a role in the mechanism of unexplained recurrent spontaneous abortion.

Background: DNA analysis has shown a lack of significant compatibility between couples affected by unexplained recurrent spontaneous abortion (URSA) compared with normal fertile couples, [8] although one study that made use of a PCR-sequence-specific oligonucleotide (SSO) method did observe evidence of significant compatibility in the HLA-DQA1 and DQB1 alleles between patients and aborted fetuses. [9] This study was designed to investigate whether URSA were associated with particular DQ alleles or promoter alleles., Methods: Thirty-two patients with URSA and 54 women who had had at least one successful pregnancy were included in this study. HLA-DQ genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The HLA-DQB1 promoter was detected by the SSO and sequence-specific primer (SSP) methods. The DQA1, DQB1, and DQB1 promoter (QBP) gene frequencies in the patients were compared with the gene frequencies in normal controls. The data were analyzed statistically with the chi(2) and Fisher's exact tests., Results: The results showed that the frequency of DQB1 * 0604/0605 was significantly higher and the frequency of DQB1 * 0501/0502 was significantly lower in the patient group as compared with the normal controls. In addition, the frequencies of the DQA1 * 01-DQB1 * 0604/0605 and QBP6.2-DQB1 * 0604/0605 haplotypes were overrepresented in the patients relative to the controls. Our results did not show any differences between URSA patients and the controls with regard to DQA1 and QBP allele frequencies., Conclusions: Our data suggest that URSA is associated with the HLA-DQB1 coding region, and is not associated with its upstream regulatory region. The DQB1 * 0604/0605, DQA1 * 01-DQB1 * 0604/0605, and QBP6.2-DQB1 * 0604/0605 haplotypes may confer susceptibility to URSA, while the DQB1 * 0501/0502 allele may protect women from URSA.