http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
( Yan Xin ),( Zhibin Sun ),( Qiongzhen Chen ),( Jue Wang ),( Yicheng Wang ),( Linfeng Luogong ),( Shuhuan Li ),( Weiliang Dong ),( Zhongli Cui ),( Yan Huang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11
A novel alkaline protease from Streptomyces sp. M30, SapHM, was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, and DEAE-Sepharose chromatography, with a yield of 15.5% and a specific activity of 29,070 U/mg. Tryptic fragments of the purified SapHM were obtained by electrospray ionization quadrupole timeof- flight mass spectrometry. Nucleotide sequence analysis revealed that the gene sapHM contained 1,179 bp, corresponding to 392 amino acids with conserved Asp156, His187, and Ser339 residues of alkaline protease. The first 24 amino acid residues were predicted to be a signal peptide, and the molecular mass of the mature peptide was 37.1 kDa based on amino acid sequences and mass spectrometry. Pure SapHM was optimally active at 80°C in 50 mM glycine-NaOH buffer (pH 9.0), and was broadly stable at 0-50°C and pH 4.0-9.0. The protease relative activity was increased in the presence of Ni2+, Mn2+, and Cu2+ to 112%, 113%, and 147% of control, respectively. Pure SapHM was also activated by dimethylformamide, dimethyl sulfoxide, Tween 80, and urea. The activity of the purified enzyme was completely inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. The Km and Vmax values were estimated to be 35.7 mg/ml, and 5 × 104 U/mg for casein. Substrate specificity analysis showed that SapH was active on casein, bovine serum albumin, and bovine serum fibrin.
Jin Zhang,Ronggui Deng,Zhibin Zhong,Peipei Wu,Shaoli Qi 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10
In high in-situ stress zones, cataclastic rocks have exerted a significant influence on the stability of engineering structures. However, the mechanical properties of cataclastic rocks can not be accurately studied due to difficulties in sampling and laboratory testing. In this paper, laterally confined compression tests for specimens that were obtained by the developed in-situ sampling devices were performed to investigate the stress states. A modified thick-walled cylinder model considering axial shear stress was introduced. The interaction mechanics model for a compressed sample and an equivalent single-layer cylinder was established. Based on the principle of elasticity, the laterally confined stress, the axial shear stress, and the axial stress of the sample were derived and obtained. Moreover, the effects of mechanical and geometric parameters of the equivalent cylinder on the force condition of the specimen were analyzed. The results show that the confined stress is positively correlated with the equivalent elastic modulus and the geometric factor. Therefore, the confined stress can be strengthened by increasing the elastic modulus, alternatively, increasing the outer diameter and decreasing the inner diameter. However, the axial stress is little affected by the equivalent elastic modulus and the geometric factor and is not affected by the equivalent Poisson's ratio. As the distance from the center height increases, the axial stress decreases linearly and the difference in axial stress becomes larger considering axial shear stress and ignoring axial shear stress.