In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride (TAME) and adenosine-5'-triphosphate (ATP) have been reported. Fluorescence spectrophotom...In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride (TAME) and adenosine-5'-triphosphate (ATP) have been reported. Fluorescence spectrophotometry and Fourier transform infrared (FT-IR) spectroscopy were used to investigate this kind of weak interaction. In fluorescence experiments, obvious fluorescence quenching phenomena were observed when TAME was added, which indicated the weak interactions between TAME and ATP. It has been identified by fluorescence titration experiments that TAME exhibited high selectivity to ATP over ADP and AMP. FT-IR spectral results showed that an ATP-TAME adduct was formed. The experimental results indicated that the interaction sites were the guanidinium group of TAME main-chain and the γ-phosphate group of ATP, and the interaction took place through hydrogen bonding and electrostatic force. In addition, the effects of metal ions on the weak interaction between ATP and TAME, or between ATP and analogues of L-arginine were studied.展开更多
固定水胶比为0.24,通过I级粉煤灰替代砂浆中30%~70%水泥的强度试验,研究了Na 2 SO 4对粉煤灰-水泥砂浆体系的激发效果。结果表明:不掺激发剂时,砂浆抗压和抗折强度随粉煤灰替代率的增加成比例下降,且粉煤灰替代率达50%以上时对强度增长...固定水胶比为0.24,通过I级粉煤灰替代砂浆中30%~70%水泥的强度试验,研究了Na 2 SO 4对粉煤灰-水泥砂浆体系的激发效果。结果表明:不掺激发剂时,砂浆抗压和抗折强度随粉煤灰替代率的增加成比例下降,且粉煤灰替代率达50%以上时对强度增长速率有显著提升作用。粉煤灰替代率不低于50%时,1%的Na 2 SO 4掺量对砂浆抗压强度增进效果最佳,与此不同的是,Na 2 SO 4掺量越高,对砂浆抗折强度的增长越有利。随龄期增长,Na 2 SO 4激发粉煤灰-水泥砂浆的折压比显著下降,但抗折强度均在5.0 MPa以上。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 90210027).Acknowledgments The authors especially thank Zhide Hu in Lanzhou University for kindly allowing the use of the RF-5301PC spectrofluorophotometer (Shimadzu) in this work and Wenying He in Lanzhou University for active discussion as well as zealous help during the fluorescence experiments.
文摘In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride (TAME) and adenosine-5'-triphosphate (ATP) have been reported. Fluorescence spectrophotometry and Fourier transform infrared (FT-IR) spectroscopy were used to investigate this kind of weak interaction. In fluorescence experiments, obvious fluorescence quenching phenomena were observed when TAME was added, which indicated the weak interactions between TAME and ATP. It has been identified by fluorescence titration experiments that TAME exhibited high selectivity to ATP over ADP and AMP. FT-IR spectral results showed that an ATP-TAME adduct was formed. The experimental results indicated that the interaction sites were the guanidinium group of TAME main-chain and the γ-phosphate group of ATP, and the interaction took place through hydrogen bonding and electrostatic force. In addition, the effects of metal ions on the weak interaction between ATP and TAME, or between ATP and analogues of L-arginine were studied.
文摘固定水胶比为0.24,通过I级粉煤灰替代砂浆中30%~70%水泥的强度试验,研究了Na 2 SO 4对粉煤灰-水泥砂浆体系的激发效果。结果表明:不掺激发剂时,砂浆抗压和抗折强度随粉煤灰替代率的增加成比例下降,且粉煤灰替代率达50%以上时对强度增长速率有显著提升作用。粉煤灰替代率不低于50%时,1%的Na 2 SO 4掺量对砂浆抗压强度增进效果最佳,与此不同的是,Na 2 SO 4掺量越高,对砂浆抗折强度的增长越有利。随龄期增长,Na 2 SO 4激发粉煤灰-水泥砂浆的折压比显著下降,但抗折强度均在5.0 MPa以上。