Authors:X. Feng, X. Geng, J. Peng, H. Hou, and Q. Bai
The displacement adsorption enthalpies (ΔH) of denatured α-Amylase (by 1.8 mol L−1 GuHCl) adsorbed onto a moderately hydrophobic surface (PEG-600, the end-group of polyethylene glycol) from solutions (x mol L−1 (NH4)2SO4, 0.05 mol L−1 KH2PO4, pH 7.0) at 298 K are determined by microcalorimeter. Further, entropies (ΔS), Gibbs free energies (ΔG) and the fractions of ΔH, ΔS, and ΔG for net adsorption of protein and net desorption of water are calculated in combination with adsorption isotherms of α-Amylase
based on the stoichiometric displacement theory for adsorption (SDT-A) and its thermodynamics. It is found that the displacement
adsorptions of denatured α-Amylase onto PEG-600 surface are exothermic and enthalpy driven processes, and the processes of
protein adsorption are accompanied with the hydration by which hydrogen bond form between the adsorbed protein molecules favor
formation of β-sheet and β-turn structures. The Fourier transformation infrared spectroscopy (FTIR) analysis shows that the
contents of ordered secondary structures of adsorbed α-Amylase increase with surface coverages and salt concentrations increment.
Authors:H. Bai, H. Jin, H. Fan, J. Du, F. Wang, D. Chen, and Zh. Cheng
The behavior of153Sm-EDTMP in vitro and vivo is analyzed by the size exclusion HPLC. The experimental results show that EDTMP amounts have an
obvious effect on the stability in vitro and uptake of153Sm-EDTMP in the liver. HPLC analysis of urine sample indicates that153Sm-EDTMP es excreted in the original form. The behavior in vivo of153Sm-EDTMP containing 4 μg is similar to that of153Sm-EDTMP containing 50 μg EDTMP at 1 h post-injection.
Authors:J.-J. Zhang, R.-F. Wang, S.-P. Wang, H.-M. Liu, J.-B. Li, and J.-H. Bai
The complex of [Tb2(p-ClBA)6(PHEN)2] [(p-ClBA: p-chlorobenzoate and PHEN: 1,10-phenanthroline) was prepared and characterized by elemental analysis and IR spectroscopy. The
thermal behavior of [Tb2(p-ClBA)6(PHEN)2] in dynamic nitrogen atmosphere was investigated by TG-DTG, SEM and IR techniques. By the kinetic method of processing thermal
analysis data put forward by Malek et al., it is defined that the kinetic model for the first-step thermal decomposition is SB(m,n). The activation energy E and the pre-exponential factor lnA for this step reaction are 164 kJ mol-1 and
32.80, respectively. The lifetime equation at mass loss of 10% was deduced as lnτ=(-33.0569+20512.36/T by isothermal thermogravimetric
Authors:Z. Cheng, Q. Lin, X. Jin, F. Wang, H. Bai, D. Chen, H. Fan, and J. Du
DTPA-Octreotide(Pentetreotide), a somatostatin analogue which can bind specifically and with high affinity to somatostatin
receptor in vitro and vivo, labeled with99mTc by tin reduction in acetate buffer, has been characterized by Reverse-phase High performance Liquid Chromatography. The
effect of different solvents, mobile phase pH, linear gradient and the injected volume on the separation efficiency was evaluated.
The results show that the separation efficiency is best using μBondapak-C18 (300×3.9 mm2), linear gradient of 40% to 80% methanol (1.0 ml/min) in 0.05M acetate buffer (pH 5.5) over a 30 min period and maintaining
for another 10 min. The labeled product is a mixture which mainly consists of five components (a, b, c, d, e) successfully
proved by HPLC. Paper chromatography is also evaluated in this paper. It may be used to determine the radiochemical purity
of the labeling product, but is not a good choice for the verification each components.
Authors:H. Bai, X. Jin, F. Wang, J. Du, Y. Liu, and D. Chen
The preparation of a cold kit was introduced in the paper, and the effective quantities of the components (Vc, HEDP and SnCl2·2H2O) in the kit were determined. At the sametime, the effects of labelling kit on the reaction time, reaction temperature and animal distribution were studied in detail. The initial animal experiment showed the high uptake in the skeletal tissue, the clearance in the blood was quick.
Authors:W.J. Chi, Z.Y. Wang, J.M. Liu, C. Zhang, Y.H. Wu, and Y.J. Bai
Nitrogen (N) is an important nutrient for plant growth and yield production, and rice grown in paddy soil mainly uses ammonium (NH4+) as its N source. Previous studies have shown that N status is tightly connected to plant defense; however, the roles of NH4+ uptake and assimilation in rice sheath blight disease response have not been studied previously. Here, we analyzed the effects of different N sources on plant defense against Rhizoctonia solani. The results indicated that rice plants grown in N-free conditions had higher resistance to sheath blight than those grown under N conditions. In greater detail, rice plants cultured with glutamine as the sole N source were more susceptible to sheath blight disease compared to the groups using NH4+ and nitrate (NO3–) as sole N sources. N deficiency severely inhibited plant growth; therefore, ammonium transporter 1;2 overexpressors (AMT1;2 OXs) were generated to test their growth and defense ability under low N conditions. AMT1;2 OXs increased N use efficiency and exhibited less susceptible symptoms to R. solani and highly induced the expression of PBZ1 compared to the wild-type controls upon infection of R. solani. Furthermore, the glutamine synthetase 1;1 (GS1;1) mutant (gs1;1) was more susceptible to R. solani infection than the wild-type control, and the genetic combination of AMT1;2 OX and gs1;1 revealed that AMT1;2 OX was less susceptible to R. solani and required GS1;1 activity. In addition, cellular NH4+ content was higher in AMT1;2 OX and gs1;1 plants, indicating that NH4+ was not directly controlling plant defense. In conclusion, the present study showed that the activation of NH4+ uptake and assimilation were required for rice resistance against sheath blight disease.
Authors:L. Wei, S.G. Bai, X.J. Hou, J.M. Li, B. Zhang, W.J. Chen, D.C. Liu, B.L. Liu, and H.G. Zhang
Among 20 awnless Tibetan wheat cultivars analyzed by SDS-PAGE, the migration rate of an HMW-GS in XM001584 and XM001593, named 1BX23*. was shown to be slightly faster than 1Bx6. and slower than Bx7. Its nucleotide sequence was isolated based on homology clones. In a phylogenetic tree of 1Bx genes, 1Bx23* was apparently clustered with 1Bx23. Compared with 1Bx23. eight single nucleotide replacements caused four single amino acid replacements in 1Bx23*. The deletion of “G” at base pair 1463 and insertion of “A” at 1509 bps induced a 42-nucleotide frame shift. “GQRQQAGQWQRPGQ” was replaced by “DKGNRQDNGNDRDK”. The new segment cannot be found in other HMW-GSs, and it is very similar to a segment found in collagen. Moreover, an 18-nucleotide deletion made 1Bx23* six amino acids shorter than 1Bx23. The cultivar XM001593 had 28 chromosomes, which signifies that it was tetraploid wheat, and that the new HMW-GS 1Bx23* cannot be used directly for breeding in common wheat.