, wheref(n) is the characteristic function of square-full integers. A formula is proved that can be used to obtain better upper bound estimate for ?(x). We get ?(x)=O(x5/33+e), which improves the exponent 11/72 obtained by R. Blasubramania and K. Ramachandra.
Authors:X. Cao, Z. Wang, X. Yang, Y. Liu, and C. Wang
The kinetics of protein thermal transition is of a significant interest from the standpoint of medical treatment. The effect
of sucrose (0–15 mass%) on bovine serum albumin denatured aggregation kinetics at high concentration was studied by the iso-conversional
method and the master plots method using differential scanning calorimetry. The observed aggregation was irreversible and
conformed to the simple order reaction. The denaturation temperature (Tm), the kinetic triplets all increased as the sucrose concentration increased, which indicated the remarkable stabilization
effect of sucrose. The study purpose is to provide new opportunities in exploring aggregation kinetics mechanisms in the presence
Authors:X. Cao, X. Yang, J. Shi, Y. Liu, and C. Wang
The effect of glucose (0–15 mass%) on the kinetics of bovine serum albumin (BSA) denatured aggregation at high concentration
in aqueous solution has been studied by differential scanning calorimetry. The observed denatured aggregation process was
irreversible and could be characterized by a denaturation temperature (Tm), apparent activation energy (Ea), the approximate order of reaction, and pre-exponential factor (A). As the glucose concentration increased from 0 to 15 mass%, Tm increased, Ea also increased from 514.59409±6.61489 to 548.48611±7.81302 kJ mol−1, and A/s−1 increased from 1.24239E79 to 5.59975E83. The stabilization increased with an increasing concentration of glucose, which was
attributed to its ability to alter protein denatured aggregation kinetics.
The kinetic analysis was carried out using a composite procedure involving the iso-conversional method and the master plots
method. The iso-conversional method indicated that denatured aggregation of BSA in the presence and absence of glucose should
conform to single reaction model. The master plots method suggested that the simple order reaction model best describe the
process. This study shows the combination of iso-conversional method and the master plots method can be used to quantitatively
model the denatured aggregation mechanism of the BSA in the presence and absence of glucose.
Authors:X. Yang, X. Tian, W. Gale, Y. Cao, X. Lu, and A. Zhao
Three field experiments were conducted to determine the effect of soil Zn, foliar Zn, and soil N application on Zn and phytic acid concentrations in wheat grain grown on potentially Zn-deficient soil. Results showed significant genotypic variation in grain Zn concentrations among fifteen wheat cultivars commonly grown in northwest China. Soil Zn application had mixed effects, increasing grain Zn concentrations of some cultivars by as much as 21%, but reducing grain Zn concentrations of other cultivars by as much as 14%. In comparison, foliar Zn application increased grain Zn concentrations by 26 to 115%. Grain Zn concentrations were 14% larger in the combined (foliar Zn + soil Zn) treatment compared to the foliar Zn treatment, but the added cost of soil Zn application may not be economically justifiable. Wheat grain phytic acid concentrations and phytic acid: Zn molar ratios were less in the foliar Zn and (foliar Zn + soil Zn) treatments compared to the soil Zn and the unfertilized treatments. This indicated that foliar Zn increased Zn bioavailability. Best results were obtained when foliar Zn was applied at early grain filling. Overall, these findings indicate that foliar Zn application to Zn-efficient cultivars could reduce human Zn deficiency in regions with potentially Zn-deficient soil.
Authors:Z. Chen, S. Wang, J. Tang, X. Li, C. Liu, X. Xu, and G. Cao
To provide a convenient and facile method to evaluate the radiochemical purity (RCP) of 99mTc-TRODAT-1 in quality control of routine clinical application, a simplified method of single-strip thin layer chromatography
(TLC) was developed and validated by high performance liquid chromatography (HPLC). The RCP data of TLC correlated well with
Authors:Y. Duan, J. Li, X. Yang, X. Cao, L. Hu, Z. Wang, Y. Liu, and C. Wang
The thermal decomposition of strontium acetate hemihydrate has been studied by TG-DTA/DSC and TG coupled with Fourier transform
infrared spectroscopy (FTIR) under non-isothermal conditions in nitrogen gas from ambient temperature to 600°C. The TG-DTA/DSC
experiments indicate the decomposition goes mainly through two steps: the dehydration and the subsequent decomposition of
anhydrous strontium acetate into strontium carbonate. TG-FTIR analysis of the evolved products from the non-oxidative thermal
degradation indicates mainly the release of water, acetone and carbon dioxide. The model-free isoconversional methods are
employed to calculate the Ea of both steps at different conversion α from 0.1 to 0.9 with increment of 0.05. The relative constant apparent Ea values during dehydration (0.5<α<0.9) of strontium acetate hemihydrate and decomposition of anhydrous strontium acetate (0.5<α<0.9)
suggest that the simplex reactions involved in the corresponding thermal events. The most probable kinetic models during dehydration
and decomposition have been estimated by means of the master plots method.
Authors:J. Zeng, Z. Cao, D. Yang, F. Xu, L. Sun, L. Zhang, and X. Zhang
A series of PA-TD mixtures were prepared and their thermal properties were studied by DSC and thermal conductivity measurement.
The phase diagram of the binary system was constructed, which showed an eutectic behavior for the solid-liquid equilibrium
line. The eutectic composition of the binary system was at the mass fraction of TD near 0.7 with an eutectic temperature of
about 29°C. At TD side, PA was partially miscible in the TD solid matrix and the solid phase transition of TD had an effect
on the solidus line. The eutectic composition mixture could be viewed as a new phase change material with large thermal energy
Authors:J. Zeng, Z. Cao, D. Yang, F. Xu, L. Sun, X. Zhang, and L. Zhang
The effects of multi-walled carbon nanotubes (MWNTs) on the phase change enthalpy (ΔH) and the thermal conductivity (κ) of a solid-liquid phase change materials (PCM), palmitic acid (PA), have been investigated.
The results showed that both the ΔH and the κ of the composite were lower than that of PA when the loading of MWNTs was small. As the concentration of MWNTs
in the composites increased, the ΔH of the composites was slightly improved and then decreased linearly. However, the κ of the composites was monotonously increased
from the minimum value. When the loading of MWNTs increased to 5% and no surfactant was added, the κ of the composite was
enhanced to be 26% higher than that of PA. The κ of the composite could be enhanced by CTAB instead of SDBS when the loading
of MWNTs was small, as SDBS showed no obvious effect on the κ of the composites. Furthermore, the effects of surface modification
of MWNTs on the ΔH and the κ of the composites have also been investigated.
Authors:J. Wang, M. Liu, X. Tong, W. Peng, H. Cao, and W. Su
Shenqi Fuzheng Injection (SFI) is a traditional Chinese medicine injection, widely used to enhance immune function of clinical cancer patients undergoing chemotherapy. In this study, a high-performance liquid chromatography-diode array detection-evaporative light scattering detection (HPLC-DAD-ELSD) method was established for quality control of SFI, which could simultaneously semiquantitatively reflect the constituents displayed in the chromatographic profile of SFI. The relative retention time and relative peak areas of the 21 common peaks related to the reference peak were calculated. The validity and advantage of this method were validated by systematically comparing chromatograms of 10 batches of SFI samples with the analytical methods of principal component analysis and angle cosine method recommended by the State Food and Drug Administration of China. Moreover, a total of 21 constituents of SFI were identified or tentatively characterized in the fingerprint via ultrafast liquid chromatography-diode array detection-quadrupole time-of-flight (UFLC-DAD-Q-TOF) tandem mass spectrometry technique on the basis of the retention time, ultraviolet spectra, fragmentation patterns, and reported literatures. All the results proved that the technique was useful in comprehensive quality evaluation of SFI and further study.