Authors:L. Wang, Z. Tan, S. Meng, D. Liang, S. Ji, and Z. Hei
Fe–B ultrafine amorphous alloy particles (UFAAP) were prepared by chemical reduction of Fe3+ with NaBHO4 and confirmed to be ultrafine amorphous particles by transmission electron microscopy and X-ray diffraction. The specific
heat of the sample was measured by a high precision adiabatic calorimeter, and a differential scanning calorimeter was used
for thermal stability analysis. A topological structure of Fe-B atoms is proposed to explain two crystallization peaks and
a melting peak observed at T=600, 868 and 1645 K, respectively.
Authors:M.-H. Wang, Z.-C. Tan, Q. Shi, L.-X. Sun, and T. Zhang
heat capacities of 2-benzoylpyridine were measured with an automated adiabatic
calorimeter over the temperature range from 80 to 340 K. The melting point,
molar enthalpy, ΔfusHm,
and entropy, ΔfusSm,
of fusion of this compound were determined to be 316.49±0.04 K, 20.91±0.03
kJ mol–1 and 66.07±0.05 J mol–1
K–1, respectively. The purity of the compound
was calculated to be 99.60 mol% by using the fractional melting technique.
The thermodynamic functions (HT–H298.15) and (ST–S298.15) were calculated based
on the heat capacity measurements in the temperature range of 80–340
K with an interval of 5 K. The thermal properties of the compound were further
investigated by differential scanning calorimetry (DSC). From the DSC curve,
the temperature corresponding to the maximum evaporation rate, the molar enthalpy
and entropy of evaporation were determined to be 556.3±0.1 K, 51.3±0.2
kJ mol–1 and 92.2±0.4 J K–1
mol–1, respectively, under the experimental
Authors:F. Wang, H. Fan, D. Chen, H. Bai, Z. Chen, and L. Xiao
Radiolabeled somatostatin analogue is a useful ligand for scintigraphic imaging of somatostatin receptor-bearing tumors. In
this study, we investigated the effects of different radiolabeling conditions on labeling yield and ratio between mono-iodinated
and di-iodinated125I-Tyr3-octreotide by HPLC analysis. In vitro and in vivo stabilities of125I-Tyr3-octreotide and111In-DTPA-D-Phe1-octreotide were also determined. Both radiolabeled compounds were relatively stable in vitro, but were decomposed to free125I− and111In-DTPA in vivo, respectively.
Authors:W.Y. Gao, Y.W. Wang, L.M. Dong, and Z.W. Yu1
A microcalorimeter (Setaram c-80) was used
to study the thermokinetics of the hydration process of calcium phosphate
cement (CPC), a biocompatible biomaterial used in bone repair. The hydration
enthalpy was determined to be 35.8 J g–1
at 37.0°C when up to 80 mg CPC was dissolved in 2 mL of citric buffer.
In the present study, parameters related to time constants of the calorimeter
were obtained by fitting the recorded thermal curves with the function θ=Ae–?t(1– e–?2t).
The real thermogenetic curves were then retrieved with Tian function and the
transformation rate of the hydration process of CPC was found to follow the
The microstructures of the hydrated CPC were examined by scanning electron
microscopy. The nano-scale flake microstructures are due to crystallization
of calcium phosphate and they could contribute to the good biocompatibility
and high bioactivity.
Authors:G.W. Shu, D.L. Ma, H. Chen, J.P. Meng, Y. Wang, and N. Xin
The present study was to evaluate the survival rate of free and encapsulated Bifidobacterium bifidum BB28 under simulated gastrointestinal conditions and its stability during storage. Results showed that non-microencapsulated Bifidobacterium bifidum BB28 was more susceptible to simulated gastrointestinal conditions than microencapsulated bacteria. Microencapsulated Bifidobacterium BB28 exhibited a lower population reduction than free cells during exposure to simulated gastrointestinal conditions, the viable count of monolayer microcapsules, double layer microcapsules, and triple layer microcapsules decreased by nine magnitudes, four magnitudes, and one magnitude after 2 h, respectively. The enteric test showed that the microorganism cells were released from the monolayer, double layer, and triple layer microcapsules completely in 40 min. Moreover, the optimum storage times of free Bifidobacterium BB28, monolayer microcapsules, double layer microcapsules, and triple layer microcapsules were 21 days, 21 days, 28 days, and more than 35 days in orange juice, pure milk, and nutrition Express (a commercially available milk based drink), and the viable counts were maintained at 1×106 CFU g−1 or more, which means that the double layer and triple layer of microcapsules of B. bifidum BB28 have great potential in food application.
Authors:Z. Wang, L. Láng, A. Uhrin, O. Veisz, S. Liu, and G. Vida
The presence and frequency of the resistance gene complex
was investigated in the wheat breeding programme of the Agricultural Research Institute, Martonvásár, Hungary. A total of 226 wheat cultivars and advanced lines from Hungary and other countries were tested with an STS marker,
, to understand the distribution of the
resistance gene complex. A 150-bp PCR fragment was amplified in 64 wheat cultivars and lines with the resistance genes
, while a 229-bp fragment was detected in 162 genotypes without
. The genotypes with
accounted for 28.3% of the wheat cultivars and advanced lines tested. Among the 128 varieties and breeding lines of Martonvásár origin tested, 34 carried the
genes, with a frequency of 26.6%. The frequency of these genes was 30.6% in genotypes of other origin. The STS marker
could be used as an effective tool for the marker-assisted selection of
genes in breeding wheat cultivars with durable rust resistance.
Authors:F. Zhang, J. Li, X.L. Wang, W. Mao, H. Zhang, J. Guo, and J.W. Li
An allometric analysis of biomass and N mass allocation of rice (Oryza sativa L.) seedlings under non-shaded (100% of full sunlight) and shaded (30% of full sunlight) treatments were conducted. The allometric slopes and the intercepts were estimated using standardized major axis regression. Results indicated that biomass was preferentially allocated to stems during plant ontogeny, and leaves and roots were isometric when rice seedlings were not shaded. Under shade, however, more biomass was allocated to leaves and stems. N mass allocation was also altered by shading in that more N mass was allocated to the aerial shoots, and plants accumulated less N mass when shaded. Our study revealed that both biomass and N mass were in accordance with the optimal partitioning theory.
Authors:S. Xiu, H. K. Rojanala, A. Shahbazi, E. H. Fini, and L. Wang
Pyrolysis and combustion characteristics of bio-oil derived from swine manure were investigated using thermogravimetry techniques. Thermogravimetric analysis of the bio-oils were carried out in O2 and N2 atmosphere under different heating rates (5–20 °C/min) to a maximum temperature of 900 °C. The results indicate that the combustion processes of bio-oil occurred in three stages, namely the water and the lighter compound evaporation, i.e., the release of the volatile compounds, ignition and burning of the heavier compounds (mainly carbon), and finally decomposition of the carbonate compounds. The effect of heating rate was also studied, and higher heating rates were found to facilitate the combustion process. Different reaction kinetic mechanisms were used to treat TG data, and showed that diffusion models are the best fit for describing the combustion of bio-oil in air. The kinetic parameters of the three stages were determined using Coats–Redfern method. The study provided reliable basic data for the burning of bio-oil.
Authors:Z. Wang, M. Lv, D. Li, Z. Zhou, L. Zhang, and W. Yang
A new HPLC method has been established for determination of 3-monoiodotyrosine (MIT), 3,5-diiodotyrosine (DIT), 3,5-diiodothyronine (T2), 3,3′,5-triiodothyronine (T3), 3,3′,5′-triiodothyronine (rT3), and thyroxine (T4) produced by hydrolysis of iodinated casein with barium hydroxide. The hydrolytic stability of each analyte was evaluated. Iodinated casein was hydrolyzed with saturated barium hydroxide solution for 16 h at 110°C and the barium ions were then removed as barium sulfate. Reversed-phase HPLC was performed on a 2.1 mm × 150 mm, 5 μm particle, C18 column with a mixture of acetonitrile and 0.1% (v/v) formic acid as mobile phase at a flow rate of 0.2 mL min–1. Acetonitrile was maintained at 5% (v/v) for 5 min and then increased linearly to 50% (v/v) within 35 min. All analytes were quantified by measuring the absorbance at 280 nm. Validation data indicated the method was linear, with regression coefficients (R2) > 0.998, in the concentration ranges investigated. Sensitivity was adequate—limits of detection (LOD) were 0.04–0.38 μg mL–1 and limits of quantification (LOQ) were 0.05–0.38 μg mL–1. Accuracy and precision were acceptable — for all the analytes recovery was 82.0–93.0% and repeatability, as relative standard deviation, was 1.0–3.0%. Hydrolytic stability tests indicated MIT and DIT are much more stable than the other analytes. rT3 was not released directly from iodinated casein but was formed by deiodination of T4 during hydrolysis. The method could be used to identify iodinated casein, to evaluate its activity and quality, and for supervision and regulation of feed additives.