Authors:Z. Dang, L. Fan, Y. Shen, C. Nan, and S. Zhao
Different scanning calorimetry and dynamic mechanical analysis are used to study the thermal behavior of composites by melt-mixing
low-density polyethylene (LDPE) matrix and zinc oxide whisker (ZnOw) fillers. Micrographs of the composites illustrate that needle or wedge shaped ZnOw are distributed uniformly in the LDPE matrix. Dielectric properties of the composites are measured in a frequency range of
1-10 MHZ. The results show that the addition of ZnOw does not affect the melting behavior of LDPE, but has an important effect on the heat of fusion, dynamic mechanical behavior,
and dielectric behavior of the composites.
Authors:S. Song, Y. Tao, L. Zhao, P. Liu, and Y. Wu
Barley yellow dwarf virus-GAV (BYDV-GAV) is one of the most serious viruses on wheat in China. In this study, five BYDV-GAV isolates collected from five regions in Northwestern China were sequenced. The complete genome sequences generated in this study along with nine genome sequences of BYDV-GAV isolates available in GeneBank were compared and analyzed. The comparative analysis indicated that the complete genomes of BYDV-GAV showed a low level of genetic diversity with nucleotide sequence identities ranging between 97.0% and 99.7%, and the RNA-dependent RNA polymerase gene (ORF1 + ORF2) was the most variable within the complete genome. Phylogenetic analysis indicated that the BYDV-GAV isolates in Northwestern China could be divided into two groups. In addition, two potential recombination events were detected among the 14 BYDV-GAV isolates. This study provided a detailed description of molecular characterization of BYDV-GAV in Northwestern China based on the complete genome sequences, which increased the understanding of genetic diversity of barley yellow dwarf viruses.
Authors:Y. Takizawa, L. Zhao, M. Yamamoto, T. Abe, and K. Ueno
To determine the levels of210Pb and210Po in human tissues of people in Japan, various tissue samples were obtained at autopsy from the cadavers of 22 oncologic cases, mainly in Niigata Prefecture in northern Japan, from 1986 to 1988.Wet ashing, followed by electrochemical deposition and alpha spectrometry were used to separate and determine the210Pb and210Po present. Among the tissues analyzed, the highest concentrations of210Pb and210Po were observed in bone (sternum), liver, and kidneys. The total body burden of210Pb and210Po was found to be approximately 427 pCi and 514 pCi, respectively. This estimated210Po value did not differ significantly from values found in populations in the U.S.A. and European countries.
Authors:L. Yang, S. Qiu, F. Xu, L. Sun, Z. Zhao, J. Liang, and C. Song
The effects of Amoxicillin Sodium and Cefuroxime Sodium on the growth of E. coli DH5α were investigated by microcalorimetry. The metabolic power-time curves of E. coli DH5α growth were determined by using a TAM air isothermal microcalorimeter at 37�C. By evaluation of the obtained parameters,
such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (Pm) and the time of the maximum heat power (tm), one found that the inhibitory activity of Amoxicillin Sodium vs. E. coli DH5α is enhanced with the increasing of the Amoxicillin Sodium concentration, and the Cefuroxime Sodium has a stimulatory effect on the E. coli DH5α growth when the concentration is about 1 μg mL−1. The IC50 for the Amoxicillin Sodium and the Cefuroxime Sodium are 1.6 and 2.0 μg mL−1, respectively, it implicates that the E. coli DH5α is more sensitive to Amoxicillin Sodium than Cefuroxime Sodium.
Authors:L. Lv, L. Zhao, X. Wang, H. Zhang, Z. Zhu, Y. Chai, and G. Zhang
Epimedium pubescens Maxim. and Epimedium koreanum Nakai. are two common and confused species of Herba Epimedii in Chinese Pharmacopoeia 2010 edition. Different species and growing conditions lead to chemical differences between the two species which may result in the improper clinical usage. In this work, a new method based on rapid-resolution liquid chromatography combined with time-of-flight mass spectrometry (RRLC/TOFMS) has been developed for identification and differentiation of major flavonoids in two kinds of Epimedium extract and rat plasma. The compounds were identified effectively based on the accurate extract masses and formulae acquired by RRLC/TOFMS. The fragmentation rules deduced by collision-induced dissociation (CID) were successfully implemented in distinguishing some of the isomers, further validating the results. By using the combined analytical techniques, a total of 40 major flavonoids in extracts of two kinds of Epimedium were identified within 30 min, including 31 common components and 9 characteristic components. After oral administration, three prototype compounds in rat plasma were detected by comparing the constituents measured in vitro with those in vivo, and five metabolites were identified by contrasting the fragmentation rules. The identification and structural elucidation of the chemical constituents provided essential data for further pharmacological and clinical studies on different species of Epimedium.
Authors:L. Yang, F. Xu, L. Sun, Z. Tan, H. Tan, Z. Zhao, and J. Liang
technique based on the bacterial heat output was applied to evaluate the influence
of antibiotics PIP (Piperacillin Sodium)
and composite preparation of PIP and SBT (Sulbactam
Sodium) on the growth of E. coli
DH5α. The power–time curves of the growth metabolism of E. coli DH5α were studied using a TAM Air Isothermal
Microcalorimeter at 37C. By analyzing the power–time curves, the
parameters such as growth rate constants (k),
inhibitory ratio (I), the maximum heat
power (Pm) and the
time of the maximum heat power (tm)
were obtained. The results show that different concentrations of antibiotics
affect the growth metabolism of E. coli
DH5α. The PIP in the concentration range of 0–0.05 g mL–1
has a stimulatory effect on the E. coli
DH5α growth, while the PIP of higher concentrations (0.05 –0.25
g mL–1) can inhibit its growth. It seems
that the composite preparation composed of PIP and SBT cannot improve the
inhibitory effect on E. coli DH5α
as compared with the PIP.
Authors:L. Yang, Li Sun, Fen Xu, J. Zhang, J. Zhao, Z. Zhao, C. Song, R. Wu, and Riko Ozao
The microcalorimetric method has been used to study the effects of cefpiramide and ceftizoxime sodium on the E. coli growth. The results revealed that these two cephalosporins may alter the metabolic way of the E. coli. Moreover, the lethal doses of cefpiramide and ceftizoxime sodium are 2.000 and 0.2000 μg mL−1, respectively. Combining with the relationships between growth rate constant (k), the maximum power output (Pm), the time corresponding to the maximum power output (tm) and cephalosporins concentration (C), one can draw the conclusion that the ceftizoxime sodium has a stronger inhibition effects on the growth of E. coli than that of cefpiramide and they both have the possibility to induce the drug fever.
Authors:H.Q. Zhao, L. Wang, J. Hong, X.Y. Zhao, X.H. Yu, L. Sheng, C.Z. Hang, Y. Zhao, A.A. Lin, W.H. Si, and F.S. Hong
Salt stress impaired Mn imbalance and resulted in accumulation of ROS, and caused oxidative stress to plants. However, very little is known about the oxidative damage of maize roots caused by exposure to a combination of both salt stress and Mn deprivation. Thus the main aim of this study was to determine the effects of a combination of salt stress and Mn deprivation on antioxidative defense system in maize roots. Maize plants were cultivated in Hoagland’s media. They were subjected to 80 mM NaCl administered in the Mn-present Hoagland’s or Mn-deficient Hoagland’s media for 14 days. The findings indicated that the growth and root activity of maize seedlings cultivated in a combination of both salt stress and Mn deprivation were significantly inhibited; the compatible solute accumulation, malondialdehyde, carbonyl, 8-OHdG, and ROS were higher than those of the individual salt stress or Mn deprivation as expected. Nevertheless, the antioxidative enzymes such as superoxide dismutase, ascorbate peroxidase, glutathione reductase, glutathione-S-transferase and antioxidants such as ascorbic acid, glutathione and thiol were lower than those of the individual salt stress or Mn deprivation. In view of the fact that salt stress impaired Mn nutrition of maize seedlings, the findings suggested that Mn deprivation at the cellular level may be a contributory factor to salt-induced oxidative stress and related oxidative damage of maize roots.
Authors:L. Zhou, S. Wen, J. Zhao, B. Yu, B. Han, and Ch. Yang
The -ray spectra of188Re decay have been studied by using two Ge/Li/ spectrometers and a three parameters /E-E-T/ List coincidence system. The energies and relative intensities of 52 -rays and cascade relations of 14 -rays are determined. Ten new -rays: 155 /633–478/, 984, 1096, 1463, 1332, 1530, 1574, 1810, 1867, and 1937 keV have been identified. The 155 /633–478/ transition is confirmed and its relative intensity is estimated by means of coincidence experiment. 24 levels of188Re are assigned. Among those, 6 levels are first put into the decay scheme of188Re. In addition to 1443 keV and 1937 keV levels, 1685, 1729 and 1965 keV levels are also observed in the decay of188Ir and other reaction studies. The 1948 level is recently suggested in the190Os/p, t/188Os reaction. The 486 keV and 811 keV -transitions are also put into the level scheme of188Re. The
– decay branching ratio is deduced.
Authors:J. Yi, F. Zhao, S. Xu, L. Zhang, X. Ren, H. Gao, and R. Hu
The decomposition reaction kinetics of the double-base (DB) propellant (No. TG0701) composed of the mixed ester of triethyleneglycol
dinitrate (TEGDN) and nitroglycerin (NG) and nitrocellulose (NC) with cerium(III) citrate (CIT-Ce) as a combustion catalyst
was investigated by high-pressure differential scanning calorimetry (PDSC) under flowing nitrogen gas conditions.
The results show that pressure (2 MPa) can decrease the peak temperature and increase the decomposition heat, and also can
change the mechanism function of the exothermal decomposition reaction of the DB gun propellant under 0.1 MPa; CIT-Ce can
decrease the apparent activation energy of the DB gun propellant by about 35 kJ mol−1 under low pressure, but it can not display the effect under high pressure; CIT-Ce can not change the decomposition reaction
mechanism function under a pressure.