Effect of dietary supplementation of vitamins A, D-3, E, and C on yearling rice field eel, Monopterus albus: Serum indices, gonad development, and metabolism of calcium and phosphorus

The objective of this study was to determine the effect of dietary vitamins A, D-3, E, and C on the gonad development, lipid peroxidation, and immune response of yearling rice field eel, Monopterus albus. A 6-wk feeding trial was designed according to an L-16(4(5)) orthogonal design, in which four vitamins, each at four supplementation levels, were arranged. Sixteen diets were mixed with the different vitamin levels and randomly assigned to 16 groups of fish. Increasing dietary vitamin E supplementation level significantly (P <= 0.05) increased the gonadosomatic index and lowered the serum content of malondialdehyde of rice field eel. Increasing dietary vitamin A and C levels also showed similar effect, but the differences were not statistically significant. Serum immunoglobulin M content increased significantly (P <= 0.01) as dietary vitamin C supplementation levels increased. The concentrations of calcium in bones showed significant (P <= 0.05) trend with vitamin D-3 and A supplementation levels, but the bone phosphorus content was not affected by the dietary vitamin levels.

Stress and its effect on optical properties of GaN epilayers grown on Si(111), 6H-SiC(0001), and c-plane sapphire

The stress states in unintentionally doped GaN epilayers grown on Si(111), 6H-SiC(0001), and c-plane sapphire, and their effects on optical properties of GaN films were investigated by means of room-temperature confocal micro-Raman scattering and photoluminescence techniques. Relatively large tensile stress exists in GaN epilayers grown on Si and 6H-SiC while a small compressive stress appears in the film grown on sapphire. The latter indicates effective strain relaxation in the GaN buffer layer inserted in the GaN/sapphire sample, while the 50-nm-thick AlN buffer adopted in the GaN/Si sample remains highly strained. The analysis shows that the thermal mismatch between the epilayers and the substrates plays a major role in determining the residual strain in the films. Finally, a linear coefficient of 21.1+/-3.2 meV/GPa characterizing the relationship between the luminescent bandgap and the biaxial stress of the GaN films is obtained. (C) 2003 American Institute of Physics.

delta C-13 variation of C-3 and C-4 plants across an Asian monsoon rainfall gradient in arid northwestern China

IEECAS SKLLQG

The hyper-radiosensitivity effect of human hepatoma SMMC-7721 cells exposed to low dose gamma-rays and C-12 ions

Hypersensitive response of mammalian cells in cell killing to X- and gamma-rays has been reported at doses below 1 Gy. The purpose of this study was to examine the low dose sensitivity of human hepatoma SMMC-7721 cells irradiated with Co-60 gamma-rays and 50 MeV/u C-12 ions. Experiments using gamma-rays and charged particle irradiation were performed, particularly in the low dose range from 0 to 2 Gy. The survival effect of SMMC-7721 cells was measured by means of standard clonogenic assay in conjunction with a cell sorter. The result indicates SMMC-7721 cells showed hyper-radiosensitive response at low doses and increased radio-resistance at larger single doses for the carbon ions (LET = 45.2 keV/mu m) and the gamma-rays. However, the HRS/IRR effect caused by high-LET irradiation is different from that by low-LET radiation. This might possibly be due to the difference in the mode of energy deposition by particle beam and low-LET irradiation.

Chromatographic separation and C-13 NMR characterization of aromatic diester-diacids isomers

Reverse phase high performance liquid chromatography (HPLC) was used to separate and quantify aromatic diester-diacids isomers which arise from the opening selectivity of anhydride rings towards methanol. C-13 NMR spectroscopy was a supplementary tool to characterize the isomer structure. It was found that a meta-position attack is slightly preferred in pyromellitic dianhydride (PMDA), while the preferred position of an attack in bridged dianhydrides is determined by the chemical nature (donors or accepters) of the bridged group. The stronger its electron-withdrawing abilities, the lower the probability of a meta-position attack.

H-1 and C-13 NMR studies of TTHA complexes with diamagnetic rare earth ions

TTHA complexes with diamagnetic rare earth ions (La3+, Y3+ and LU(3+)) were studied by H-1 and C-13 NMR spectroscopy. A symmetric structural model was suggested for La(TTHA) complex and an asymmetric model for Y(TTHA) and Lu(TTHA) complexes. The complex formation was dependent on the pH value of the solution. The interactions of La(TTHA) with the additional metal ions (La3+, Y3+ and Ca2+) were relatively weak, but relatively strong for that of Lu(TTHA) with the additional Lu3+.

GAS-PHASE ACETYLATION OF C-60 AND C-70 BY ION/MOLECULE REACTIONS

Gas phase reactions of C-60 and C-70 with the ion system of acetone under chemical ionization conditions have been studied. C-60 and C-70 can react with acetyl and oxonium ions, which come from self-chemical ionization of acetone, to form adduct ions. In addition, C-60 and C-70 can accept protons to produce protonated ions. C-70 is more active in the above reactions than C-60 because of its stronger gas-phase basicity. A sigma-bond between C-60 and an acyl carbon atom can be formed to produce stable acetylated C-60 ions. The above results may be relevant to the acetylation reactions of C-60 in the condensed phase.

Gas-phase Ion-molecular Reactions of C-60 and C-70 with Acetone and Quantum Chemistry Study

Gas-phase ion-molecular reactions of C-60 and C-70 with the ion system of acetone have been studied in this paper. The ions of protoned and acetylized C-60 and C-70 were formed by the reactions of C-60 and C-70 with some ions which existed in the ion system when mass spectrometer worked on chemical ionization conditions. The reactivity of C-70 is greater than that of C-60. Results of quantum chemical calculation for the adduct ions showed a sigma bond between the acyl carbon atom and C-60 may be Formed. These results will provide some valuable informations on the condense-phase acetylization of C-60.

DSC AND C-13 NMR-STUDIES OF ETHYLENE-PROPENE COPOLYMERS PREPARED BY A HIGHLY-ACTIVE AND STEREOSPECIFIC CATALYST

Ethylene-propene copolymers (EPR) were synthesized at different feed compositions using a highly active and isospecific MgCl2-supported Ti-based catalyst. The thermal behavior of EPR was studied by differential scanning calorimetry, the heterogeneity by f

LABORATORY HYBRIDIZATION BETWEEN CRASSOSTREA ARIAKENSIS AND C. SIKAMEA

TO understand possible reproductive interaction between Crassostrea ariakensis (Fujita, 1913) and C. sikamea (Amemiya, 1928), which coexist ill estuaries of China and Japan, we conducted 2 X 2 factorial crosses between the two species. Asymmetry in fertilization success was observed where C. sikamea eggs can be fertilized be C. ariakensis the receprocal cross resulted in no fertilization. Fertilization Success ill C.sikamea female X C. ariakemvis male (SA) crosses was lower than that in the two intraspecific crosses and produced larvae that had similar growth the rate as their maternal species during the first nine days because of maternal effects. After that, genome incompatibility casted negative effects on the growth and survival of the hybrid larvae. Most hybrid larvae died during metamorphosis. but a small number of spat survived. Genetic analysis revealed that the survived SA spat contained DNA from both species and were the hybried. This study demonstrates that hybridization between C. ariakensis and C. sikamea is possible in one direction.

Na-23, Si-29, and C-13 MAS NMR investigation of glass-forming reactions between Na2CO3 and SiO2

Winter, Rudolf; Jones, A.R.; Greaves, G.N.; Smith, I.H., (2005) 'Na-23, Si-29, and C-13 MAS NMR investigation of glass-forming reactions between Na2CO3 and SiO2', Journal of Physical Chemistry B 109(49) pp.23154-23161 RAE2008

Structural manifestation of the delocalization error of density functional approximations: C(4N+2) rings and C(20) bowl, cage, and ring isomers.

The ground state structure of C(4N+2) rings is believed to exhibit a geometric transition from angle alternation (N < or = 2) to bond alternation (N > 2). All previous density functional theory (DFT) studies on these molecules have failed to reproduce this behavior by predicting either that the transition occurs at too large a ring size, or that the transition leads to a higher symmetry cumulene. Employing the recently proposed perspective of delocalization error within DFT we rationalize this failure of common density functional approximations (DFAs) and present calculations with the rCAM-B3LYP exchange-correlation functional that show an angle-to-bond-alternation transition between C(10) and C(14). The behavior exemplified here manifests itself more generally as the well known tendency of DFAs to bias toward delocalized electron distributions as favored by Huckel aromaticity, of which the C(4N+2) rings provide a quintessential example. Additional examples are the relative energies of the C(20) bowl, cage, and ring isomers; we show that the results from functionals with minimal delocalization error are in good agreement with CCSD(T) results, in contrast to other commonly used DFAs. An unbiased DFT treatment of electron delocalization is a key for reliable prediction of relative stability and hence the structures of complex molecules where many structure stabilization mechanisms exist.