GAS-PHASE ION-MOLECULE REACTIONS OF BUCKMINSTERFULLERENE C-60 WITH SOME SMALL ORGANIC-COMPOUNDS IN MASS-SPECTROMETER

In chemical ionization mass spectrometry (CIMS) gas phase C-60(+) or C-60 can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions. A dozen of gas-phase adduct ions of C-60 are observed, and most of them contain chlorine atoms. The results of the comparison and analysis show that the relative intensities of adductions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C-60(+) or C-60. This indicates that the alkene-like C-60(+) or C-60 can act as a radical sponge in addition reactions.

Sm~(3+)在玻璃中的发光以及Sb~(6+)、Ce~(6+)、Gd~(3+)对Sm~(3+)发光性质的影响

本文研究了单掺(Sm~(3+),Ce~(3+)、Gd~(3+).Sb~(3+)、双掺(Sm~(3+)+Ce~(3+)、Sm~(3+)+Gd~(3+),Sm~(3+)+Sb~(3+))和兰掺(Sm~(3+)+Gd~(3+)+Ce~(3+))约四十余种不同玻璃的发射谱和激发谱.探讨了玻璃成份和掺杂离子浓度对Sm~(3+)发光性质的影响以及Ce~(3+),Gd~(3+)、Sb~(3+)、Ce~(3+)+Gd~(3+)对Sm~(3+)的敏化作用。

富勒烯碳-60,碳-70的电化学研究进展

短短的几年,随着各种物理与化学研究方法的相继介入,以C_(60)和C_(70)为代表的富勒烯研究取得了令人瞩目的成就。跟踪最新进展,引文41篇,本文就其电化学方面的研究工作做了系统的综述。

固熔体60%NaAlSi_2O_6-40%CaMgSi_2O_6在高温高压下的相图的研究

在1.0～5.0GPa、700～1750℃条件范围内,对固熔体0.6NaAlSi_2O_6-0.4CaMgSi_2O_6进行了研究,探讨了该固熔体在高温高压下的存在行为,研究了由非晶态玻璃向翡翠转化过程中γT作用的相图,得到的透辉石翡翠的晶胞参数为α=0.9439nm,b=0.8573nm,c=0.5233nm,β=107.28°和V=0.41702nm~3。本实验中合成的宝石级翡翠为色泽温润,具有玻璃光泽,半透明的极富观赏性的透辉石翡翠。

Purification and characterization of agarases from a marine bacterium Vibrio sp. F-6

Marine bacterium Vibrio sp. F-6, utilizing agarose as a carbon source to produce agarases, was isolated from seawater samples taken from Qingdao, China. Two agarases (AG-a and AG-b) were purified to a homogeneity from the cultural supernatant of Vibrio sp. F-6 through ammonium sulfate precipitation, Q-Sepharose FF chromatography, and Sephacryl S-100 gel filtration. Molecular weights of agarases were estimated to be 54.0 kDa (AG-a) and 34.5 kDa (AG-b) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH values for AG-a and AG-b were about 7.0 and 9.0, respectively. AG-a was stable in the pH range of 4.0-9.0 and AG-b was stable in the pH range of 4.0-10.0. The optimum temperatures of AG-a and AG-b were 40 and 55 degrees C, respectively. AG-a was stable at temperature below 50 degrees C. AG-b was stable at temperature below 60 degrees C. Zn2+, Mg2+ or Ca2+ increased AG-a activity, while Mn2+, Cu2+ or Ca2+ increased AG-b activity. However, Ag+, Hg2+, Fe3+, EDTA and SDS inhibited AG-a and AG-b activities. The main hydrolysates of agarose by AG-a were neoagarotetraose and neoagarohexaose. The main hydrolysates of agarose by AG-b were neoagarooctaose and neoagarohexaose. When the mixture of AG-a and AG-b were used, agarose was mainly degraded into neoagarobiose.

Analysis of the expression and antioxidative property of a peroxiredoxin 6 from Scophthalmus maximus

Peroxiredoxins (Prxs) are a group of antioxidant proteins that protect cells from oxidative damage caused by various peroxides. To date, six different isoforms of peroxiredoxin (Prx1 to Prx6) have been identified, of which, Prx6 belongs to the 1-Cys Prx subfamily. Although Prx6 of several fish species have been reported at sequence level, there are very few documented studies on the potential function of fish Prx6. In this report, we describe the identification and analysis of a Prx6 homologue, SmPrx6, from turbot Scophthalmus maximus. The full length cDNA of SmPrx6 contains a 5'- untranslated region (UTR) of 60 bp, an open reading frame of 666 bp, and a 3'-UTR of 244 bp. The deduced amino acid sequence of SmPrx6 shares 81-87% overall identities with known fish Prx6. In silico analysis identified in SmPrx6 a conserved Prx6 catalytic motif, PVCTTE, and the catalytic triads putatively involved in peroxidase and phospholipase A2 activities. Expression of SmPrx6 was detected in most fish organs, with the highest expression levels found in blood and heart and the lowest level in spleen. Experimental challenges with bacterial pathogens and poly(I:C) upregulated SmPrx6 expression in liver and spleen in a manner that is dependent on the challenging agent and the tissue type. Treatment of cultured primary hepatocytes with H2O2 enhanced SmPrx6 expression in a dose-dependent manner. Recombinant SmPrx6 expressed in and purified from Escherichia coli exhibited thiol-dependent antioxidant activity and could protect cultured hepatocytes from H2O2-induced oxidative damage. Taken together, these results indicate that SmPrx6 is a Prx6 homologue with antioxidative property and is likely to be involved in both cellular maintenance and protective response during host immune defense against bacterial infection. (C) 2010 Elsevier Ltd. All rights reserved.

HPLC测定四川及青海地区獐牙菜植物中6种主要成分的含量

目的:建立反相高效液相色谱法同时测定四川及青海地区部分獐牙菜中獐牙菜苦苷、龙胆苦苷、芒果苷、当药醇苷、异荭草苷、1,8-二羟基-3-甲氧基(口山)酮的含量.方法:采用RP-HPLC,使用Kromasil C_(18)(4.6 mm×250mm,5 μm)柱;流动相甲醇-水(含0.02%磷酸);梯度洗脱程序为0～50 min,甲醇的体积分数(下同)由20%上升至80%;50～55 min由80%增至100%,55～60 min为100%,流速1 mL•min~(-1),检测波长254 nm;柱温35 ℃.结果:6种成分均达到基线分离,线性良好.结论:该方法快速、准确、重复性好,为该类药材的入药提供了理论依据.

栽培川西獐牙菜中6种药用成分的测定方法和动态积累研究

采用反相高效液相色谱法对川西獐牙菜中6种药用成分不同生长期的含量进行了测定.色谱柱为Kromasil C18(250 mm×4.60 mm,5 μm),流动相为甲醇-0.02%的磷酸水溶液,检测波长260 nm.该方法具有很好的线性关系和回收率.结果显示,川西獐牙菜全草的最佳采收期为9月中旬(花果期).

国产6种点地梅属植物的核型及其系统学意义

报道了点地梅属6种12个居群的染色体数目和核型。它们的染色体数目（2n）、核型公式（KF）、染色体相对长度组成（CRL）、核型不对称性系数（A. sK％）和核型类型（KT）分别为：点地梅在南京的2个居群都是2n=2x=20，KF=18m+2sm, CRL=2L+6M_2+10M_1+2S，核型KT属于1A型，但核型不对称性系数As. K％分别是55.04％和56.71％；北点地梅在内蒙古锡林郭勒和白音锡勒居群的2n=2x=20，KF分别为16m+2sm+2st+1b和16m+2sm+2st+4b，染色体相对长度组成分别是14M_2+4M_1+2S+1b和12M_2+6M_1+2S+4b，核型不对称性系数As. K％分别是57.65％和58.86％，属2A型和2B型；高原点地梅在青海玛沁县昌马河居群和兴海县温泉居群都是2n=2x=20，KF=10m+8sm+2st。但相对长度组成分别为12M_2+8M_1和4L+6M_2+6M_1+4S, As. K％分别是60.35％和62.57％，属2A型和2B型；雅江点地梅在青海玛多县巴颜喀拉山居群和大通县达坡山居群分别为2n=4x=40和20n=6x=60，KF=36m+2sm+2st和KF=46m+10sm+4st+2b, CRL=2l+20M_2+14M_1+4S和GRL=6L+30M_2+16M_1+8S+2b, As.K％分别为55.62％和58.31％，核型均属于2B；巴颜喀拉山北坡的鳞叶点地梅2n=40、60、80。西藏点地梅青湖居群中有2种细胞型：①2n=2x=24, KF=12m+6sm+6st+4b, CRL=6L+2M_2+8M_1+4S+4b, As. K％＝65.74％，核型属2B；②2n=2x=22,KF=14m+4sm(2SAT)+4st, CRL=4L+6M_2+8M_1(2SAT)+4S,As. K％=63.40％，核型也属于2B。西宁西山湾居群也有2种细胞型；①2n=3x=36, KF=36m,CRL=4L+12M_2+20M_1, As. K％=54.82％，核型属1A；②2n=3x=33,KF=33m, CRL=3L+12M_2+18M_1,As. K％=52.11％，核型属1A。点地梅属的染色体原始基数可能是x=10，在种间或种内观察到有3种核型变化：染色体非整倍性变化、多倍化和核型不对称性变化。将2倍体居群的核型和不对称性进行比较，可以看出点地梅是较对称的核型。因此，在研究的种中应是比较原始的类群。北点地梅的核型不对称性和进化程度高于点地梅而低于高原点地梅和西藏点地梅。染色体多倍化的雅江点地梅、鳞叶点地梅和西藏点地梅等在核型上也许是最进化的类群。

6-MBOA对植食性小哺乳类繁殖作用的研究进展

本文主要综述了6-MBOA 对植食性小哺乳类繁殖的作用及其信息传递的研究进展。植物组织的6-MBOA 是触发植食性小哺乳类繁殖投入时间, 调节个体繁殖性能的特定化学信号。野外和实验室的研究揭示, 植食性小哺乳类的繁殖能对植物衍生的6-MBOA 作出正的反应。在亲代母体和子代间存在6-MBOA 信息传递, 摄入6-MBOA 的母体, 能在妊娠期和哺乳期将其信息传递给子代, 子代的繁殖对母体传递的6-MBOA 信息亦能作出相应的生理反应, 其繁殖投入的时间和反应强度均依赖于母体所接受的6-MBOA , 且可超越短光照周期对子代繁殖的抑制。在变动剧烈的不可预测环境中, 兼性机会主义繁殖者, 以获得的6-MBOA 信息调整其繁殖投入。

黄土高原中部60万年来黄土—古土壤序列有机碳同位素研究

Vegetation is very sensitive to climate change. Carbon isotopes in paleosol have been widely used to contruct the propotion of plants using C3 and C4 photosynthetic pathways. δ13C of Loess organic matter were analyzed on the loess- paleosols samples from Jingchuan sections and Luochuan S4—S5 sequence. This paper presents a long carbon isotope time series, covering the last 600kyr. δ13C record of Loess organic matter in Jingchuan is correlated with marine oxygen isotope records. Basing on former research work, this paper discusses temperature, rainfall and P CO2 effect on δ13Corg value. In the interglacial periods, carbon isotope is more sensitive than other proxies and indicates several climate fluctuations. The main conclusions are as follows: 1. Obtained δ13C composition from paleosols and loess sediments in Jingchuan range of -20.0‰ to -24.6‰, the maximum biomass of C4 is 35%, indicating a C3 and C4 mixed steppe with C3 dominated. C4 plant is not always expansion during paleosols periods. The minimum values of Jingchuan section appeared in S4 soil, and the vegetation was almost pure C3 plant at that time. δ13Corg value in S5-2 is also lower than loess in S5, reaching the minimum valus of S5 soil. 2. PCO2 variation has little impact on δ13Corg value in interglacial periods for the last 600kyr. The correlation between δ13Corg value curve and magnetic susceptibility curve as proxy of summer monsoon in general, means summer monsoon drive C4 plant expansion during glacial and interglacial. 3. The lowerδ13Corg values in S4 and S5-2 appear at Jingchuan and Luochuan, suggest origin from woodland or C3 grassland. Whatever vegetation it is, indicate strengthened East Asian summer monsoon and increase of precipitation. C4 plant percentage is lower in S5-1 and S1 which have stronger summer monsoon, than S0 and S2. And it also indicates increase of precipitation.δ13Corg values has not always non-linearity correlation with summer monsoon. 4. The maximum entroy spectral analysis of δ13C values of the last 600kyr indicates there is 21 kyr cycles in Loess sequence. It means that summer monsoon in the Chinese Loess Plateau also has the precession cycles like its origin low latitude.

Physiological levels of PTEN control the size of the cellular Ins(1,3,4,5,6)P5 pool

To understand how a signaling molecule's activities are regulated, we need insight into the processes controlling the dynamic balance between its synthesis and degradation. For the Ins(1,3,4,5,6)P5 signal, this information is woefully inadequate. For example, the only known cytosolic enzyme with the capacity to degrade Ins(1,3,4,5,6)P5 is the tumour-suppressor PTEN [J.J. Caffrey, T. Darden, M.R. Wenk, S.B. Shears, FEBS Lett. 499 (2001) 6 ], but the biological relevance has been questioned by others [E.A. Orchiston, D. Bennett, N.R. Leslie, R.G. Clarke, L. Winward, C.P. Downes, S.T. Safrany, J. Biol. Chem. 279 (2004) 1116 ]. The current study emphasizes the role of physiological levels of PTEN in Ins(1,3,4,5,6)P5 homeostasis. We employed two cell models. First, we used a human U87MG glioblastoma PTEN-null cell line that hosts an ecdysone-inducible PTEN expression system. Second, the human H1299 bronchial cell line, in which PTEN is hypomorphic due to promoter methylation, has been stably transfected with physiologically relevant levels of PTEN. In both models, a novel consequence of PTEN expression was to increase Ins(1,3,4,5,6)P5 pool size by 30-40% (p<0.01); this response was wortmannin-insensitive and, therefore, independent of the PtdIns 3-kinase pathway. In U87MG cells, induction of the G129R catalytically inactive PTEN mutant did not affect Ins(1,3,4,5,6)P(5) levels. PTEN induction did not alter the expression of enzymes participating in Ins(1,3,4,5,6)P5 synthesis. Another effect of PTEN expression in U87MG cells was to decrease InsP6 levels by 13% (p<0.02). The InsP6-phosphatase, MIPP, may be responsible for the latter effect; we show that recombinant human MIPP dephosphorylates InsP6 to D/L-Ins(1,2,4,5,6)P5, levels of which increased 60% (p<0.05) following PTEN expression in U87MG cells. Overall, our data add higher inositol phosphates to the list of important cellular regulators [Y. Huang, R.P. Wernyj, D.D. Norton, P. Precht, M.C. Seminario, R.L. Wange, Oncogene, 24 (2005) 3819 ] the levels of which are modulated by expression of the highly pleiotropic PTEN protein.

Electron impact excitation of Gd XXXVII and radiative rates for Ni-like ions with 60

Energy levels and radiative rates for transitions among the 107 finestructure levels belonging to the (1s(2)2s(2)2p(6)) 3s(2)3p(6)3d(10), 3s(2)3p(6)3d(9)4l, 3s(2)3p(5)3d(10)4l, and 3s3p(6)3d(10)4l configurations of Ni-like ions with 60 less than or equal to Z less than or equal to 90 have been calculated using the GRASP code. The collision strengths (Omega) have also been computed for transitions in Gd XXXVII at energies below 800 Ryd, using the DARC code. Resonances have been resolved in a fine energy mesh in the threshold region, and excitation rate coefficients have been calculated for transitions from the ground level to excited levels at temperatures below 2500 eV. These have been compared with those available in the literature, and enhancement in the values of rates, due to resonances, has been observed up to an order of magnitude for some of the transitions.

Lack of Association Between the Trp719Arg Polymorphism in Kinesin-Like Protein-6 and Coronary Artery Disease in 19 Case-Control Studies

Objectives: We sought to replicate the association between the kinesin-like protein 6 (KIF6) Trp719Arg polymorphism (rs20455), and clinical coronary artery disease (CAD).
Background: Recent prospective studies suggest that carriers of the 719Arg allele in KIF6 are at increased risk of clinical CAD compared with noncarriers.
Methods: The KIF6 Trp719Arg polymorphism (rs20455) was genotyped in 19 case-control studies of nonfatal CAD either as part of a genome-wide association study or in a formal attempt to replicate the initial positive reports.
Results: A total of 17,000 cases and 39,369 controls of European descent as well as a modest number of South Asians, African Americans, Hispanics, East Asians, and admixed cases and controls were successfully genotyped. None of the 19 studies demonstrated an increased risk of CAD in carriers of the 719Arg allele compared with noncarriers. Regression analyses and fixed-effects meta-analyses ruled out with high degree of confidence an increase of <2% in the risk of CAD among European 719Arg carriers. We also observed no increase in the risk of CAD among 719Arg carriers in the subset of Europeans with early-onset disease (younger than 50 years of age for men and younger than 60 years of age for women) compared with similarly aged controls as well as all non-European subgroups.
Conclusions: The KIF6 Trp719Arg polymorphism was not associated with the risk of clinical CAD in this large replication study.