Iodine biofortification of vegetable plants-An innovative method for iodine supplementation

To elevate the iodine level in edible plants has been shown to be an excellent approach to correct iodine deficiency.We have proposed an innovative approach to produce iodine supplementation by growing vegetables on soils with algal-based iodized organic fertilizer.Ten species of vegetables were tested.The biological absorption and migration of the iodine within the vegetable plants were revealed using microscopy with silver iodide precipitation technique.The results show that the absorption of iodine by the vegetable increases with increasing amount of the algal-based iodized organic fertilizer in general.And the uptake of iodine by leaf vegetable is significantly greater than that by fruit vegetable.Distribution of iodine in various plant organs shows a trend of decreasing iodine concentration from root,leaf,stalk,to fruit.A similar of decreasing concentration can also be found in various cells(cytoplasm>cytoderm>organelles).The exploration of the iodine uptake and biogeochemistry migration mechanisms provides an important scientific foundation for establishing a new method of producing a natural iodine supplementation by iodine biofortification of vegetables.     

La/ZSM-5分子筛上1-己烯活化的理论研究

基于 54T 团簇模型,采用 ONIOM 分层计算方法,研究了1-己烯分子与镧改性ZSM-5分子筛的相互作用,并详细描述了1-己烯分子在镧改性ZSM-5分子筛上的催化活化反应机理。计算结果表明,1-己烯与镧改性ZSM-5分子筛之间没有发生π配位吸附,只存在更加微弱的物理吸附,从而导致了镧改性ZSM-5分子筛烯烃吸附能力的降低。镧物种酸性中心的O—H键在活化能作用下通过极性分解直接发生质子迁移使1-己烯被质子化,经过碳正离子过渡态,形成稳定的烷氧基活化产物,从而使1-己烯被活化。计算得到的1-己烯的活化能垒是160.64 kJ/mol,这为文献中报道的镧改性ZSM-5分子筛的烯烃吸附能力和催化活性降低提供理论支持,有助于探究镧改性前后ZSM-5分子筛催化性能改变的原因。     

Coastal seafloor observatory at Xiaoqushan in the East China Sea

The seafloor observation system is becoming an important infrastructure for marine research because it is transforming oceanic research from temporal investigation to long term observation.The East China Sea coastal seafloor observatory,located between 30°31′44″N,122°15′12″E and 30°31′34″N,122°14′40″E,is constructed near the Xiaoqushan Island outside the Hangzhou Bay on the inner continental shelf of the East China Sea.The observatory is connected by a submarine optical fiber composite power cable that is more than one kilometer long and consists of a special junction box that transmits power and communication signals to different instruments.The special junction box has a variety of waterproof plugs and connects to three different instruments installed in a trawl preventer.The submarine optical fiber composite power cable is landed on the platform by The East China Sea Branch,State Oceanic Administration and the power is continuously supplied by the solar panels and solar battery on the top of the platform.The real time data are directly sent through the cable to the platform and are transmitted by CDMA wireless to the receiver at the State Key Laboratory of Marine Geology of Tongji University.Measurements at the observatory have been taken since April 20,2009 after installation and the results have been interpreted.The characteristics of the near bottom boundary are constrained by a sediment suspension model using portion of the observed data.In particular,discussion is provided on the sea surface height anomaly at Xiaoqushan Island influenced by the tsunami driven by the 2010 Earthquake in Chile.The successful establishment of the coastal seafloor observatory is the first step toward future development of seafloor observation systems in China.It not only accumulates experiences in technology and engineering,but also paves the way for performing important oceanic research using the long term continuous observation platform.     

C-terminal domain of Chk1 regulates its subcellular location and kinase activity for DNA repair

Effector kinase Chk1 is an evolutionarily conserved protein kinase. It is a key mediator linking the mechanisms that monitor DNA integrity to components of the cell cycle engine. In this study, recombinant vectors pEGFP-C1-Chk1/C 288/C 334/C 368 were constructed and transfected into HeLa cells to study the effect of the Chk1 regulatory domain on the regulation of subcellular Chk1 location in response to DNA damage. We found that DNA damage-induced nuclear accumulation is regulated by 34 amino acids (334–368) in the C-terminal regulatory domain. Recombinant vectors pXJ41-Chk1/C 288/C 334/C 368 were co-transfected with reporter plasmid pEGFP-N2 into HeLa cells to study the repair abilities of the different human Chk1 truncation mutants. In addition, recombinant vectors were transfected into HeLa cells to study the effects of the different truncation mutants on the cell cycle. Furthermore, to study the kinase activity of the different truncation mutants, Ser216 phosphorylation of Cdc25C was studied by Western blot analysis. We found that the enzymatic activity of C 368, missing the 108 C-terminal amino acids (368–476), was higher than that of full-length Chk1, and C 368 delayed the cell cycle progression. The enzymatic activity of C 334, missing the 142 C-terminal amino acids (334–476), was equivalent to that of full-length Chk1. C 288, missing the 188 C-terminal amino acids (288–476), had almost no enzymatic activity, suggesting that the regulatory domain contains both inhibitory and regulatory elements. This study provides useful information for further research on Chk1 function.     

机载激光雷达扫描揭示海原断裂带微地貌的精细结构

第四纪地貌体的位错精确测量是活动断裂研究的基础, 提高地形数据的分辨率是关键. 激光雷达三维扫描(LiDAR)是一种快速获取高精度地形数据的先进有效方法. 在我国一条标志性的大型活动断裂——海原断裂带上成功开展了机载激光雷达扫描, 覆盖128 km的区段, 获取了高密度的激光点云数据和达0.5 m分辨率的数字高程模型(DEM), 实现了对海原断裂带的微地貌形态和断层几何的高清晰度三维再现. 高密度大范围的三维激光扫描促进断裂活动性和古地震复发规律的精细化研究.     

Records of the tsunami induced by the 2010 Chilean earthquake from Xiaoqushan seafloor observatory in the East China Sea

Sea-level variation can be induced by periodic tides, stochastic wind, air pressure, and swell. Larger sea-level variation has the potential to cause coastal disasters. In this paper, real-time continuous data obtained by the Xiaoqushan seafloor observatory in the East China Sea were analyzed employing frequency power spectral and tidal harmonic methods to extract the major components and periodicities of sea-level change. The sea-level anomaly (sla) was calculated by subtracting the tidal components from the observed sea level data. In the study period, the correlation between sla and the local north-south wind speed was high with a correlation coefficient of 0.65 at the 95% confidence level. The local wind-induced sea-level anomaly (sla wind ) was therefore computed through linear fitting. Although sla wind is one of the main components of sla, the residual sea-level anomaly (sla residual ) obtained by subtracting sla wind from sla is not zero, suggesting that there are other factors besides wind. Detailed analysis of the sea-level data at the time of the 8.8-magnitude Chilean earthquake on February 27, 2010 showed a peak sla residual value of 0.48 m at around 15:00 on February 28, which was highly coincident with the tsunami arrival time forecast by the Pacific Tsunami Warning Center. The peak sla residual event is therefore linked with the tsunami induced by the 2010 Chilean earthquake. This is the first time that a tsunami has been detected using real-time continuous data recorded by a seafloor observatory in the sea off China. Such observations are expected to improve tsunami forecast models and promote the development of a tsunami warning system and a seafloor observatory network in the East China Sea.     

弱风化泥岩崩解特性试验研究

三峡库区广泛分布的泥岩遇水易软化、崩解,致使许多库岸工程在水文涨落下出现病害。为了分析泥岩崩解特性及崩解机理,通过室内崩解试验,结合细观裂隙扩展规律及矿物成分的涉水特性,对泥岩崩解现象进行详细描述,阐释了泥岩崩解的机理。认为泥岩的崩解是裂隙扩展的过程,是与泥岩的沉积形成相反的过程;崩解可分为三个阶段:毛细裂隙吸水阶段、裂隙贯通阶段、二次崩解阶段;崩解物的颗粒粒径分布与泥岩颗粒中的矿物成分关系密切。     

多组元铝热剂的反应特性

采用热分析法对多组元铝热剂Ｆｅ２ｏ３－ＣｒＯ３－ＮｉＯ－Ａｌ的反应行为进行了研究，结果发现，ＣｒＯ２的分解、气化、挥发等热特性强烈影响铝热剂反应行为和反应产物的成分。     

活化扩散和支撑层阻力对沸石膜分离性能的影响

采用Maxwell Stefan(MS)方程描述分离膜组件中沸石膜及支撑层区域内的晶内扩散、活化扩散、分子扩散和努森扩散,建立了一维定态扩散模型以模型化预测甲烷、乙烷在MFI沸石膜组件中单、双组分的渗透特性。结果表明：支撑层阻力对单组分以及混合物在膜组件中的渗透通量有显著影响,阻力大小与支撑层结构（孔径和空隙率等）相关;支撑层阻力中努森扩散阻力的效应对分子量大的组分以及在较低分离温度下不能忽略;考虑支撑层阻力时,甲烷、乙烷在膜层中气相活化扩散的活化能分别为(8.1±0.2)和(9.2±0.1)kJ/mol,约为文献报道值的1/2;温度越高膜层中气相活化扩散越明显,其对组分总通量的贡献甚至要大于表面扩散。