Nanosized calcium phosphate powder had been synthesized via an inverse microemulsion processing route, which used cyclohexane as the oil phases, octaethylene glycol monododecyl ether (C12EO8) as surfactant phase, and an aqueous Ca(NO3)2 and (NH4)2HPO4 solution as the water phase. A wide variety of morphologies were encountered in synthesis which produced nanosphere (25-40nm in diameter), sheet-like (3-16nm in width and 50-300nm in length), rod-like (10-17nm in diameter and 24-50nm in length) and needle-like (4-8nm in diameter and 80-100nm in length). The great structural diversity was resulted from the different value of the molar ratio of water to surfactant, W0. Particles were visualized by transmission electron microscopy (TEM) and the identities of powder confirmed by FT-IR and X-ray diffraction (XRD).

In order to identify genes induced during the water stress response in maize (Zea mays) seedlings, suppression subtractive hybridization (SSH) was performed using mixed cDNAs prepared from maize seedlings treated with 20% PEG as testers and cDNAs from unstressed maize seedlings as drivers. A forward subtractive cDNA library was constructed, from which 960 recombinant colonies were picked and amplified. Through differential screening of the subtractive cDNA library, 533 clones were identified as water stress induced. After sequencing, 190 unique expressed sequence tags (ESTs) were obtained by clustering and blast analysis, which included transcripts that had previously been reported as responsive to stress as well as some functionally unknown transcripts. The ESTs with significant protein homology were sorted into 13 functional categories. A cDNA marcoarray containing the 190 unique ESTs was used to analyze their expression profiles in maize seedling during both PEG treatment and natural drought. The results indicated that 67 ESTs in leaves and 113 ESTs in roots were significantly up-regulated by PEGstress. 123 ESTs were found to be up-regulated for at least one time-course point in either maize leaves or roots. Correspondingly, 163 ESTs were significantly up-regulated by drought sress. Results from the hierarchical cluster analysis suggest that the leaves and roots of maize seedlings had different expression profiles after PEG treatment and that there was a lot of overlap between PEG-and drought-stress induced up-regulated transcripts. A set of transcripts has been identified, which have significantly increased expression and probably involved in water stress signaling pathway based on data analysis.

以Ti（SO4）2水溶液为前驱体，NH3·H2O为沉淀剂，以十二烷基苯磺酸钠（dodecyl benzene sulfonate, DBS）为表面活性剂，采用常温水解沉淀法制备出了纳米TiO2粉体。用XRD测试粉体的晶相组成；用TEM分析粉末的晶体形貌。研究了溶液的pH、表面活性剂、煅烧温度等对纳米TiO2颗粒尺寸的影响。结果表明：当溶液pH为2.0～4.0，分散剂质量分数为1.5%时，水解沉淀得到的TiO2晶粒尺寸在1O～20nm之间。研究烧结过程中晶粒的变化时发现：由于DBS的包覆，有效地抑制了煅烧过程中晶粒的长大。

Brassinosteroids (BRs) are natural plant growth regulators required for plant growth and development. Physiological studies have demonstrated that exogenous BRs induced the elongation of coleoptiles and mesocotyls in maize. However, little is known about the function of endogenous BRs in maize or other grass species. The Arabidopsis DWF1/DIM is a bifunctional protein which catalyses both the △24 isomeration, and subsequently, the △24(25) reduction in BRs biosynthesis pathway. To better understand the role of DWF1 of monocot plants in BRs biosynthesis, we cloned a maize gene, ZmDWF1, which has extensive sequence similarity to Arabidopsis DWF1. ZmDWF1 is predicted to encode a 562-amino-acid protein that has 95 and 86% similarity with rice OsDWF1 and Arabidopsis DWF1, respectively. Southern blot result showed that one copy of ZmDWF1 is present in maize genome. Northern blot analyses revealed that expression of ZmDWF1 is temporally and spatially regulated during development. Transgenic maize plants with double-stranded ZmDWF1 RNA were generated. Some of them have dwarfed phenotype varying in severity. Western blot results also demonstrated the expected cosuppression of ZmDWF1 gene in transgenic plants.