光催化剂的应用及前景

光催化剂就是在光子的激发下能够起到催化作用的化学物质的统称。它作为一种绿色催化剂,近年来取得了巨大进展。推动光催化反应研究的巨大动力来源于清洁生产﹑能源危机﹑环境保护的强烈要求,以及光催化剂本身潜在的探索价值和应用潜力。     

溶栓治疗急性脑梗塞的现状与进展

及时有效地治疗急性脑梗塞（ACI）是现代医学急需解决的一个问题，近年来，在这方面取得了许多进展，针对脑梗死周围缺血性半暗区的治疗已成为研究热点，本文就目前研究较多的超早期溶栓治疗和脑细胞保护剂的应用两方面作一综述。     

光化学法脑缺血后细胞凋亡及其相关基因bcl-2表达的变化

采用ＴＵＮＥＬ染色及免疫组织化学技术对光化学法脑缺血后细胞凋亡及其相关基因ｂｃｌ－２表达的变化进行了研究。结果发现，缺血后１２ｈ，损伤侧皮层缺血区内凋亡细胞数及ｂｃｌ－２免疫反应阳性细胞数明显增加，一直持续至缺血后７２ｈ；并呈现下列时程变化：在缺血后３ｈ每张切片上几乎无凋亡细胞出现，以后逐渐增加，缺血后１２ｈ达到峰值，缺血后２４ｈ和缺血后７２ｈ逐渐减少，但仍高于假手术组水平。凋亡相关基因ｂｃｌ－２的表达在缺血后３ｈ以前不明显，缺血后１２ｈ逐渐增加，缺血后２４ｈ最多，以后逐渐下降。上述结果提示，缺血后凋亡细胞的时程变化可能与缺血后梗塞灶的发生和发展有关，而ｂｃｌ－２表达的变化可能与抑制细胞凋亡、发挥内源性细胞保护作用有关。     

灰色GM（1,1）模型的性质及其应用

灰色ＧＭ（１，１）模对生态预测有重要应用，本文讨论了它的一个改进模ＧＭ（１，１），并深化了文（１）提出的两个问题，给出了较简明的证法，还确定了文（１）所希望的一个“合适的”常数。     

Immunological Properties of Recombinant Mycobacterium bovis Bacillus Calmette-Guérin Strain Expressing Fusion Protein IL-2-ESAT-6

The live vaccine Mycobacterium bovis bacillus Calmette-Guérin (BCG) provides variableefficacy against adult pulmonary tuberculosis (TB).Recombinant BCG,expressing either immunodominantantigens or Th1 cytokines,is a promising strategy for developing a new TB vaccine.However,not much isknown about whether the introduction of cytokine and specific antigen genes concurrently into the BCGstrain could improve the immunogenicity of BCG.In this study,a recombinant BCG strain (rBCG) expressingthe fusion protein human interleukin (IL)-2 and ESAT-6 (early secreted antigenic target-6 kDa) antigen ofMycobacterium tuberculosis was constructed.Six weeks after BALB/c mice (H-2~d) were immunizedwith 10~6 colony forming units (CFUs) BCG or rBCG,splenocyte proliferation was determined with MTT[3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide] assay,IL-4 and interferon (IFN)-γproducedby splenocytes were tested by enzyme linked immunosorbent assay (ELISA,) and the cytotoxicity ofsplenocytes from immunized mice to P815 cells (H-2~d) expressing ESAT-6 protein was measured usingCytoTox 96 Non-Radioactive Cytotoxicity Assay.Compared with native BCG-vaccinated mice,rBCG inducedstronger Th1 responses that were confirmed by high lymphoproliferative responses and IFN-γproductionto culture filtrate protein (CFP) or ESAT-6 protein.Moreover,rBCG induced significant enhanced CTLresponses against P815-ESAT-6 cells.Results from rBCG-immunized mice demonstrated that introducingthe il-2 and esat-6 genes into BCG could enhance Th1 type immune responses to ESAT-6.Further investigationis needed by introducing other Th1 cytokines and antigens into BCG to optimize the protective efficacyagainst TB.