Cmponent Study on Flavonoids From Leaves of Dendrocalamus Latiflorus

从麻竹（Dendrocalamus latiflorus）叶中分离得到四个黄酮类化合物。经性质和光谱（UV,IR,MS,1HNMR,13CNMR等）法鉴定其结构,分别为牡荆苷（?）,芦丁（II）,山奈酚-3-O-β-D-芸香糖苷（III）,山奈酚-3-O-β-D-葡萄糖基(1-2)-α-L-鼠李糖苷（IV）。四种化合物均为首次从该植物中得到。     

Three new water-soluble alkaloids from the leaves of Suregada glomerulata (Blume) Baill

Three new water-soluble alkaloids (1-3) together with twelve known compounds (4-15) have been isolated from the water extract of leaves of Suregada glomerulata. Their structures were determined by spectroscopic analysis and chemical method. Compounds 1-3 were evaluated for their in vitro inhibitory activity against α-glucosidase and HIV-1 replication. However, no significant activities were found.     

奶牛酪蛋白αs1基因片段的扩增及泌乳素对其基因表达的影响

从泌乳中国黑白花奶牛的乳腺组织中提取基因组RNA，根据报道的奶牛酪蛋白αs1 mRNA序列设计其上、下游引物，用RT-PCR进行cDNA扩增，获得1条434bp的片段。测序分析结果表明，该片段为奶牛酪蛋白αs1 cDNA的部分序列，编码130个氨基酸组成的多肽；除一个碱基发生变异外，其余部分与报道的乳腺酪蛋白αs1cDNA序列完全一致。以此为基础，并以GAPDH为内标，研究了不同浓度泌乳素对旋转培养下奶牛乳腺组织酪蛋白αs1基因表达的影响。结果表明，奶牛乳腺组织在培养24h后，泌乳素为10μg／mL组的酪蛋白αs1基因表达水平最高，且显著高于对照组和2．5μg/mL组（P〈0．01），而与5．0和7．5μg／mL组之间差异不显著（P〉0．05）；对照组与2．5、5．0和7．5μg／mL组之间，2．5μg／mL组与5．0、7．5和10．0μg／mL之间差异均极显著（P〈0．01），而5．0μg／mL以上的3组之间差异不显著（P〉0．05）。结果提示，泌乳素的添加浓度以5．0μg／mL为佳。     

Enhancing the Simplified Surface Energy Balance (SSEB) approach for estimating landscape ET: Validation with the METRIC model

Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r² improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r² from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.     

野生二粒小麦α-淀粉酶抑制因子编码基因序列分析

对3份野生二粒小麦(Triticum dicoccoides)材料的抗虫24 kDaα-淀粉酶抑制因子编码基因进行分离克隆,得到72个24 kDaα-淀粉酶抑制因子基因,并进行序列分析。结果发现,α-淀粉酶抑制因子在野生二粒小麦中以多拷贝形式存在,经卡方检验初步推断野生二粒小麦中的α-淀粉酶抑制因子成熟蛋白编码基因序列变异类型在供试材料间无显著差异。序列分析表明,24 kDaα-淀粉酶抑制因子成熟蛋白编码基因序列无论在野生二粒小麦种内还是与小麦属的其他物种之间,都具有很高的一致性,说明该基因在进化过程中十分保守。     

甘肃滩羊血清酯酶和α-淀粉酶多态性分析

运用聚丙烯酰胺凝胶电泳技术(PAGE)对甘肃滩羊产区皋兰、景泰及靖远3293只滩羊的血清酯酶(Es)、α-淀粉酶(α-Amy)基因座多态性进行了检测分析。结果表明:甘肃滩羊Es基因座存在3种基因型Es++ 、 Es+- 、 Es-- ,它们由Es+、Es-两个共显性等位基因控制,其中Es+-基因型在3个群体中均占优势,频率分别为0.620 0(皋兰)、0.666 6(景泰)、0.730 0(靖远);在皋兰群体和景泰群体中,Es-基因占优势,基因频率分别为0.540 0和0.548 4,而在靖远群体中优势基因则为Es+,其基因频率为0.525 0。在α-Amy基因座上没有检测到多态性。     

松节油微波加热水合反应制松油醇

以HAc为催化剂,在微波加热条件下,对松节油直接水合制松节醇进行研究.结果表明:微波加热较传统加热更能促进反应的进行;在优化反应条件下,直接将松节油于85℃水合反应5h,其转化率达85.91%,选择性为0.453.     

银耳α–微管蛋白基因的克隆及序列分析

 根据GenBank上已发表的其他真菌α–微管蛋白基因序列中的保守区域设计简并引物,扩增出银耳α–微管蛋白基因的cDNA部分序列。分别利用SEFA-PCR方法和RACE技术,克隆了银耳α–微管蛋白基因的DNA和cDNA全长序列。银耳α–微管蛋白基因DNA全长1 962 bp,含有9个内含子,cDNA全长1 347 bp,编码448个氨基酸。生物信息学分析结果表明：银耳α–微管蛋白基因的cDNA序列与新型隐球酵母有80%相似性,编码的蛋白质属于Tubulin_FtsZ超家族中的α–微管蛋白亚家族,氨基酸序列中存在保守的GTP结合区域GGGTGSG,系统发育树显示银耳与新型隐球酵母距离最近。     

在羊驼皮肤黑色素细胞中α-黑素细胞刺激素对诱导一氧化氮合酶的影响

为研究α-黑素细胞刺激素（α-Melanocytestimulatinghormone,α-MSH）对诱导型一氧化氮合酶（NOS2）在羊驼皮肤黑素细胞中的影响。采用体外培养正常羊驼皮肤黑素细胞,检测不同浓度α-MSH（0、10-9、10^-8、10^-7moL／L）对羊驼皮肤黑素细胞中诱导型一氧化氮合酶（NOS2）基因...     

植物乳杆菌α-半乳糖苷酶基因（melA）的克隆与序列分析

试验以L.plantarum1.557的基因组DNA为模板,通过PCR技术扩增α-半乳糖苷酶基因（melA）基因,PCR产物经纯化回收后克隆至pMD18-T载体中,转化E.coli DH5α感受态细胞,筛选阳性克隆,提取质粒进行SacⅠ和Sph Ⅰ酶切及PCR扩增鉴定,并对melA基因片段进行序列测定。结果表明,测得的melA基因序列全长2240 bp,含有酶切位点、启动子、SD序列及编码738个氨基酸的开放阅读框,理论分子质量为84 ku;4种核苷酸中GC含量为47.45%、AT含量为52.55%;序列中有3个碱基发生了变化,均为无义突变,未导致其推导的氨基酸的改变;序列测定结果与GenBank中登录的序列进行比较,核苷酸和氨基酸序列的同源性除与AY873840相比分别为96.6%和92.2%外,其余均大于99%。试验成功克隆了melA基因,为进一步构建重组表达载体奠定了基础。