Effects of isorhapontigenin on cell cycle arrest and down-regulation of cyclin D1 expression in bladder cancer cells

AIM：To explore the inhibitory mechanism of isorhapontigenin (ISO) on the proliferation, migration and invasion of UMUC3 bladder cancer cells. METHODS：Human UMUC3 bladder cancer cells were pretreated with ISO, and the proliferation of the cells was observed under phase-contrast microscope and by ATPase assay. The expression of cyclin D1 was determined by RT-PCR and Western blotting. The cell cycle alteration was detected by flow cytometry, and the cell migration was examined by wound-healing assay. RESULTS：Over 20 μmol/L of ISO significantly inhibited the proliferation of UMUC3 cells with the IC50 of (22.5±2.8) μmol/L. The mRNA and protein levels of cyclin D1 in UMUC3 cells were markedly decreased after treatment with ISO. Exposure of UMUC3 cells to low dose (5 μmol/L) of ISO led to significant induction of G0/G1 growth arrest at both 12 h (58.82%) and 24 h (63.94%), compared with the negative control cells (47.33%) without inducing obvious apoptosis. ISO at dose of 5 μmol/L also markedly inhibited the cell migration. CONCLUSION：ISO significantly exhibits inhibitory effects on the proliferation and migration of human bladder cancer cells by down-regulation of cyclin D1 expression accompanying with G0/G1 cell cycle arrest.     

Effects of nitrogen and water stress on the rehydration,endogenous hormonal regulation and yield of maize

Water scarcity is known to be a strong limiting factor affecting maize grown and yield in cold semi-arid regions. Numerous studies have shown that rehydration improves maize growth. Our study aimed to explore the effects of rehydration treatments on maize growth and yield under water and nitrogen stress during different growth stages. We selected the drought-tolerant maize variety Nendan 19 (ND19) and subjected it to water stress during the V6 (sixth-leaf), R2 (filling) and R6 (maturity) growth stages and a rehydration treatment after each stress stage. Our results indicated that N1 (N100 kg N ha⁻¹) and N3 (N300 kg N ha⁻¹) treatments significantly increased the leaf moisture status relative to water content (RWC), bound water content (BWC), free water content (FWC) and water potential (WP)) at different growth stages. Similar trends were observed in the accumulation of plant leaf and root hormones (zeatin+zeatin riboside, indole-3-acetic acid, abscisic acid and gibberellic acid), photosynthetic pigments and chlorophyll fluorescence. However, under the same water stress conditions, they decreased as the N rate increased and reached a minimum value in the S3 (water stress for N3) treatments. In addition, with growth stage advancement and extension of the rehydration time, both showed a gradual upward trend. The results showed that to save water resources in the cold semi-arid region, rehydration treatments (R2S1 and R2S3) significantly increased the photosynthetic pigments and chlorophyll fluorescence parameters, leaf moisture status, biomass, 100-grain weight, hormone content, ear characteristics and grain yield of maize.     

从油橄榄引种看我国木本食用油料产业的发展

为了科学制定木本油料产业发展规划,论述了我国发展木本食用油料产业的优势和特点,分析了橄榄油的营养价值和市场动力,简述了我国油橄榄引种栽培的历史,指出了我国目前木本食用油料产业发展中存在的主要问题,并提出了促进木本食用油料产业发展的对策与措施。     

细胞色素C氧化酶的纯化及动力学性质研究

采用硫酸铵分级沉淀和CytochromeC -Sepharose 4B亲和层析 ,从牛心线粒体中纯化了细胞色素C氧化酶 (CytochromeCOxidase ,简称CCO ) ,其比活性为 1 7 88s- 1 ·mg- 1 ,聚丙烯酰胺凝胶电泳为一条带 ,血红素A (HemeaA)含量达到 1 5 4nmol/mg。纯化后的CCO具有典型的CCO特征 ,还原态CCO峰值出现在 60 5nm和 443nm ,氧化态CCO峰值出现在 598nm和 42 4nm。CCO的稳态动力学参数Vm1、Km1、Vm2 、Km2 分别为 1 42s- 1 、 0 53μmol/L、 2 71s- 1 、 1 81 μmol/L。     

松茸菌株对6种松树幼苗的感染及其菌根解剖学研究

利用我国滇产松茸9924菌株及日产松茸99606菌株，分别对云南松、华山松、马尾松、火炬松、湿地松及加勒比松6种松树幼苗实施人工菌根接种。研究结果表明，接种后90d的云南松和湿地松分别有75％和78．1％的幼苗受感染并形成菌根；接种后180d,6种松树幼苗分部都可形成菌根，菌根感染率分别达90．63％－100％，感染指数达50．00－84．68；菌根形态主要有棒状、二叉分枝状及多叉分枝状3种；随树种的不同，各类菌根形态所占比例也不同；不同树种根系上形成菌根的长度也有差异，以马尾松根系上的菌根最长，华山松的菌根最短；此外，各种组合之间在菌套厚度，哈蒂氏网结构上也略有差别。     

内蒙农牧交错带地区土地利用方式和施肥对土壤碳库的影响

内蒙武川是我国典型的内蒙农牧交错带地区,土地利用方式转变和施肥是影响该地区农业生产和土壤碳储量的重要人类活动。选取内蒙武川地区,针对不同土地利用方式(耕地、退耕还林/还草)和施肥措施(化肥、有机肥)的长期定位试验土壤,分析土壤有机碳(SOC)、土壤无机碳(SIC)和全氮(TN)含量和储量,结合13C和15N稳定同位素方法,研究土地利用方式和施肥措施对于该地区土壤碳氮转化的影响规律。研究表明,退耕还灌/还草后,SOC储量较耕地均有显著提高(提高幅度0.60~0.98 Mg hm-2 a-1),SIC储量也增加或保持相同水平(柠条地除外)。相比不施肥处理,施用有机肥能显著增加SOC(1.08~1.19 Mg hm-2 a-1),施化肥处理则会降低SIC(0.06~0.16 Mg hm-2 a-1),且主要影响次生碳酸盐。施肥SIC中原生碳酸盐比例(0~23%)低于自然土壤(3%~29%)。施肥措施对于土壤碳氮的转化强度远大于土地利用方式的改变。对于内蒙等干旱半干旱地区土壤,土地利用和施肥措施对于土壤有机和无机碳的影响应该在区域固碳管理中给予全面考虑。     

有机肥对石灰性土壤中锌,锰生物有效性的影响

本研究发现，有机肥猪粪，牛粪和腐熟玉米秸秆具有一定的提供锌、锰能力；石灰性土壤施有机肥能显著提高土壤锌锰的有效性；有机肥对土壤中锌、锰具有一定的活力能力；锌肥与有机肥配施可降低土壤对锌肥的固定能力，提高锌肥的利用率。     

兴安落叶松天然林树冠生长特性分析

分析兴安落叶松天然林分级木和林分冠生长特性,建立冠幅生长及单株冠、枝、叶生物量模型。结果表明:1)年龄36～39年、密度983～3263株·hm-2林分和年龄54～61年、密度1101～2241株·hm-2林分,随林分密度增加,分级木冠幅差距趋于减小;冠长占树高比例及冠长与冠幅比值增加;优势木、平均木和被压木平均冠积分别达22.479,15.296,6.179和26.864,11.154,8.192m3。2)年龄36～39年和54～61年林分优势木、平均木和被压木平均单株冠生物量分别为0.0082,0.0049,0.0009和0.0079,0.0038,0.0014t;占单株地上生物量平均比例分别达18.5%,24.2%,17.3%和15.9%,12.0%,20.5%。3)单株冠生物量分配中,枝比例高于叶比例,并因分级木不同而不同。年龄36～39年和54～61年林分,优势木、平均木、被压木枝生物量比例分别为76.6%,74.7%,66.6%和76.8%,73.3%,71.4%;叶生物量比例分别为23.4%,25.3%,33.4%和23.2%,26.7%,28.6%。4)年龄36～39年和54～61年林分,林分...