城市土地利用与经济协调发展度评价研究——以天水市为例

针对天水经济快速发展、用地需求增速明显而土地供给约束日益加大的问题,从土地资源利用的规模、结构、效率及经济发展水平方面出发,构建了反应土地利用与经济协调发展程度的综合指标体系,该体系由目标层、准则层、因素层和指标层4个层次及28个具体指标构成。基于均方差决策求解法,对天水市的土地利用与经济协调发展度进行综合评价。结果表明:1996~2008年土地利用与经济发展两系统协调程度不高、质量欠佳,协调度指数总体趋势下降;土地利用与经济发展系统演进模式由经济发展滞后土地利用模式转变为土地利用滞后经济发展模式。     

叶用辣木新品种‘中林2号’

 ‘中林2号’是从缅甸引种的辣木中选育出的新品种。腋芽、附芽和潜伏芽排列密集,成枝率高。截干后的植株再生能力强。复叶长33.5 cm,宽21.7 cm。盛产期年均鲜叶产量可达30 000 kg · hm^-2。叶粉蛋白质含量可达293 g · kg^-1。适于营建叶用良种园。     

SIRT1 promotes autophagy of pancreatic cancer cells induced by hypoxia via regulating FOXO1/RAB7 signaling pathway

AIM: To investigate the effect of SIRT1 on the autophagy of pancreatic cancer cells under hypoxia condition, and to analyze the underlying mechanism of regulating FOXO1/RAB7 signaling pathway. METHODS: Western blot and immunofluorescence methods were used to determine the expression of SIRT1 in the pancreatic cancer cells. The small interfering RNA targeting SIRT1 and SIRT1 over-expression plasmid were transfected into the pancreatic cancer Panc-1 cells. Confocal microscopy was used to detect the LC3 expression. Western blot was used to analyze the protein levels of LC3, p62 and FOXO1/RAB7 signaling pathway-related molecules. Co-immunoprecipitation was used to detected the protein interaction between SIRT1 and FOXO1. RESULTS: The expression level of SIRT1 in the nucleus of Panc-1 cells was increased under hypoxia condition. Compared with negative control under hypoxia condition, knock-down of SIRT1 expression attenuated the autophagy flux in the pancreatic cancer Panc-1 cells (P<0.05). Over-expression of SIRT1 increased the protein levels of FOXO1 and RAB7. On the contrary, knock-down of SIRT1 expression inhibited the protein levels of FOXO1 and RAB7. The protein interaction between SIRT1 and FOXO1 in the pancreatic cancer cells was observed. CONCLUSION: SIRT1 in pancreatic cancer Panc-1 cells under hypoxia condition is over-expressed in the nucleus. Down-regulation of SIRT1 inhibits autophagy and its mechanism may be related to FOXO1/RAB7 signaling pathway.     

Effects of baicalin on CA46 cell xenografts in nude mice

AIM: To study the effects of baicalin on CA46 cell xenografts in nude mice. METHODS: The nude mice with CA46 cell xenografts were treated with drugs via intraperitoneal injection daily, and were divided into 5 groups: negative control group, 15 mg/kg baicalin group, 30 mg/kg baicalin group, 60 mg/kg baicalin group and 4 mg/kg etoposide (VP-16) positive control group. After 12-day treatment, the weight of CA46 cell xenografts stripped from some nude mice in the 5 groups was used to evaluate the effect of baicalin on xenograft growth in the nude mice. The apoptosis, necrosis and pathological changes of the xenograft cells were examined under light microscope and transmission electronic microscope respectively. The expression levels of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway-related proteins extracted from xenografts were determined by Western blotting. The other nude mice with CA46 cell xenografts in the 5 groups continued to be treated with the drugs until death in order to evaluate the effect of balcalin on survival time of the nude mice with CA46 cell xenografts. RESULTS: Baicalin remarkably inhibited the growth of CA46 cell xenografts, induced apoptosis and necrosis of xenograft cells, and reduced the protein expression of phospho-Akt (p-Akt), nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR) and phospho-mTOR (p-mTOR) in the xenografts after 12-day treatment. Furthermore, baicalin prolonged the survival time of the nude mice with CA46 cell xenografts in a dose-dependent manner. CONCLUSION: Baicalin inhibits the growth and induces apoptosis of CA46 cell xenografts in the nude mice, and prolongs the survival time of the nude mice with CA46 cell xenografts through the mechanism of down-regulating PI3K/Akt/NF-κB and PI3K/Akt/ mTOR signaling pathways.     

丹参药渣栽培糙皮侧耳和毛头鬼伞

采用不同比例丹参(Salviae miltiorrhiza)药渣替代玉米芯对糙皮侧耳(Pleurotus ostreatus)、毛头鬼伞(Coprinus comatus)供试菌株进行栽培实验.经栽培收获两茬子实体,分别对不同配方两个菌种的菌丝长速、单位料重产量、生物学效率等指标进行统计分析.结果表明:在单位料重产量及生物学效率表现上,随培养料中所含丹参药渣比例增加而增加;在菌丝长速表现上则相反.经丹参药渣、玉米芯的碳氮比分析(28.5∶1;88.1∶1)得知,栽培料中随药渣含量的增加氮素含量相应提高(碳氮比55.27∶1～27.44∶1,氮含量为0.76％～2.43％),成为两个菌种产量增加的主要原因.     

基于表型和SRAP 标记的切花菊品种遗传多样性分析

 利用45 个表型性状和SRAP 标记分析56 个切花菊品种的遗传多样性。表型变异分析结果 表明：21 个性状表现出品种内一致性高及品种间特异性强;主成分分析发现,主成分贡献值较大的性状 有花序直径、花序类型和瓣型等花部性状,其次是叶部和茎杆性状,说明所选用的切花菊品种在分类时 应以花部性状为主,叶部和茎杆性状为辅;表型性状基于遗传距离UPGMA 聚类,将56 个切花菊品种分 为平瓣类、匙瓣类、桂瓣类、匙瓣-平瓣类和管瓣类,聚类结果大致按照花径-瓣型-花型分类。14 对 SRAP 引物组合扩增56 个切花菊品种的DNA,共扩增出454 条带,其中多态性带423 条,占扩增带数的 93.17%,多态性含量PIC 值在0.72 ~ 0.89 之间,平均为0.82,说明切花菊品种在分子水平上具有丰富的 遗传多样性。基于SRAP 标记的UPGMA 聚类分析显示：品种间遗传相似系数在0.64 ~ 0.97 之间,将56 个切花菊品种分为平瓣类-匙瓣、桂瓣类和管瓣类,聚类结果大致按照花径-瓣型-花型分类。Mantel 检验相关性系数为0.682,两种聚类结果有相似之处,均能很好体现试验切花菊品种间的遗传关系。     

HPLC-MS/MS快速检测水产品中甲基睾丸酮的研究

用甲基叔丁基醚提取水产样品中的甲基睾丸酮,提取物经C18粉和正己烷净化后,通过电喷雾离子源电离多反应监测(MRM)对甲基睾丸酮作定性和定量分析。结果表明,甲基睾丸酮在1.0～500.0μg/L浓度范围内线性良好(r>0.999);在4.0～200.0μg/kg添加水平下,回收率为80.4～95.2%,相对标准偏差为4.1%～10.5%,检测限为1.0μg/kg(S/N=5)。     

河南省农用地集约利用影响因素计量分析——基于遗传算法-BP神经网络、广义脉冲响应函数的实证研究

基于河南省1978—2012年相关时间序列数据,构建遗传算法-BP神经网络模型,对研究期间河南省农用地集约利用水平进行测算。在此基础上,应用协整理论、误差修正模型、广义脉冲响应函数和方差分解,研究了河南省农用地集约利用与其影响因素的动态响应关系。结果表明,农用地集约利用综合指数和农民人均收入、农业总产值、人均耕地、政策法规存在长期均衡关系;农民人均收入、农业总产值和政策法规对农用地集约利用推动作用长期内更为显著;农民人均收入和政策法规是农用地集约利用预测方差的主要来源,总贡献保持在52%以上,而农业总产值和人均耕地对农用地集约利用预测方差的贡献不足14%。从整体看,河南省农民人均收入和政策法规是影响农用地集约利用的主要因素。最后根据研究结论提出了相关政策建议。     

促进土地承包经营权流转的创新机制研究

分析了我国农村土地流转中存在的问题,提出了通过创新机制促进土地承包经营权流转的具体策略。     

发展坡地农用林业治理农业面源污染

当前由于水土流失导致的农业面源污染问题越来越严重。针对水源地土壤过度营养、坡地绿化率低、森林质量不高等问题,围绕控制农业面源污染,改善农村环境质量这个中心,提出从改善农业生产条件、加强坡岸植被缓冲带建设等方面入手,注重因地制宜,大力发展坡地林业,培育森林资源,最终控制农业面源污染。可见,发展坡地林业对于减缓农业面源污染具有非常重要的意义。