我国蔬菜价格周期性波动规律分析   总被引：2，自引：0，他引：2  

郭力野 《中国蔬菜》2014,1(1):41

近年来,我国蔬菜价格波动频繁,卖难、买贵现象时有发生。本文采用HP 滤波法和BP 滤波法,分析了我国2004～2013 年蔬菜及主要品种的价格波动规律。通过分析得出,我国蔬菜价格呈总体增长的线性趋势,季节性变化特征明显,无明显随机性波动特征;产区集中的耐贮品种具有较明显的价格波动周期,季节性波动相对明显;产区分散的耐贮品种无明显的价格波动周期,季节性波动较明显;大棚菜和叶菜类价格波动受天气因素影响较大,季节性波动明显,无明显周期波动特征。  相似文献   

人类基因组测序在疾病预防和治疗中的应用(英文)     

张力烨 《农业生物技术学报》2013,21(1):1-11

由于在 DNA 测序技术上的重大突破,基因组测序已经成为了医疗中重要的工具。1000 基因组项目和 ENCODE 项目对于基因组中变异和功能提供了全面的注释,这对于测序技术在医疗中的应用将会有巨大的助益。如今测序技术在检测造成罕见孟德尔遗传疾病的突变上取得了巨大的成功。此外,对于癌症基因组的测序能够全面地检测基因组中的各种变异,这为癌症带来了更加准确的分类和更加靶定的治疗方案。相对而言,基因组测序在常见疾病和病毒细菌治疗上的应用还十分有限,但其前景仍非常光明。更加重要的是,了解基因组的信息不仅可以帮助疾病治疗,还能够在疾病预防中发挥巨大的作用(比如,婴儿基因遗传病的提前检查预测)。整个社会仍然需要解决诸如高成本,测序数据处理中对大量计算处理的高硬件需求和不成熟的交流渠道来真正的使测序技术完全在临床医疗中发挥出其作用。但是,这些问题都极可能在不远的将来由新的测序技术,云计算和更好的教育一一解决。本综述着重于介绍了最近几年基因组测序在疾病治疗和预防方面的新应用和新成果。  相似文献   

Chitosan Nanoparticles Attenuate Hydrogen Peroxide-Induced Stress Injury in Mouse Macrophage RAW264.7 Cells     

Zheng-Shun Wen  Li-Jia Liu  You-Le Qu  Xiao-Kun OuYang  Li-Ye Yang  Zi-Rong Xu 《Marine drugs》2013,11(10):3582-3600

This study was carried out to investigate the protective effects of chitosan nanoparticles (CNP) against hydrogen peroxide (H₂O₂)-induced oxidative damage in murine macrophages RAW264.7 cells. After 24 h pre-incubation with CNP (25–200 μg/mL) and chitosan (CS) (50–200 μg/mL, as controls), the viability loss in RAW264.7 cells induced by H₂O₂ (500 μM) for 12 h was markedly restored in a concentration-dependent manner as measured by MTT assay (P < 0.05) and decreased in cellular LDH release (P < 0.05). Moreover, CNP also exerted preventive effects on suppressing the production of lipid peroxidation such as malondialdehyde (MDA) (P < 0.05), restoring activities of endogenous antioxidant including superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) (P < 0.05), along with increasing total antioxidant capacity (T-AOC) (P < 0.05). In addition, pre-incubation of CNP with RAW264.7 cells for 24 h resulted in the increase of the gene expression level of endogenous antioxidant enzymes, such as MnSOD and GSH-Px (P < 0.05). At the same concentration, CNP significantly decreased LDH release and MDA (P < 0.05) as well as increased MnSOD, GSH-Px, and T-AOC activities (P < 0.05) as compared to CS. Taken together, our findings suggest that CNP can more effectively protect RAW264.7 cells against oxidative stress by H₂O₂ as compared to CS, which might be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.  相似文献