咖啡因与早中期早产儿发生代谢性骨病的相关性

目的探讨咖啡因与早中期早产儿发生代谢性骨病(MBD)的相关性。方法纳入226例胎龄≤34周的早产儿,记录其MBD的发生情况。比较MBD早产儿与非MBD早产儿的产前因素、出生情况、住院期间情况、应用咖啡因等资料,并采用Logistic回归模型分析影响早中期早产儿发生MBD的危险因素,以及咖啡因治疗持续时间累积剂量与早中期早产儿发生MBD的相关性。结果226例早中期早产儿中发生MBD 101例。MBD组和非MBD组之间胎龄、出生体重、合并宫内生长发育迟缓情况、住院时间、抗生素应用时间、应用静脉营养时间、机械通气时间、咖啡因应用剂量、咖啡因应用持续时间、咖啡因累积剂量比较,差异均有统计学意义(均P<0.05)。Logistic回归分析显示小胎龄、低出生体重、咖啡因应用持续时间长、咖啡因累积剂量大均是早中期早产儿发生MBD的独立危险因素(均P<0.05)。当咖啡因累积剂量达700 mg·d/kg或持续应用咖啡因时间达50 d时,早中期早产儿的MDB发生率均高达90%以上。结论早中期早产儿容易发生MBD,应用咖啡因的累积剂量越大、持续时间越长者MBD发生的风险越高。

沼液施用方式对桃园土壤理化性状及桃树生长和果实品质的影响

该研究通过叶面喷施和根部灌施2种不同施用方式在桃园施用效果的研究,分析不同施用方式及不同施用量对桃树生长、果实品质及土壤理化性状的影响,结果表明:在桃树初花期、幼果期、果实膨大期、着色期,用60%的沼液喷施,桃树的单枝叶片数、新生枝长度、叶面积、百叶厚、百叶重、茎粗分别比清水对照增加52.1%、38.2%、32.9%、11.6%、12.2%、30.8%;单果重、果实硬度、可溶性固形物、Vc含量分别比清水对照增加26.7%、20.8%、30.6%、56.5%,可滴定酸含量下降49.8%,优质果率提高41.3%。沼液灌施60 kg/株土壤速效N、P、K、有机质含量分别增加36.4%、204.7%、205.4%和31.8%,土壤容重下降20.8%。

Ecological effects of crude oil residues on the functional diversity of soil microorganisms in three weed rhizospheres

Ecological effects of crude oil residues on weed rhizospheres are still vague. The quantitative and diversity changes and metabolic responses of soil-bacterial communities in common dandelion （Taraxacum officinale）, jerusalem artichoke （Silphiurn perfoliatum L.） and evening primrose （A colypha australis L.） rhizospheric soils were thus examined using the method of carbon source utilization. The results indicated that there were various toxic effects of crude oil residues on the growth and reproduction of soil bacteria, but the weed rhizospheres could mitigate the toxic effects. Total heterotrophic counting colony-forming units （CFUs） in the rhizospheric soils were significantly higher than those in the non-rhizospheric soils. The culturable soil-bacterial CFUs in the jerusalem artichoke （S. perfoliatum） rhizosphere polluted with 0.50 kg/pot of crude oil residues were almost twice as much as those with 0.25 kg/pot and without the addition of crude oil residues. The addition of crude oil residues increased the difference in substrate evenness, substrate richness, and substrate diversity between non-rhizospheric and rhizospheric soils of T. officinale and A. australis, but there was no significant （p〉0.05） difference in the Shannon＇s diversity index between non-rhizospheric and rhizospheric soils of S. perfoliatum. The rhizospheric response of weed species to crude oil residues suggested that S. perfoliatum may be a potential weed species for the effective plant-microorganism bioremediation of contaminated soils by crude oil residues.