Photoreactivation of Escherichia coli and Yersinia enterolytica after Irradiation with a 222 nm Excimer Lamp Compared to a 254 nm Low‐pressure Mercury Lamp

Photoreactivation of Escherichia coli ATCC 11229 and Yersinia enterolytica ATCC 4780 after irradiation with a 222 nm krypton‐chloride excimer lamp compared to a 254 nm mercury lamp was investigated under laboratory conditions. The bacteria samples were irradiated each with different doses of both wavelengths. After irradiation one sample of the bacteria was illuminated with fluorescent light, the other sample was stored in darkness to prevent photoreactivation. The inactivation curves were determined. Without photoreactivation, an irradiation of 69 J/m² at 254 nm was sufficient for a 4 log reduction for E. coli, and only 59 J/m² for Y. enterolytica. To get a 4 log reduction with following photoreactivation, 182 J/m² were necessary for E. coli and 180 J/m² for Y. enterolytica. After irradiation with the 222 nm excimer lamp the ratios were different. Without photoreactivation, an irradiation of 106 J/m² at 222 nm was sufficient for a 4 log reduction for E. coli and 88 J/m² for Y. enterolytica. With photoreactivation 161 J/m² were necessary for E. coli to get a 4 log reduction and 117 J/m² for Y. enterolytica. When the photoreactivation after irradiation is excluded, the mercury lamp with 254 nm clearly shows better results regarding inactivation. Whereas, when included, the excimer lamp with 222 nm wavelength obviously shows better results.     

阿尔金山东段山前砾石钙膜累积速率及其在估算断层活动年代方面的应用

干旱－半干旱地区冲洪积物顶面土壤中发育的砾石钙膜含有明显的年龄信息,其工及由统计计算得到的累积速率可用来估算所在冲洪积物或土壤的形成年代。     

氢化物原子荧光法测定含铀岩石中微量硒

本文介绍了氢化物原子荧光法测定含铀岩石中微量硒的方法。测定下限为０．０１μｇ／ｇ，测量精度（２×１０－７）ＲＳＤ为６．６３％。方法灵敏度高、快速、操作简便。本方法也适用于一般岩石样品中微量硒的测定。     

Clausthalite in coal

A lead selenide mineral, tentatively identified as clausthalite (PbSe) based on optical microscopy, scanning electron microscopy with energy-dispersive X-ray (EDAX), electron microprobe, and scanning proton microprobe (SPM), has been described in a number of coals. While clausthalite has been mentioned as a possible source of Se in coal, it is present in such small quantities and sizes, that the mineral identification has not been absolutely confirmed. The mineral specimens examined in this study would contribute, not only to the Pb and Se concentrations in the coal, but also, in at least one case, to Hg concentrations.     

螺旋藻多糖的积累与抗肿瘤作用的研究

在不同温度和光强下培养极大螺旋藻438(Spirulina maxim438),得到其积累多糖规律为:不利于螺旋藻生长的温度、光照条件,会促进胞外多糖EPS(extracellular polysaccharide,EPS)的分泌,而螺旋藻最适生长条件(30℃,5000lx)与胞内多糖IPS(intracellular polysaccharide,IPS)积累的条件一致。MTT(四甲基偶氮唑盐)法体外实验证明IPS和EPS对人宫颈癌Hela细胞有抑制作用,最佳作用浓度分别为80μg/mL,100μg/mL。Caspase-3试剂盒检测经两种多糖作用后Hela细胞Caspase-3酶的变化,结果显示:处理组比对照组Caspase-3酶活性有明显提高,预示着多糖抑制肿瘤细胞的机制可能是通过Caspase途径,引起细胞的凋亡。     

Bioindication of Gold by Aquatic Bryophytes

As arsenopyrite is frequently present in auriferous deposits, concentrations of gold were measured in aquatic bryophytes collected from streams in zones of arsenic mineralization in the Polish and Czech Sudety Mountains. Data were compared with analyses of aquatic bryophytes from streams in non As mineralization areas with only background concentrations of Au. The highest contents of Au in bryophytes surpass the background concentration of this element in plants and are found in areas characterized by the presence of arsenopyrites.     

Effects of fungal infection on lipid extract composition of higher plant remains: comparison of shoots of a Cenomanian conifer, uninfected and infected by extinct fungi

The lipid fraction extracted from uninfected shoots of a fossil conifer, Frenelopsis alata, was analysed by gas-chromatography–mass-spectrometry, and compared with shoots of the same conifer infected by extinct epiphyllous fungi, so as to study the effects of fungal infection on the chemical composition of extracts from higher plant remains. The extracts from the uninfected shoots appeared to be composed of (i) common constituents of higher plant lipids such as n-alkanes and fatty acids, (ii) elemental sulphur, and (iii) substantial amounts of terpenoids characteristic of conifers, such as cadalene, beyerane, dehydroabietane and related compounds. Comparison of this extract with that of fungal-infected shoots revealed, in addition to the aforementioned compounds, the presence of substantial amounts of hydroxysuccinic acid and functionalised benzoic compounds that were interpreted as degradation products of lignin by fungi. This study afforded preliminary indications of the composition of extracts from higher plant remains infected by fungi.     

累积危险度的动态演化及其与强震的关系

完善了累积危险度的强震危险地点跟踪预测方法,并对１９８９看以来首都圈及邻近地区累积危险度的演化进行了分析。结果表明,累积危险度的演化过程,反映了地震孕育及构造应力活动的过程;２次６级地震前,均出现累积危险度数值增大,震后扩散－消退;累积危险度高值区及其边缘地国可能发震地点。     

Potential source and diagenetic signatures of oceanic dissolved and particulate organic matter as distinguished by lipid biomarker distributions

Potential biogenic sources of ultrafiltered dissolved and suspended particulate organic matter (UDOM and POM, respectively) from the Sargasso Sea (SS) and North Central Pacific (NCP) Ocean were investigated using lipid biomarker compounds. Organic carbon (OC) concentrations were ~ 20–40 times greater in UDOM than POM and decreased with depth. However, total OC-normalized lipid concentrations were 2–3 orders of magnitude higher in POM than in UDOM. Particulate total lipids decreased 3–10-fold with depth, compared to 10–20% for dissolved total lipids. Total fatty acids (FA), the most abundant lipids, showed similar patterns as total lipids, comprising ~ 62–88% of the total lipids analyzed in UDOM and ~ 57–84% in POM.FA were dominated by straight-chain saturated compounds followed by monounsaturated, polyunsaturated, and branched FA. Polyunsaturated FA were enriched in POM vs. UDOM and in surface vs. deep waters for both UDOM and POM, likely reflecting the algal origins and greater reactivity of surface-derived materials. In both UDOM and POM, sterols of planktonic origin dominated, including cholest-5-en-3β-ol (C₂₇Δ⁵), 24-methylcholesta-5,24(28)E-dien-3β-ol (C₂₈Δ^5,24(28)) and 24-ethylcholest-5-3β-ol (C₂₉Δ⁵), with varying contributions from cholesta-5,22E-3β-ol (C₂₇Δ^5,22), 24-methylcholesta-5,22E-3β-ol (C₂₈Δ^5,22) and 24-ethylcholesta-5,22E-3β-ol (C₂₉Δ^5,22).Factor analysis of lipid biomarkers showed major differences between the UDOM and POM pools and for each pool as a function of depth, but not between the SS and NCP. While UDOM and POM biomarkers were both dominated by autochthonous sources, differences between the two pools suggest potential effects from some combination of source and diagenetic factors. The lipid biomarker data are further evaluated relative to previous studies of radiocarbon (¹⁴C) and elemental (C:N:P) characteristics of UDOM and POM in the SS and NCP.     

基于地形地貌因子的大关县堆积层滑坡孕育规律研究

为了揭示复杂山区堆积层滑坡的孕育规律,本文基于大关地区98处堆积层滑坡的基础资料,利用综合影响指数分析法,展开地形地貌因子对滑坡发育程度影响指数的分析研究,划分不同因素对滑坡发育的影响指数等级。不同地形地貌条件对堆积层滑坡发育、发生的影响程度差异很大,高差中等（60～90m）、坡向北东、西向（NE,W）的凸型（T）、缓（21～35）斜坡最利于滑坡的发育。在分析结果的基础上,初步建立滇东北山区基于地形地貌因素的堆积型滑坡发育程度（条件）评价标准,为地质灾害调查提供一种快速判别不稳定斜坡发育程度的方法。