胶州湾滨海湿地枯落物分解对土壤活性有机碳含量及其三维荧光特性的影响

通过室内试验模拟胶州湾滨海湿地碱蓬、芦苇、互花米草枯落物的分解过程,测定土壤活性有机碳(可溶性有机碳、微生物生物量碳)含量变化,并利用三维荧光技术对可溶性有机碳(DOC)进行光谱分析.结果表明: 土壤活性有机碳含量呈先增加后降低最终趋于稳定的变化趋势;不同枯落物类型和添加方式对土壤活性有机碳的影响不同,表现为碱蓬＞互花米草＞芦苇,且原状混合＞表面覆盖;光谱分析表明,分解过程各三维荧光光谱的荧光峰数量、荧光中心位置和荧光强度都存在一定差异,添加枯落物后土壤未发现类酪氨酸峰;芳香类蛋白物质占比最高,腐殖质类物质次之.枯落物分解是以微生物分解作用为主导、枯落物性质为本质要素、多重因子综合作用的结果,其对提高土壤活性有机碳含量、增强土壤碳库的稳定性具有促进作用;该过程通过改变DOC的结构和化学组分,提高其在土壤中的迁移转化能力,增强生物可降解性和可利用性,促进微生物内源DOC的产生,加快湿地土壤碳循环.     

基于高速逆流色谱的大极性海参多肽分离方法研究

本文通过对HEMWat溶剂体系中28种常用溶剂系统单相以及整体极性进行系统分析,探讨了无法用常规J型逆流色谱实现对大极性化合物实现有效分离的原因。根据分析结果建立了一种以分离物质理化性质为基础选择潜在改性剂,样品在溶剂系统上相中的溶解程度为判断指标进行筛选逆流色谱溶剂系统改性剂,进而得到适宜的溶剂系统对大极性海参多肽样品进行系统分段方法。经过两步分离,共得到8个随极性分布的海参多肽片段,为海参多肽最佳活性物质的追踪和筛选提供了技术支持。     

New Aspects of Microbial Nitrogen Transformations in the Context of Wastewater Treatment – A Review

Over the past few years, new technologies for nitrogen removal have been developed mainly because of the increasing financial costs of the traditional wastewater treatment technologies. Newly discovered pathways, like the anaerobic oxidation of ammonium (ANAMMOX), and uses for nitrogen removal technologies are under discussion. Processes and technologies such as: Partial nitrification; Single reactor systems for High Ammonium Removal Over Nitrite (SHARON); Anammox; Aerobic/anoxic deammonification; Oxygen Limited Autotrophic Nitrification‐Denitrification (OLAND); Completely Autotrophic Nitrogen Removal Over Nitrite (CANON); wetland based systems, all have a high potential for nitrogen removal. However, the pathways of nitrogen transformation processes are very complex. An understanding of how various environmental factors affect these processes and a sound knowledge of existing, worldwide experience pertaining to these novel technologies are the key if the nitrogen removal rates are to be improved and success is to be realized in full‐scale applications. This review describes the present knowledge of the new treatment technologies for wastewater with high nitrogen loads. Special emphasis is given to the influence of environmental factors and the reactor configuration on the nitrogen transformation process and microbial activity.     

巢蕨配子体的新观察

在不添加任何外源激素的条件下,用水来隔绝空气,即在试管中沉水条件下培养狭翅巢蕨(Neottopteris antrophyoides (Christ) Ching)的孢子,首次成功地诱导出极端简化的雄性配子体,简化程度几乎与被子植物的花粉粒相当,只由1个营养细胞、1条假根和1个精子器组成。本文讨论了在高等植物生活史系统演化方面,环境因素可能起到的作用。     

Eight polymorphic microsatellite markers developed in the green leaf bug,Lygus lucorum Meyer‐Dür (Hemiptera: Miridae)

We developed eight polymorphic microsatellite markers for the green leaf bug, Lygus lucorum Meyer‐Dür. The number of observed alleles per locus in 48 individuals ranged from three to 13, whereas the observed and expected heterozygosities ranged from 0.133 to 0.810 and from 0.236 to 0.886, respectively. Cross‐species amplifications were conducted both within and between generas, and the amplification results indicated that these primers enriched for L. lucorum Meyer‐Dür are species‐specific.     

Physiological and behavioral effects of amphetamine in BACE1−/− mice

β‐Site APP‐cleaving Enzyme 1 (BACE1) is a protease that has been linked to schizophrenia, a severe mental illness that is potentially characterized by enhanced dopamine (DA) release in the striatum. Here, we used acute amphetamine administration to stimulate neuronal activity and investigated the neurophysiological and locomotor‐activity response in BACE1‐deficient (BACE1^?/?) mice. We measured locomotor activity at baseline and after treatment with amphetamine (3.2 and 10 mg/kg). While baseline locomotor activity did not vary between groups, BACE1^?/? mice exhibited reduced sensitivity to the locomotor‐enhancing effects of amphetamine. Using high‐performance liquid chromatography (HPLC) to measure DA and DA metabolites in the striatum, we found no significant differences in BACE1^?/? compared with wild‐type mice. To determine if DA neuron excitability is altered in BACE1^?/? mice, we performed patch‐clamp electrophysiology in putative DA neurons from brain slices that contained the substantia nigra. Pacemaker firing rate was slightly increased in slices from BACE1^?/? mice. We next measured G protein‐coupled potassium currents produced by activation of D2 autoreceptors, which strongly inhibit firing of these neurons. The maximal amplitude and decay times of D2 autoreceptor currents were not altered in BACE1^?/? mice, indicating no change in D2 autoreceptor‐sensitivity and DA transporter‐mediated reuptake. However, amphetamine (30 µm )‐induced potassium currents produced by efflux of DA were enhanced in BACE1^?/? mice, perhaps indicating increased vesicular DA content in the midbrain. This suggests a plausible mechanism to explain the decreased sensitivity to amphetamine‐induced locomotion, and provides evidence that decreased availability of BACE1 can produce persistent adaptations in the dopaminergic system.     

广义Rothermel模型预测平地无风条件下红松蒙古栎林地表混合可燃物的火行为

以帽儿山地区红松-蒙古栎林下地表混合可燃物为材料,进行不同含水率、载量和混合比例的室内点烧试验,观测得到蔓延速率、驻留时间、反应强度、火线强度和火焰长度,并与采用表面积加权法和载量加权法的广义Rothermel模型预测值进行比较.结果表明： 广义Rothermel模型对红松 蒙古栎林下地表混合可燃物的林火蔓延速率、反应强度的预测平均绝对误差分别为0.04 m·min^-1、77 kW·m^-2,预测平均相对误差分别为16%、22%;对驻留时间、火线强度和火焰长度的预测偏低,预测平均绝对误差分别为15.5 s、17.3 kW·m^-1和9.7 cm,预测平均相对误差分别为55.5%、48.7%和24%.这些误差可以看成是用该模型预测同类可燃物相应火行为的误差下限.两种加权算法对模型预测精度影响差异不大,当红松可燃物所占比重较小时,表面积加权法得到的蔓延速率和反应强度预测值精度较高,载量加权法得到的火线强度和火焰长度预测值精度较高;当红松可燃物所占比重较大时,结果则相反.     

发酵床猪粪腐解菌群筛选

在浙江省安吉县采集了相邻的天然灌木林和板栗林土壤,分析土壤水溶性碳(WSOC)、微生物生物量碳(MBC)、易氧化碳(ROC)、水溶性有机氮(WSON)和微生物生物量氮(MBN),并利用核磁共振方法分析土壤总有机碳的波谱特征,研究天然灌木林改造成板栗林对土壤碳库和氮库的影响.结果表明： 天然灌木林改造成板栗林后,土壤中的碱解氮、有效磷和速效钾显著增加,而WSOC、MBC、ROC、WSON和MBN显著下降.天然灌木林和板栗林土壤有机碳以烷基碳和烷氧碳为主.天然灌木林改造成板栗林后,土壤有机碳中的烷氧碳和羰基碳比例显著下降,而烷基碳和芳香碳比例以及A/O-A值和芳香度均显著增加.天然灌木林改造成板栗林并长期集约经营后,土壤活性碳库和氮库含量均显著下降,而土壤碳库的稳定性显著增加.     

Claudin expression in breast cancer: High or low, what to expect?

The evaluation of claudins (CLDNs) expression pattern in tumours can be important to understand breast carcinogenesis. The study of CLDNs became more appealing since it was found that CLDN3 and CLDN4 are putative therapeutic targets for Clostridium perfrigens enterotoxin (CPE), as well as for monoclonal antibody-based therapy. Moreover, the recently characterized CLDN-low molecular subgroup of breast tumours increased the interest in these molecules. Based on these facts, our aim was to explore the pattern of expression of CLDNs among a large series of invasive breast carcinomas. We also analysed the correlation between the combinatorial expression of CLDN3/CLDN4 and classical prognostic factors and biological markers. In addition, we also compared the characteristics of tumours with low expression of CLDN3, CLDN4 and CLDN7, assessed by immunohistochemistry (IHC), and the ones from CLDN-low subgroup of tumours previously defined by genomic assays. The combinatorial analysis of the expression of CLDN3/CLDN4 showed a significant association between high CLDN3/CLDN4 levels and triple-negative tumours, as well as with worse patient outcome. This combined analysis may provide useful information for breast carcinomas, since these two CLDN members are putative therapeutic targets. Comparing tumours with low expression of CLDN3, CLDN4 and CLDN7 with tumours previously referred to as CLDN-low by genomic assays, we demonstrated that the single IHC evaluation of these three specific CLDNs is insufficient to identify the CLDN-low molecular subtype of breast tumours. The analysis of several other molecular markers, such as EMT (epithelial-to-mesenchymal transition) and CSC (cancer stem cell) markers should probably be added to improve the identification of this subgroup of tumours by IHC, which probably are enriched in carcinomas with metaplastic differentiation.