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单室微生物电解池处理黄水产甲烷
No full text为进一步挖掘酿酒副产物黄水的资源化利用空间,构建不锈钢单室微生物电解池(MEC)处理黄水并实现能源回收.以4%的黄水为基质,考察不同外加电压(0.4V、0.6V、0.8V、1.0V)对黄水处理过程中化学需氧量(COD)去除、各有机酸降解、甲烷产生及能量平衡等的影响.结果表明,当外加0.8V电压时,MEC中COD去除率达到94.90%±0.70%,较对照组(AD)的82.00%±0.70%增加了12.90%±0.74%.同时,COD去除负荷达(5.27±0.51)kgm~(-3)d~(-1),是AD(3.45±0.09)kgm~(-3)d~(-1)的1.53倍.对反应中甲烷产生速率和有机酸组分变化分析表明,当外加0.6V电压时,MEC中的甲烷产生速率为(1818.54±145.77)mLL~(-1)d~(-1),比AD(1014.88±121.44)mLL~(-1)d~(-1)增加了78.19%;当外加电压为0.8V时,MEC中的乙醇去除速率为(102.37±14.65)mgL~(-1)h~(-1),是AD组(57.31±10.45)mgL~(-1)h~(-1)的1.79倍;AD组的最高丙酸浓度高达(1436.10±84.42)mg/L,而外加1.0V电压的MEC组,其最高丙酸浓度为(845.57±76.72)mg/L,较之降低了(590.53±7.73)mg/L.当反应周期结束时,AD中残留的乙酸和丙酸浓度分别是MEC(外加0.8V电压)中的93.57和5.31倍.最后,反应器能量平衡分析的结果表明,当外加电压为1.0V时,其能量产生与净能量产生分别达到了(3.93±0.48)kWhkg~(-1)、(3.80±0.48)kWhkg~(-1),较AD组(2.92±0.37)kWhkg~(-1)分别增加了(1.01±0.12)kWhkg~(-1)、(0.88±0.12)kWhkg~(-1),且MEC均获得了较AD组更多的净能量.综上表明该MEC可有效促进黄水处理效率并回收甲烷,其最佳外加电压为0.8V
生活污水有机负荷率对连续流单室无膜微生物电解池性能的影响
No full text连续流微生物电解池能有效应用于污水处理中,为了解不同有机负荷率(OLR)对单室微生物电解池(MEC)性能的影响,采用连续流方式,以生活污水为基质,研究恒定外加电压0.6 V、不同OLR(810、920、1 080、1 484、1 680、2 531、2 780 mg L~(-1) d~(-1))情形下化学需氧量(COD)去除率、甲烷(CH4)产率及能耗等.结果表明,随着OLR增加,COD去除率和能量消耗呈降低趋势,而CH4产率呈增加趋势.实验初期,外加电压为0.6 V,进水COD浓度为200 mg/L,MEC对COD去除率达到70%,而厌氧消化(AD)只能达到41%,此时MEC中CH4含量为8.39%,而AD只有6.44%.实验过程中,外加电压为0.6 V,OLR为2 780 mg L~(-1) d~(-1)时,CH4产率达到了(126.72±0.30)m L L~(-1) d~(-1),而能量消耗为(0.032 0±0.0052)k W h/kg COD.菌群高通量分析结果显示,MEC阳极碳毡的优势菌群为Methanothrix sp.和Geobacter sp.,其丰度分别为39.05%和21.83%,而AD组相应丰度只占2.00%和11.76%.综上,MEC可以在低能耗下有效处理低浓度生活污水并同步产CH4,这为生活污水处理提供了新的思路
活性炭在中高温条件下对玉米秸秆厌氧发酵的影响
No full text为提高玉米秸秆厌氧发酵的产气效果,本文研究活性炭在中温(38℃)和高温(50℃)条件下对玉米秸秆厌氧发酵产甲烷的效果及微生物学机制.结果表明,添加活性炭能显著促进秸秆厌氧发酵产甲烷,中、高温试验组(添加活性炭)的累积产甲烷量分别比对照提高了63%和96%;DGGE的结果显示,高温试验组(添加活性炭)和对照组(未添加活性炭)的发酵液中的优势细菌菌群分别是Clostridiale bacterium和Bacillus,中温对照组发酵液和中温试验组发酵液未发现明显优势菌种.添加活性炭分别有利于氢营养型的甲烷鬃毛菌(Methanosaeta concilii strain)和乙酸营养型的醋酸甲烷八叠球菌(Methanosarcina acetivorans strain),在中温、高温试验组的发酵液中形成优势古菌菌群.中温试验组活性炭载体上的优势古菌菌群为甲烷鬃毛菌(Methanosaeta concilii strain),而高温试验组活性炭载体上的优势古菌菌群主要为甲烷八叠球菌嗜高温菌属(Methanosarcina thermophila strain)
有机荧光纳米颗粒和金纳米颗粒在生化分析及抗菌中的应用研究
No full text传统的荧光分子多数会有聚集诱导淬灭效应 （Aggregation Caused Quenching,ACQ），限制了其应用。聚集诱导发光（Aggregation Induced Emission, AIE）荧光分子不同于传统的荧光分子，在聚集的条件下产生荧光，具有生物相容性好、背景荧光较低等特点。在生化分析中应用 AIE 分子，可以免去在细胞、细菌等荧光定位中多次洗涤去除背景荧光的步骤， 可以实现快速及清晰荧光定位的目的。金纳米颗粒具有比表面积大、易于修饰等特点。其也有较为独特的光学性质，能够通过调节颗粒粒径的大小来实现溶液颜色的变化。 将金纳米颗粒应用于抗菌及可视化检测之中具有更大的优势。因此本论文主要包括两大方面的内容：一部分为荧光定位分析，一部分是抗菌研究。具体包括以下六章：第一章主要介绍聚集诱导发光荧光材料和金纳米颗粒的合成、 理化性质及主要应用。为第二、三、四、五章内容做铺垫。可以更好的体现其用于细胞及细菌定位、抗菌敷料及抗菌纳米材料研究和细菌可视化检测的应用中的优势。第二章主要介绍将聚集诱导发光的分子通过不同的化学修饰， 应用到双光子激发的细胞线粒体及微生物定位中。该类聚集发光的荧光分子能够聚集成 20-40nm 作用的纳米颗粒，通过单光子激发或双光子激发，这些颗粒能够准确定位到细胞线粒体内，实现对线粒体的精准靶向。而且由于细菌与线粒体的相似性，这类纳米颗粒也可以对细菌微生物定位。 值得关注的是利用此类荧光染料可以省去对生物样本染色后需要反复洗涤的步骤，保证了荧光强度不被洗涤步骤所影响。这对于临床生物成像避免背景荧光的出现具有重要的意义。第三章主要介绍利用抗生素中间体修饰的金纳米颗粒和静电纺丝技术结合，研发了一种可以对抗多药耐药菌感染的伤口敷料。 首先将抗生素中间体通过原位合成修饰到金纳米颗粒上，这种金纳米颗粒具有很强的抗菌效果，不仅对普通菌株有杀菌作用，还可以对抗多药耐药细菌。然后依托静电纺丝平台，将金纳米颗粒纺入静电纺丝膜中， 这种敷料膜能够对细菌感染的动物伤口模型有很好的治疗作用。第四章主要介绍利用氨基糖修饰的金纳米颗粒对抗超级细菌的研究。 细菌肽聚糖层是由氨基糖类连接而成的。通过原位合成的方法，将氨基糖修饰到金纳米颗粒的表面。这种纳米颗粒能破坏细菌细胞壁，增加细胞壁的通透性，从而起到抗菌作用。这种纳米颗粒不仅可以杀死普通细菌，还可以对耐多种抗生素的超级细菌有很好的抑制作用。第五章主要介绍利用金纳米颗粒的光学特性， 构建了一种基于金纳米颗粒的细菌传感器。将 D-氨基酸 （D-丙氨酰-D-丙氨酸）作为保护剂修饰到金纳米颗粒表面。文献报道，D-型氨基酸可以被细菌利用，合成细菌肽聚糖层的肽桥。这种金纳米颗粒与细菌孵育以后，会使纳米颗粒聚集在细菌的表面，溶液的颜色也会由红色变为蓝色，从而得知有细菌的存在。我们同时也合成了 L-型氨基酸修饰的金纳米颗粒，经过与细菌孵育以后，L 型氨基酸修饰的金纳米颗粒没有变色和发生聚集现象。利用 D-氨基酸修饰的金纳米颗粒可以达到可视化检测细菌的目的。第六章为总结和展望。主要总结了本论文的内容和主要的创新点，并且对后续可能要继续探讨和延续的工作进行了讨论和展望
黄酮醇的合成新方法研究
No full text黄酮醇,即3-羟基黄酮，广泛存在于植物界中,具有抗肿瘤、抗病毒、抗氧化、降血脂等多种生物活性；黄酮醇及其衍生物作为荧光探针、太阳能电池材料，也显示出优良的物理化学特性。天然黄酮醇的数量及种类有限，而且提取分离困难，故化学合成是大量获得结构多样性黄酮醇的重要手段。现有合成方法普遍存在原料制备难度大、底物适应性差、反应条件苛刻、对5-取代黄酮醇合成的选择性及收率差等缺点。本论文致力于发展高效、底物适应性强的黄酮醇合成新方法。第一部分建立了以有机碱为催化剂、苯乙酮和苯甲醛为原料、水相中实现了一锅法合成黄酮醇的方法，并对机理进行了探讨。第二部分在前一部分研究的基础上，将有机碱固载于SBA-15介孔材料上，初步实现了非均相催化黄酮醇的选择性合成，取得了如下结果：（1）建立了一种高效、便捷、底物适应性强的黄酮醇合成新方法。以2￠-羟基苯乙酮和苯甲醛为原料，吡咯烷为催化剂，水作溶剂，室温下一锅法合成了35个黄酮醇 （收率30%~91%）。该方法弥补了Algar-Flynn-Oyamada（AFO）反应对合成5-取代黄酮醇的局限性，拓展了底物的适应性。（2）通过LCMS动力学研究、中间体捕获、以及同位素跟踪等分析，提出了可能的反应机理。苯乙酮与苯甲醛在吡咯烷作用下，产生LUMO活化的亚胺离子活性中间体T2，推测该亚胺离子中间体可与空气中的氧气作用经一个较长的诱导期引发自由基并产生过氧化氢，由此导致两个可能的路径：Path 1）该自由基迅速关环、氧化成黄酮醇；Path 2）与AFO反应类似，亚胺离子（或查尔酮）在过氧化氢作用下产生环氧化中间体，进而生成橙酮和黄酮醇。吡咯烷存在下，Path 1为主要路径，这就是本方法可以提高5-取代黄酮醇选择性的主要原因。（3）采用本课题组前期建立的芳基保护基团法，制备了多种有机碱功能化SBA-15型介孔材料。将这些材料用于催化苯乙酮与苯甲醛，在无溶剂条件下，通过温度调控初步实现了黄酮醇或橙酮的选择性合成。关键词：黄酮醇合成；吡咯烷催化；机理研究；有机功能化SBA-15；选择性控
Differential uptakes of different forms of soil nitrogen among major tree species in subalpine coniferous forests of western Sichuan, China
No full text在陆地生态系统中,植物对土壤有机氮(主要指氨基酸)的获取是一个普遍的生态学现象,然而植物对土壤有机氮的吸收速率及土壤有机氮在植物养分供应中所占比例仍不清楚。为探究土壤无机氮和有机氮对西南高寒森林植物氮源的贡献效应,以川西亚高山针叶林两个主要树种云杉(Picea asperata)和红桦(Betula albo-sinensis)的幼苗为研究对象,采用稳定同位素标记法对K~(15)NO_3、~(15)NH_4Cl和(U-~(13)C_2/~(15)N)甘氨酸3种氮素进行示踪,分析了两个树种对无机氮(NH_4~+-N和NO_3~--N)和有机氮(甘氨酸)的吸收速率及其差异。结果显示:(1)云杉和红桦幼苗在施加同位素标记物2 h后,两种幼苗细根的~(13)C和~(15)N均出现明显的富集现象,表明两种树种幼苗均能吸收甘氨酸。(2)与甘氨酸和NH_4~+-N相比,云杉和红桦幼苗对NO_3~--N有显著的偏好吸收,其吸收速率为NH_4~+-N和甘氨酸吸收速率的5-10倍。(3)两个树种的幼苗对甘氨酸也有较高的吸收速率,其吸收速率高于对NH_4~+-N的吸收速率,表明土壤有机氮(如氨基酸)也是亚高山针叶林植物养分获取的重要氮源
动物学类英文学术期刊编辑加工中的常见问题——以《亚洲两栖爬行动物研究》(英文版)为例
No full text提高国际影响力和竞争力一直是中国英文学术期刊发展的战略目标。而要实现这一重要目标,首先就要提高期刊的编辑加工水平。笔者以《亚洲两栖爬行动物研究》(英文版)为实例,针对动物学类的英文学术期刊,就时态运用、从句结构、物种名称3方面,探讨了实际编辑工作中的常见问题
Dehydration induced transcriptomic responses in two Tibetan hulless barley (Hordeum vulgare var. nudum) accessions distinguished by drought tolerance
No full textBackground: The harsh environment on the Qinghai-Tibetan Plateau gives Tibetan hulless barley (Hordeum vulgare var. nudum) great ability to resist adversities such as drought, salinity, and low temperature, and makes it a good subject for the analysis of drought tolerance mechanism. To elucidate the specific gene networks and pathways that contribute to its drought tolerance, and for identifying new candidate genes for breeding purposes, we performed a transcriptomic analysis using two accessions of Tibetan hulless barley, namely Z772 (drought-tolerant) and Z013 (drought-sensitive). Results: There were more up-regulated genes of Z772 than Z013 under both mild (5439-VS-2604) and severe (7203VS-3359) dehydration treatments. Under mild dehydration stress, the pathways exclusively enriched in droughttolerance genotype Z772 included Protein processing in endoplasmic reticulum, tricarboxylic acid (TCA) cycle, Wax biosynthesis, and Spliceosome. Under severe dehydration stress, the pathways that were mainly enriched in Z772 included Carbon fixation in photosynthetic organisms, Pyruvate metabolism, Porphyrin and chlorophyll metabolism. The main differentially expressed genes (DEGs) in response to dehydration stress and genes whose expression was different between tolerant and sensitive genotypes were presented in this study, respectively. The candidate genes for drought tolerance were selected based on their expression patterns. Conclusions: The RNA-Seq data obtained in this study provided an initial overview on global gene expression patterns and networks that related to dehydration shock in Tibetan hulless barley. Furthermore, these data provided pathways and a targeted set of candidate genes that might be essential for deep analyzing the molecular mechanisms of plant tolerance to drought stress
A novel method for synthesis of alpha-spinasterol and its antibacterial activities in combination with ceftiofur
No full textIn this study, we designed a novel method of the synthesis of alpha-spinasterol from commercially available stigmasterol and explored the combinational effect of the alpha-spinasterol with ceftiofur in vitro against S. pullorum cvcc533, S. pneumoniae CAU0070, E. coli and S. aureus. alpha-Spinasterol was obtained by a key reaction of Bamford-Stevens reaction with a desirable yield for five steps. The combination of alpha-spinasterol and ceftiofur showed stronger synergetic effect against the four pathogenic strains compared with that of stigmasterol and ceftiofur alone. In time-kill analyses, at concentrations above the MICs, ceftiofur in combination with alpha-spinasterol exhibited time-dependency and concentration-dependency comparing to time dependency with ceftiofur alone. We conclude that the combination usage of alpha-spinasterol and ceftiofur is an effective and promising strategy against the four pathogenic bacterial strains in vitro. (C) 2017 Published by Elsevier B.V
Characterization of the temporal and spatial expression of wheat (Triticum aestivum L.) plant height at the QTL level and their influence on yield-related traits
No full textThe temporal and spatial expression patterns of stable QTL for plant height and their influences on yield were characterized. Plant height (PH) is a complex trait in wheat (Triticum aestivum L.) that includes the spike length (SL) and the internode lengths from the first to the fifth internode, which are counted from the top and abbreviated as FIRITL, SECITL, THIITL, FOUITL, and FIFITL, respectively. This study identified eight putative additive quantitative trait loci (QTL) for PH. In addition, unconditional and conditional QTL mapping were used to analyze the temporal and spatial expression patterns of five stable QTL for PH. qPh-3A mainly regulated SL, FIRITL, and FIFITL to affect PH during the booting-heading stage (BS-HS); qPh-3D regulated all internode lengths to affect PH, especially during the BS-HS; before HS, qPh-4B mainly affected FIRITL, SECITL, THIITL, and FOUITL and qPh-5A.1 mainly affected SECITL, THIITL, and FOUITL to regulate PH; and qPh-6B mainly regulated FIRITL to affect the PH after the booting stage (BS). qPhdv-4B, a QTL for the response of PH to nitrogen stress, was stable and co-localized with qPh-4B. All five stable QTL, except for qPh-3A, were related to the 1000 kernel weight and yield per plant. Regions of qPh-3A, qPh-3D, qPh-4B, qPh-5A.1, and qPh-6B showed synteny to parts of rice chromosomes 1, 1, 3, 9, and 2, respectively. Based on comparative genomics analysis, Rht-B1b was cloned and mapped in the CI of qPh-4B. This report provides useful information for fine mapping of the stable QTL for PH and the genetic improvement of wheat plant type