天坑森林植物叶-凋落物-土壤C、N、P生态化学计量特征

为探究广西乐业大石围天坑森林群落的C、N、P养分循环特征,比较了天坑内外森林群落的植物叶片-凋落物-土壤C、N、P含量及其化学计量比,采用相关性分析和冗余分析等统计方法研究其内在联系和相互影响。结果表明,与天坑外部森林相比,天坑内部森林植物叶片和凋落物呈现出C低N、P高,土壤为C、N低P高的格局。植物叶片C:N、C:P与凋落物C、N:P显著正相关,植物叶片C与土壤P显著负相关;天坑外部森林的植物叶片N、N:P与土壤N:P显著负相关,植物叶片C:N与土壤C、C:N显著正相关,说明天坑森林内部凋落物的C、P养分可能主要来源于植物叶片,而天坑外部森林的植物叶片C、N主要来自土壤。土壤C:N:P对植物叶、凋落物的C:N:P变化的解释率分别为90.7%和50.6%,其中土壤P对植物叶和凋落物的C:N:P计量特征变化的解释度最高,坑内生境植物对P含量变化更为敏感、坑外植物对于N含量变化更为敏感,表明天坑内部森林可能是P素受限位点、天坑外部森林是N素受限位点。喀斯特天坑内部森林和外部森林植物叶-凋落物-土壤的C:N:P的差异和联系,体现了天坑内外森林群落的养分循环特征和植物群落的适应性。     

Berberine ameliorates DSS-induced intestinal mucosal barrier dysfunction through microbiota-dependence and Wnt/β-catenin pathway

Ulcerative colitis (UC) is an idiopathic, chronic inflammatory disorder of the colon, and it has become one of the world-recognized medical problems as it is recurrent and refractory. Berberine (BBR) is an effective drug for UC treatment. However, the underlying mechanism and targets remain obscure. In this study, we systematically investigated the therapeutic effect and its mechanism of BBR in ameliorating DSS-induced mouse colitis. Expectedly, the colon inflammation was significantly relieved by BBR, and microbiota depletion by antibiotic cocktail significantly reversed the therapeutic effect. Further studies showed that BBR can regulate the abundance and component of bacteria, reestablish the broken chemical and epithelial barriers. Meanwhile, BBR administration dramatically decreased ILC1 and Th17 cells, and increased Tregs as well as ILC3 in colonic tissue of DSS-induced mice, and it was able to regulate the expression of various immune factors at the mRNA level. Moreover, a proteomic study revealed that Wnt/β-catenin pathway was remarkably enhanced in colonic tissue of BBR-treated mice, and the therapeutic effect of BBR was disappeared after the intervention of Wnt pathway inhibitor FH535. These results substantially revealed that BBR restores DSS-induced colon inflammation in a microbiota-dependent manner, and BBR performs its protective roles in colon by maintaining the structure and function of the intestinal mucosal barrier, regulating the intestinal mucosal immune homeostasis and it works through the Wnt/β-catenin pathway. Importantly, these findings also provided the proof that BBR serves as a potential gut microbiota modulator and mucosal barrier protector for UC prevention and therapy.     

两个雌核发育白鲢群体同工酶分析及遗传标记的确定

取源于武汉两个不同渔场两尾白鲢的卵子,经紫外照射遗传物质失活的鲤鱼精子刺激雌核发育和热休克诱导第二极体保留的基因组操作技术,获得了两个不同的人工雌核发育白鲢群体。采用聚丙烯酰胺垂直板电泳技术,分析了这两个不同人工雌核发育白鲢群体（分别称为Hy-G     

具有周期系数和连续时滞的扩散模型的周期解

本文讨论了具有周期系数和连续时滞的竞争扩散模型,得到了保证其存在唯一周期解及全局渐近稳定的充分条件．     

阿维菌素高产菌株的选育及阿维菌素B1的鉴定

自阿维链霉菌(Streptomyces avermitilis ATCC31272)中分离出了3种不同类型的菌株,其中只有产灰色孢子的菌株能产生阿维菌素(Avermectins),摇瓶发酵单位约100μg/mL。经高频电子流诱变和对发酵培养基的改进,选育出Sa-76菌株,其摇瓶发酵单位可达1000μg/mL。从其菌丝体中提取纯化了阿维菌素B₁晶体,其紫外吸收光谱、红外吸收光谱、核磁共振谱(¹HNMR和¹³CNMR)和质谱与国外报道的一致。Sa-76菌株又经2次亚硝基胍诱变,筛选出发酵单位2000μg/mL以上的Sa-76-8菌株。在此基础上,再次用亚硝基胍对Sa-76-8菌株进行了诱变,获得Sa-76-9菌株,结合发酵条件的优化,其发酵单位可高达3500～4000μg/mL。     

蓝粒小麦籽粒糊粉层色素研究初报

观察了蓝粒小麦籽粒灌浆期糊粉层色素形成情况,并分析了蓝粒糊粉层色素的成分。结果表明,在灌浆期,蓝粒小麦籽粒的糊粉层首先是靠近盾片的部分变蓝,而后逐渐向上扩展,在扩展的过程中,可以看到糊粉层着色部位既显蓝色,呈现一定程度的紫红色。蓝粒小麦籽粒糊粉层色素含矢车菊素（Ｄｅｌｐｈｉｎｉｄｉｎ,红色）、飞燕草素（Ｃｙａｎｉｄｉｎ,蓝色）芍药素等８种麦籽粒糊粉层色素含矢车菊素（Ｄｅｌｐｈｉｎｉｄｉｎ,红色）、     

小鼠输精管内转染法建立人组织型纤溶酶原激活剂(tPA)乳腺定位表达生物反应器的研究

外源基因受精卵内显微注射目前仍然是种常用的建立转基因动物的方法,但此方法操作复杂,成本高。因此利用精子作为载体将外源基因带入卵细胞内建立转基因动物成了极具吸引力的方法,并且已有一些成功的报道。虽然该方法简单,但总体来说可重复性较差。我们在建立乳腺定位表达人组织型纤溶酶原激活剂(tPA)小鼠模型中,对此方法做了改进,即将脂质体包裹的外源基因在小鼠输精管及附睾管内转染精子,而非以往的在体外转染,结果:(1)五只转染小鼠,术后10天内共使10只正常母鼠受精;(2)共繁殖出79只首建者小鼠,存活42只;(3)用PCR检测首建者小鼠外源基因的整合,阳性率为7/42(16.67%);(4)用凝胶平板溶圈试验检测5只PCR阳性的雌性首建者小鼠泌乳期乳汁中的活性tPA,3/5表达,表达量在12—20IU/ml之间(约相当于48—80ng/ml);(5)PCR检测4只子一代小鼠外源基因的遗传情况,阳性率为2/4。     

Array-based nano-amplification technique was applied in detection of hepatitis E virus

A rapid method for the detection of Hepatitis E Virus (HEV) was developed by utilizing nano-gold labeled oligonucleotide probes, silver stain enhancement and the microarray technique. The 5'-end -NH(2) modified oligonucleotide probes were immobilized on the surface of the chip base as the capture probe. The detection probe was made of the 3'-end -SH modified oligonucleotide probe and nano-gold colloid. The optimal concentrations of these two probes were determined. To test the detection sensitivity and specificity of this technique, a conservative fragment of the virus RNA was amplified by the RT-PCR/PCR one step amplification. The cDNA was hybridized with the capture probes and the detection probes on microarray. The detection signal was amplified by silver stain enhancement and could be identified by naked eyes.100 fM of amplicon could be detected out on the microarray. As the results, preparation of nano-gold was improved and faster. Development time also was shortened to 2 min. Thus, considering high efficiency, low cost, good specificity and high sensitivity, this technique is alternative for the detection of HEV.     

Effect of arbuscular mycorrhizal fungal inoculation on heavy metal accumulation of maize grown in a naturally contaminated soil

A pot culture experiment was carried out to study heavy metal (HM) phytoaccumulation from soil contaminated with Cu, Zn, Pb, and Cd by maize (Zea mays L.) inoculated with arbuscular mycorrhizal (AM) fungi (AMF). Two AM fungal inocula--MI containing only one AM fungal strain (Glomus caledonium 90036) and MII consisting of Gigaspora margarita ZJ37, Gigaspora decipens ZJ38, Scutellospora gilmori ZJ39, Acaulospora spp., and Glomus spp.--were applied to the soil under unsterilized conditions. The control received no mycorrhizal inoculation. The maize plants were harvested after 10 wk of growth. MI-treated plants had higher mycorrhizal colonization than MII-treated plants. Both MI and MII increased P concentrations in roots, but not in shoots. Neither MI nor MII had significant effects on shoot or root dry weight (DW). Compared with the control, shoot Cu, Zn, Pb, and Cd concentrations were decreased by MI but increased by MII. Cu, Zn, Pb, and Cd uptake into shoots and roots all increased in MII-treated plants, while in MI-treated plants Cu, Zn, and Pb uptake into shoots and Cd uptake into roots decreased but Cu, Zn, and Pb uptake into roots and Cd into shoots increased. MII was more effective than MI in promoting HM extraction efficiencies. The results indicate that MII can benefit HMphytoextraction and, therefore, show potential in the phytoremediation of HM-contaminated soils.