衰老性记忆障碍与脑突触体内游离[Ca~(2 )]_i的相关性

采用行为观察和生化检测相结合的方法 ,在过去工作的基础上 ,研究了 12月龄和 18月龄小鼠学习记忆能力的变化和 18月龄小鼠四个脑区 (海马、大脑皮层、四叠体和小脑 )突触体内 [Ca2 ]i 的水平 ,同时还比较了老年记忆保持良好组与记忆障碍组小鼠的脑钙水平。结果表明 ,随着年龄的增长 ,小鼠的学习记忆能力显著下降 ,上述脑区 (除大脑皮层外 )突触内 [Ca2 ]i 均明显升高 ,其中老年记忆障碍小鼠脑钙水平升高最为显著。提示 ,小鼠衰老性记忆障碍可能与其脑突触体内 [Ca2 ]i 的超载有关。     

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。     

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.     

基于宏基因组学分析湘西腊肉的细菌多样性

目的解析湘西成熟腊肉制品中微生物群落结构和种群丰度。方法采集湖南慈利县、辰溪县和古丈县3个样地成熟腊肉样品,提取样品细菌总DNA,利用454焦磷酸高通量测序法进行测序,并进行生物信息学分析。结果从慈利腊肉获得10 449条优质序列,聚类得到132个OTUs,注释为8个菌门,鉴定出82个属;其中变形菌门为主要细菌类群,占比90.1%;葡萄球菌属为优势菌属,占比47.6%。辰溪腊肉获得10 719条优质序列,聚类得到70个OTUs,归入5个菌门,37个菌属,变形菌门占比54.2%,为优势菌门;葡萄球菌属为第一大菌属,占比65.5%。古丈腊肉获得15 577条优质序列,聚类得到97个OTUs,分属于9个菌门,52个菌属,其中厚壁菌门占比84.5%,为最丰富的类群;葡萄球菌属为优势属,占比71.1%。3地区腊肉样品群落多样性高低依次为辰溪>慈利>古丈,湘西成熟腊肉中优势细菌类群为葡萄球菌,其次为鞘氨醇单胞菌和嗜冷杆菌。鞘氨醇单胞菌在腊肉样品中作为优势菌群为首次报道。结论湘西成熟腊肉中蕴含着丰富的微生物类群,鞘氨醇单胞菌可能与湘西腊肉独特风味形成有一定关联。     

Salmonella Pathogenicity Island 1(SPI-1) at Work

As an indispensable virulence determinant, Salmonella pathogenicity island 1(SPI-1) has gained much attention in host–pathogen interactions. More and more studies on SPI-1 have demonstrated that it is far more complex than the one we used to expect. It not only affects sophisticated activities during infection, including invasion, replication, and host responses, but also extends to other fields like biofilm formation. In addition, mutants in SPI-1 effectors have been explored as vaccines, the effective ways to prevent salmonellosis. The activity of SPI-1 is influenced by many factors which have been widely reported. Investigations on these factors may provide new insights into prevention and treatment of salmonellosis. Therefore, SPI-1 is a tempting issue worthy of further exploration. In this review, we will probe into SPI-1 systematically.     

Biodiesel Potential of Nonfood Plant Resources from Tsinling and Zhongtiao Mountains of China

Forty-nine wild oil plants which are abundant in the Tsinling and Zhongtiao Mountains were investigated and screened as raw material for biodiesel production. The oil content was tested and found to be greatly variable, ranging from 10 to 62.8 %. Fatty acid profiles of their vegetable oils were analyzed, and their acid value, saponification number, and iodine value were found to range from 1.6 to 61.3 mg KOH/g, 128.6 to 225.9 mg KOH/g, and 54.3 to 120.9 g I₂/100 g, respectively. Cetane number, kinematic viscosity, specific gravity, high heating values, and cold filter plugging point of the 49 vegetable-oil methyl esters (MEs) were empirically calculated and were found to vary from 38.8 to 66.6, 2.9 to 4.2 mm²/s, 841.4 to 883.8 kg/m³, 39.0 to 47.5 kJ/g, and ?14.3 to 13.2 °C, respectively. Almost half (25 species) of all the sampled resources were found to be suitable for biodiesel production since the profiles of their vegetable-oil MEs met the major specifications of Chinese and European Union biodiesel standards, GB/T20828 and EN-14214, respectively. Grey relational analysis was used during the optimum-species screening process. The difference between the individual species and the artificial designed ideal species (the best biodiesel plant type in this paper) was calculated and evaluated with the help of grey relational grade, which varied from 0.467 to 0.686. Finally, the selected plants, Prunus salicina Linn. and Amygdalus davidiana (C.) C. de Vos, were considered as the optimal feedstock for biodiesel production.     

Fish biology and biotechnology is the source for sustainable aquaculture

<正>The contribution of aquaculture to global food production and security has been widely acknowledged since the start of the 21st century[1–4].Global aquaculture production has increased continuously over the last five decades,and particularly in China,aquaculture has become the fastest growing and most efficient agri-sector,with production accounting for more than 70%of the world’s aquaculture