扬子鳄消化道Ghrelin免疫活性细胞的分布及其在冬眠期的密度变化

目的 研究扬子鳄（Alligator sinensis）消化道中生长素释放肽ghrelin免疫活性（IR）细胞的分布、组织定位及其在冬眠期的变化.方法 应用链霉亲和素-生物素-过氧化物酶复合物（SABC）免疫组织化学方法结合生物统计学分析.结果 Ghrelin-IR细胞在扬子鳄的小胃密度最高,在胃贲门部、胃体和胃幽门部有少量分布,主要位于胃腺上皮细胞之间.在食管、十二指肠、空肠、回肠和直肠中均未检测出ghrelin-IR细胞.冬眠期小胃ghrelin-IR细胞显著性减少（P〈0.01）,其它部位无显著性变化（P〉0.05）.结论扬子鳄消化道ghrelin-IR细胞的分布同其它动物有相似之处,也有其一定的特异性.Ghrelin在扬子鳄冬眠期的代谢变化和能量稳态的调节中起重要作用.     

Adhesion of osteoblast-like cell on silicon-doped TiO2 film prepared by cathodic arc deposition

Silicon-doped TiO₂ (Si–TiO₂) and pure TiO₂ films were deposited on titanium substrates by cathodic arc deposition technique. The surface characteristics of the films, such as surface topography, elemental composition and wettability, were studied. About 4.6 % Si was incorporated into the Si–TiO₂ films with a water contact angle of about 83°. The adhesive behaviors of osteoblast-like MG63 cells on both films were investigated through cell counting assay, immunocytochemistry, real-time PCR and western blotting analysis. Cells cultured on the Si–TiO₂ films had a greater cellular viability, stronger cytoskeleton and focal adhesion, and more cellular spreading than those on the pure TiO₂ films. Moreover, the expression levels of integrin β1 and focal adhesion kinase (FAK) genes, FAK and the phosphorylation of FAK proteins were up-regulated in cells cultured on the Si–TiO₂ films. These results indicated that the Si–TiO₂ films possess significantly enhanced cytocompatibility and provide potential solutions for the surface modification of implants in the future.     

Influences of low-head dams on the fish assemblages in the headwater streams of the Qingyi watershed, China

The influences of low-head dams on the fish assemblages were examined in this study, using fish data collected in six treatment and five reference sites at three low-head dams in the headwater streams of the Qingyi watershed, China. Comparing with those in the reference sites, local habitat variables were significantly altered by low-head dams in the treatment sites, involving wider channel (only in the impoundment area), deeper water and slower flow. Fish species richness varied significantly across seasons, not across site categories, suggesting that these low-head dams did not alter species richness. However, significant decreases in fish abundance and density were observed in the impoundment areas immediately upstream of dams, but not in the plunge areas downstream. Fish assemblage structures kept relative stability across seasons, and their significant difference between-site was only observed between the impoundment areas and the sites far from dams upstream. This variation in assemblage structures was due to the differing relative abundance of some co-occurring species; more lentic but less lotic fish was observed in the impoundment areas. The spatial and temporal patterns of fish assemblages were correlated with local habitat in this study area. Wetted width had negative correlation with fish species richness, abundance and density, respectively. Water temperature also positively affected species richness. In addition, wetted width, water depth, current velocity and substrate were the important habitat variables influencing assemblage structures. Our results suggested that, by modifying local habitat characteristics, low-head dams altered fish abundance and density in the impoundment areas immediately upstream of dam, not in the plunge areas immediately downstream, and thereby influenced fish assemblage structures in these stream segments.     

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae): a new species from Zhejiang Province, China

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae), a new species restricted to lead–zinc mining areas in Zhejiang Province, China, is described and illustrated. This taxon belongs to sect. Sedum (H. Ohba) S.H. Fu based on the adaxially gibbous carpels and follicles. It superficially resembles S. alfredii Hance and three other Sedum species found in the same area, but differs from these other taxa in bearing 4-merous flowers. Differences in geographical distribution, growth habit, phenology, macromorphology, leaf and stem anatomy, as well as seed micromorphology among S. plumbizincicola, S. alfredii and other related taxa in the genus Sedum are also reported. nrDNA internal transcribed spacers (ITS) sequences from seven populations of S. plumbizincicola support the recognition of this as a taxonomic entity distinct from S. alfredii.     

安徽新安江干流滩涂湿地草本植物区系及物种多样性

以新安江干流(安徽段)滩涂湿地草本植物群落为研究对象,探讨其区系组成及不同江段物种多样性的变化规律.结果表明:(1)该区共有草本被子植物48科、131属、194种(含种下分类单位);以禾本科(Gramineae)、莎草科(Cyperaceae)、菊科(Compositae)和蓼科(Polygonaceae)为优势科;以蓼属(Polygonum)、莎草属(Cyperus)、大戟属(Euphorbia)和蒿属(Artemisia)等为优势属,属的组成相对较为分散,寡种属和单种属占总属数的97.7％;(2)从分布区类型看,科以世界分布占明显优势(43.8％);属的分布区类型以泛热带分布最多(30.5％),其次是世界分布(26.0％),总体上热带成分略多于温带成分(57/40);表明该区草本植物区系地理成分较为复杂,分布区类型多样,具有热带、亚热带与暖温带的多重性质,但以亚热带性质为主;(3)各滩涂湿地植物群落的建群种、优势种及伴生种的种类等组成特征均存在一定差异,狗牙根(Cynodon dactylon)、双穗雀稗(Paspalum distichum)和假俭草(Eremochloa ophiuroides)等为滩涂湿地的主要优势种;江段干流不同流域滩涂湿地草本植物群落的α多样性的变化格局与丰富度指数的变化格局比较一致,总体上呈现逐渐减小的趋势,表现为上游＞中游＞下游;与之相反,植物群落的β多样性——相异性系数和Cody指数总体上呈现上升的格局.这种多样性格局的成因需要进一步分析和探讨.     

茉莉酸对棉花单宁含量和抗虫相关酶活性的诱导效应

以植物生长调节物茉莉酸(Jasmonic acid,JA)为诱导子,以常规棉为研究对象,探讨了外源茉莉酸对棉花幼苗单宁和蛋白酶抑制素以及其它抗虫相关酶活性诱导的浓度依赖性和持久性,讨论了棉花抗虫相关物质的抗虫效果.结果表明,0.01、0.1和1.0 mmol/L茉莉酸都能在2周内诱导棉花单宁和胰蛋白酶抑制素(Proteinase inhibitors,PIs)含量增加,诱导多酚氧化酶(Polyphenol oxidase,PPO)、苯丙氨酸解氨酶(Phenylalanine ammonia-lyase,PAL)、过氧化物酶(Peroxidase,POD)和过氧化氢酶(Catalase,CAT)活性升高.对3种浓度茉莉酸的诱导效应进行分析表明,0.1 mmol/L茉莉酸对于诱导PIs、PPO、POD和CAT最有效,0.1和1.0 mmol/L茉莉酸对于诱导棉花单宁和苯丙氨酸解氨酶等效,二者的诱导效应均高于0.01 mmol/L.对茉莉酸诱导抗性的持久性进行分析表明,最佳诱导效应发生的时间各不相同:POD活性在JA处理后第1天最高,随后呈下降趋势,PIs和单宁含量分别在JA处理后第7天和第14天达最大值;JA处理后第1天和第7天的PPO活性无明显差异,但明显高于第14天;JA处理后第7天和第14天的PAL活性无明显差异,但明显高于第1天;JA处理后第1、7和14天棉花叶片的CAT活性均无明显差异.以上结果表明,茉莉酸可通过增加棉叶单宁和PIs含量、提高棉叶PAL、PPO、POD和CAT活性等增强棉花幼苗的抗虫性.     

我国特有植物青檀遗传结构的ISSR分析

青檀是我国特有的第三纪残遗植物,是宣纸纤维来源的重要原材料,现已被列入国家Ⅲ级保护植物。采用简单序列重复区间扩增多态性(ISSR)标记技术,对采自27个地理种群的628个青檀个体的遗传多样性和遗传结构进行了检测。8对引物共得到66个清晰的扩增位点,其中多态性位点63个,多态性位点百分率为95.45%。分析结果表明,青檀在物种水平上具有很高的遗传多样性(PPB=95.45%、Ao=1.9545、Ae=1.5729、He=0.3335、I=0.4980、Hb=0.3437)。在种群水平上的遗传多样性(PPB=69.98%、Ao=1.6998、Ae=1.4449、He=0.2561、I=0.3793、Hb=0.2656)和种群间遗传分化水平(Gst=0.23,Ф_ST=0.25)均处于中等水平。华北地区(30°-42°N)和华南地区(22°-30° N)青檀的遗传多样性和遗传结构的差异并不显著。古老的起源历史、较广的分布范围、异交的繁育系统、风媒种子、长命的生活史以及华南和华北地形和植被的差异可能是导致青檀目前遗传格局的主要原因。结合叶绿体序列(cpDNA)序列的遗传结构特征对青檀的保护策略进行了探讨。     

光照强度对大花旋蒴苣苔叶形态和生理指标的影响

以复苏植物大花旋蒴苣苔(Boea clarkeana)为盆栽实验材料,通过梯度遮光处理,研究不同光照强度(100%、80%、60%、40%和20%透光率)和不同处理时间(30、60、90、120和150d)对大花旋蒴苣苔叶生长指标和生理指标的影响。结果表明:随着光照强度的减弱,大花旋蒴苣苔叶的各生长指标(叶片长、叶片宽、叶柄长、叶柄直径以及叶面积)呈现先增大后减小的趋势,透光率为60%时达到最大值;全光照(100%透光率)时,大花旋蒴苣苔表现出明显的外伤症状,透光率为80%和20%时,分别表现出中度伤害和轻度伤害,透光率为40%和60%时,未出现明显的外伤症状;过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和过氧化物酶(POD)3种抗氧化酶活性均较低且随着光强减弱呈现先降低后升高的趋势,随着处理时间的延长呈先上升后下降的趋势,全光照时抗氧化酶的活性最大,透光率60%处理下酶活性相对较低;丙二醛(MDA)含量、脯氨酸(Pro)含量和质膜透性随着光强减弱呈先降低后升高的趋势,随着处理时间的延长显著升高;叶绿素含量随着光强减弱呈逐渐上升的趋势,随着处理时间的延长先降低后升高。分析表明,40%～60%的透光率有利于大花旋蒴苣苔的生长,强光和弱光对大花旋蒴苣苔的生长均不利。     

N+ ion beam implantation of tannase-producing Aspergillus niger and optimization of its process parameters under submerged fermentation

Low-energy ion implantation as a novel mutagen has been increasingly applied in the microbial mutagenesis for its higher mutation frequency and wider mutation spectra. In this work, N⁺ ion beam implantation was used to enhance Aspergillus niger TA9701 in tannase yield. The optimization of process parameters under submerged fermentation was carried out to further improve the tannase yield of the mutant, Aspergillus niger J-T18. The results indicate that an excellent mutant J-T18 with a yield of 38.5 IU/mL, that is five times that of the original strain, was achieved by nine successive implantations under the conditions of 10 keV and 30–40 (×2.6?×?10¹³) ions/cm². This optimization further increased the yield of the mutant by 42 %, i.e. 53.6 U/mL which occurred in the mutant cultivated in the optimal fermentation culture medium composed of: rice flour 5 %; ammonium sulfate 1 %; tannic acid 2 %; calcium carbonate 0.5 %; manganese sulfate 0.1 %; and dipotassium phosphate 0.3 %; incubated at 30°C and 180 rpm for 72 h.     

Progression of seasonal activities of adults of the spotted lanternfly,Lycorma delicatula,during the 2017 season of mass flight dispersal behavior in eastern Pennsylvania

During the summer and fall of 2017 in northeastern Pennsylvania we studied the progression of adult behaviors of the spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae) when there was an upsurge in adult flight behavior that was not known to have occurred in 2015 or 2016, the first years following its initial detection in Pennsylvania in late 2014. Sex ratios on A. altissima trunks and branches were routinely ca. 50:50 male:female throughout the 2017 season except in two instances in two of the earliest samplings in which >60% were males. Within the first week after adult eclosion in 2017, in conjunction with extensive feeding-related behaviors on Ailanthus altissima tree trunks, short flights occurred indiscriminately from the foliage of one tree to another or between bushes, trees and vines. One week later these flights became more prevalent and lengthier. Adults of both sexes launched themselves into the wind from non-host trees or from porches, posts and other human-made structures to engage in level or gradually descending straight-line flight trajectories that allowed them to traverse only usually 10 to 40 m of ground in one episode. After the peak of flight dispersal had occurred, the first mating pairs were observed on September 25. All of the 21 pairs of adults we observed in copula exhibited swollen, yellow abdomens in contrast to the thinner, predominantly black abdomens of the adults we had sampled during the earlier feeding and flight phases. Copulating pairs were observed to remain coupled for 2 to 4 h.