89 resultados para Loneliness and isolation


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直到九十年代,以利用拟南芥菜和金鱼草突变体克隆到花器官发育基因为重要标志的植物发育研究取得了重大突破。但由于开花决定过程分子控制机理研究进展却较为缓慢。以mRNA人手利用差异筛选技术获得春化相关基因克隆(verc203,verc17),Northem blot初步证明这些克隆对春化处理的特异性。根据反义RNA理论和技术对克隆化verc203基因功能进行研究。另外,从纯化蛋白人手,在金针菇中克隆到新的溶血性毒蛋白编码基因,并在细菌中得到表达,这一实验为利用此途径来克隆发育调控蛋白的编码基因进行了有益的技术路线探索。本研究的具体结果如下: 1. 春化相关基因(verc203)对冬小麦花发育调控 根据反义RNA的理论和技术进一步证明verc203在冬小麦开花启动和花发育过程中的可能控制作用。将verc203 DNA序列插入带有CaMV35S启动子和GUS基因的pBI221表达载体, 使之能在植物中高效表达反义RNA,并以转正义基因植株作为对照。通过花粉管途径转基因方法,得到326粒反义质粒冬小麦转化种子和1 98粒正义质粒冬小麦转化种子.所有转化处理种子和正常小麦种子萌发后,经春化处理,与未春化冬小麦植株一起培养直到对照植株达到成熟期。实验观察发现,转反义基因植株的抽穗受到明显的阻抑,开花过程大大推迟。其中表达较强的6株转基因植株甚至晚花五十多天。还发现一些表达较弱的植株尽管晚花20到30天,但花器官发育却受到影响,如,雄蕊缺失,穗发育异常等。Southemblot和PCR实验结果表明外源基因整合到转基因植株基因组。 Northrenblot以及报告基因(GUS)活性等实验证明反义基因在转反义基因植株RNA水平上得到高效表达。同时,GUS基因在蛋白质水平上得到表达。基于上述实验,有理由认为ver203基因可能是控制冬小麦春化诱导的成花启动和花发育过程中的主要基因之一。 2. 金针菇毒蛋白flammutoxin编码基因的克隆及其在细菌中的表达 利用色谱分离技术及SDS.PAGE电泳技术从金针菇(Flammuleina velutips)分离得到一种分子量为31 kDa、对人血红细胞具有溶血活性的蛋白质(flammutoxin),通过蛋白质序列微量分析技术测得其N-端3 1个氨基酸顺序。利用氨基酸序列推测其编码基因序列信息,通过RT - PCR克隆到一个由973个核苷酸组成的编码基因,5’端93个核苷酸编码肽链序列与测得flammutoxin N-端氨基酸序列完全相同。基因序列同源性分析表明在GenBank (USA),EMBL Database (Europe)和DDBJ (Japan)基因序列数据库中未找到与之同源的基因序列。这个基因与载体p-半乳糖苷酶部分基因编码的融合蛋白在E coli细胞中有效地得到表达。表达产物的SDS-PAGE,Western blot和溶血活性实验表明它是flammutoxin蛋白原编码基因。并对融合蛋白的溶血活性降低原因作了讨论。

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The phylogenetic relationships within the genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae) remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this genus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that (1) the genus Takifugu is a monophyletic assemblage; (2) the genus is divided into 6 subgroups based on the molecular data; and (3) there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our results also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.

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In this paper we proposed a single ridge waveguide electroabsorption modulated distributed feedback laser (EML) for long-haul high-speed optical fiber communication system. This EML was successfully fabricated by two step metal organic vapor phase epitaxy (MOVPE) including selective area growth (SAG) and helium partially implantation. No obvious changes of the threshold current (< 0.2 mA), extinction ratio (< 0.1 dB), output power (< 0.2 dBm) and isolation resistance were achieved in the preliminary aging test. With 2.5 Gb/s NRZ modulation, no power penalty was observed after the optical signal was transmitted through 280 Km normal single mode fiber.

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本文通过传统和现代微生物生态学方法,从土壤微生物数量、土壤底物诱导呼吸强度和微生物群落多样性角度,评价了长期污灌所致PAHs污染对土壤微生物特征的影响。结果发现沈抚灌区农田PAHs总量在表层为612.3-6362.81μg•kg-1干土,在亚表层为319.5-4318.51μg•kg-1干土。土壤微生物主要类群、功能群数量、微生物生物量碳和代谢商与土壤PAHs污染程度无明显相关性,土壤底物诱导呼吸强度和所试土壤酶与PAHs含量呈显著正相关,微生物商与PAHs含量呈显著负相关,可以作为土壤PAHs污染评价的敏感生化指标之一。污染稻田土壤细菌群落中优势菌群为β-和γ-变形细菌亚纲的成员,中度PAHs土壤的分支杆菌多样性指数较重度和轻度的略高,PAHs污染使一种或几种分支杆菌得到富集。长期污水灌溉造成土壤固氮细菌种群多样性降低,清水灌溉一段时间后,固氮细菌种群结构得到不同程度的恢复,但是,即使清灌不能使其种群结构得到完全恢复。 通过富集得到一株高效降解芘的细菌N12,经鉴定确认为分支杆菌。经10天培养菌株可将100mg•l-1芘降解97.84%。还可降解菲、苊、芴,不能降解萘、蒽和苯并[a]芘。污染土壤修复实验表明,单一接种菌剂对芘的降解率为57.42%,含N12的混合接种菌剂对芘的降解率为61.11%。

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本研究分为三个部分:1.以坛紫菜(Porphyra haitanesis Chang et Zheng)的叶状体和丝状体为研究对象,比较坛紫菜叶状体和丝状体的光合色素、色素蛋白的组成,并提取纯化藻红蛋白、藻蓝蛋白、藻胆体及类囊体膜和光系统。研究结果表明坛紫菜叶状体和丝状体色素及色素蛋白的含量不同,藻红蛋白是主要的色素蛋白,坛紫菜叶状体和丝状体的藻红蛋白的含量分别为2.9mg藻红蛋白/g鲜重、4.2mg藻红蛋白/g鲜重,这表明坛紫菜叶状体和丝状体藻红蛋白含量丰富,是提取藻红蛋白很好的材料。藻胆体的性质差异不大,但类囊体膜差异显著,从坛紫菜叶状体中分离到了两种不同的类囊体膜带,光系统Ⅰ(PSⅠ)和PSⅡ分别结合在两条类囊体膜带上,但从坛紫菜丝状体中也分离到两条类囊体膜带,它们的光谱性质和蛋白组成相似,仅放氧速率和DCIP活性有差异,从坛紫菜丝状体中我们仅分离到PSⅡ。坛紫菜叶状体PSⅡ有5种外在蛋白(33、20、Cytc 550、15、12kDa蛋白),而坛紫菜丝状体外在蛋白仅有4条,缺少12kDa蛋白。2. 以在中国江苏部分地区进行了大规模的商业化栽培的突变体条斑紫菜(Porphyra yezoensis Ueda)和野生型条斑紫菜为研究对象,比较其色素及色素蛋白组成、对不能光质的利用率及藻胆体的组成。条斑紫菜和突变型条斑紫菜对不同的光质利用效果有差异,在白光的照射下,野生型紫菜的放氧速率最大,而突变型紫菜在黄光照射下的放氧速率最大。条斑紫菜野生型与突变型色素含量上有明显的差异,突变型紫菜的藻红蛋白含量明显减少而藻蓝蛋白的含量增加。通过杂交的方法证实诱变所获得条斑紫菜突变体为细胞质突变,但是突变型紫菜却发生了由细胞核编码的γ亚基的缺失,这表明突变型紫菜藻红蛋白含量和性质发生了明显的变化。3. 为了找出淡水红藻-深紫美芒藻(Compsopogon coeruleus (Balbis) Montagne)分布狭窄及生物产量低的原因,本文对深紫美芒藻在不同的盐离子浓度下的放氧速率及藻胆体色素组成和结构上进行研究。结果显示:微量的NaCl(0.1mM)促进深紫美芒藻放氧,而深紫美芒藻在较高的NaCl(1、10mM), NaH2PO4 (0.1、1、10mM)和 NH4NO3(0.1、1、10mM)溶液中却没有检测到氧气的产生。这与深紫美芒藻生长的环境一致即深紫美芒藻生活在低盐浓度、低营养的泉水中。深紫美芒藻的藻胆体是由藻红蛋白、藻蓝蛋白及别藻蓝蛋白组成,上面结合α、β和γ亚基,含有藻红胆素、藻篮胆素,但缺乏缺少藻尿胆素。

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Achievement motive is human’s social motive. In some sense, one’s all-life achievements are decided by his/her achievement motive. By which we can conclude that achievement motive has close connection with individual emotional experience. People pursuing success experience more positive emotion and less negative one, and have good behavioral adaptability. This study aims at explore the relation between achievement motive and behavior problems in the secondary vocational education schools through questionaries (the achievement motivation scale, UCLA Loneliness Scale,State-Trait Anxiety Inventory,Center for Epidemiologic Studies depression Scale and middle school students'behavior questionnaire). There were 1005 students whose age ranged from 14to21 years completed the questionnaires. The main conclusions of this thesis are as follows: (1) Achievement motive of student in the secondary vocational education schools is significantly lower than that of students in the senior high school. (2) Students in the secondary vocational education schools show more obvious emotion and Externalizing behavior problems than those of the senior high schools. (3) Students’ motivation for pursuing success in the secondary vocational education schools has negative correlation with emotion and Externalizing behavior problem, while the motivation for avoiding failure has positive correlation with the emotion and Externalizing behavior problem. Achievement motivation has negative correlation with emotion and Externalizing behavior problem. (4) Students’ achievement motivation shows obvious gender difference in the secondary vocational education schools. The avoiding failure element shows upward trend with the grades increasing and the difference is obvious. While the students’ achievement motive in the secondary vocational education schools shows significantly downward trend with the grades increasing. Whether holding a post at school has influence on the students’ achievement motivation, and the difference is significant. (5) Students’ Externalizing behavior problem in the secondary vocational education schools shows obvious gender difference. Whether holding a post at school has influence on the students’ Externalizing behavior problem, and depression and loneliness, and the difference is significant. Key words: Students in the Secondary Vocational Education Schools, Achievement Motivation, Behavior Problem, Emotion Problem, Externalizing Behavior Problem (Note: In this study, the behavior problems include not only the externalizing behavior problems, but also emotion problems.)

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