应用组织芯片技术研究抑癌候选基因NDRG2在淋巴瘤组织中的表达及其意义

目的:应用组织芯片技术分析抑癌候选基因NDRG2在人类淋巴瘤组织、淋巴结正常组织及淋巴结良性病变组织中的表达情况.方法:采用小鼠抗NDRG2单克隆抗体的免疫组织化学ABC法,研究NDRG2在不同淋巴结组织的表达,并分析NDRG2在不同淋巴结组织中的表达差异.结果:免疫组化结果显示,淋巴瘤组织与淋巴结良性病变组织中DNRG2的表达相比呈显著性差异(P<0.05),淋巴瘤组织与正常淋巴结组织中DNRG2的表达相比呈显著性差异(P<0.05).淋巴结良性病变组织与正常淋巴结组织中DNRG2的表达相比呈显著性差异(P<0.05).正常淋巴结,淋巴结良性病变及淋巴瘤组织中NDRG2的阳性表达率分别为92.5%(37/40)、67.5%(27/40)和18.51%(15/81),3者间比较,差异有统计学意义.结论:NDRG2在淋巴瘤组织中呈低表达,提示其可能对淋巴瘤的发生或发展有重要作用,这不仅为研究淋巴瘤的发病机制进一步提供了线索,而且对淋巴瘤的诊断和治疗具有重要意义.     

黑龙江凉水自然保护区苏云金芽孢杆菌的收集与鉴定

估,实验结果表明东北森林地区具有丰富多样的Bt菌株和杀虫基因资源.     

自血光化学疗法对放疗肿瘤患者细胞免疫功能的影响

本文通过对肿瘤患者Ｅ玫瑰花环及淋巴细胞转化率的检测,探讨自血光化学放射敏疗法对机体免疫功能的影响。结果表明：单纯放疗组Ｅ玫瑰花环形成及淋巴细胞转化率较放职前明显下降,而自血光化学放疗增敏组治疗前后上述免疫功能无明显改变,表明自血光化学疗法对肿瘤放疗患者的细胞免疫功能具有保护作用。     

岷江柏天然种群种实表型变异特征

运用巢式方差分析、变异系数、表型分化系数和聚类分析等多种分析方法,研究了11个岷江柏种群的13个种实表型性状在种群内和种群间的变异及其与环境因子间的关系,并对其进行了类群划分.结果表明: 岷江柏种实表型性状在种群间和种群内均存在显著差异,种群内的变异(49.7%)大于种群间的变异(28.6%),种间平均分化系数为43.4%,分化程度相对较大.球果质量的平均变异系数最高(37.2%),其次是单个球果种子质量,球果长的平均变异系数最小(8.0%),是最稳定的种实性状.康定县的表型多样性最丰富,武都县的最小.在岷江柏的研究区内,最热月的平均气温和生长季的水分条件是其种实表型的主要限制因子.依据13个种实表型性状将11个岷江柏天然种群分为2类3亚类,基本上代表了3个流域的种群分布情况.大渡河流域种群种实表型性状最佳,岷江流域最差.     

嗜银细胞在菲牛蛭消化管中的形态与分布特征

运用Grimelius银染法对菲牛蛭(Poecilobdella manillensis)消化管内嗜银细胞的分布和形态进行观察,并根据嗜银细胞的分布特点统计其分布密度。消化管除食道外各部位均有嗜银细胞分布,细胞染棕色或黑色;嗜银细胞基本位于上皮细胞之间和固有层内,主要呈圆形、椭圆形、锥体形和长条形等多种形态;部分细胞胞突明显,细胞内可见黑色分泌颗粒。嗜银细胞分布密度为颚片最高,嗉囊次之,直肠最低,食道内未检测出嗜银细胞。消化管各段嗜银细胞的形态特征和分布规律可能与其食性和消化生理活动密切相关。     

Enhanced thermostability of keratinase by computational design and empirical mutation

Keratinases are proteolytic enzymes capable of degrading insoluble keratins. The importance of these enzymes is being increasingly recognized in fields as diverse as animal feed production, textile processing, detergent formulation, leather manufacture, and medicine. To enhance the thermostability of Bacillus licheniformis BBE11-1 keratinase, the PoPMuSiC algorithm was applied to predict the folding free energy change (ΔΔG) of amino acid substitutions. Use of the algorithm in combination with molecular modification of homologous subtilisin allowed the introduction of four amino acid substitutions (N122Y, N217S, A193P, N160C) into the enzyme by site-directed mutagenesis, and the mutant genes were expressed in Bacillus subtilis WB600. The quadruple mutant displayed synergistic or additive effects with an 8.6-fold increase in the t _1/2 value at 60 °C. The N122Y substitution also led to an approximately 5.6-fold increase in catalytic efficiency compared to that of the wild-type keratinase. These results provide further insight into the thermostability of keratinase and suggest further potential industrial applications.     

Linking thaw depth with soil moisture and plant community composition: effects of permafrost degradation on alpine ecosystems on the Qinghai-Tibet Plateau

Background and aims

The warming of the planet in recent decades has caused rapid, widespread permafrost degradation on the Qinghai–Tibet Plateau. These changes may significantly affect soil moisture content and nutrient supply, thereby affecting ecosystem structure and function. This study aimed to describe the dynamic changes in thaw depth, assess the relationship between thaw depth and soil moisture content, and analyze the changes in species composition and water-use efficiency in response to permafrost degradation.

Methods

We surveyed species composition, thaw depth, ground temperature, soil moisture, nutrient content, and foliar stable carbon isotope compositions to gain insights into the response of alpine grassland ecosystems to permafrost degradation on the Qinghai-Tibet Plateau.

Results

Moisture content of the surface layer decreased with increasing thaw depth. The correlation between thaw depth and surface soil moisture content was strongest in June and decreased in July and August. The strongest correlation occurred at a depth of 20 cm to 30 cm. The dominant species shifted from Cyperaceae in alpine meadow to mesoxerophytes in alpine steppe before finally shifting to xerophytes in alpine desert steppe. Thaw depth correlation was significantly negative with organic C content (r?=??0.49, P?<?0.05) and with total N content (r?=??0.62, P?<?0.01). The leaf δ¹³C of Carex moorcroftii increased with increasing thaw depth and followed a linear relationship (R ²?=?0.85, P?=?0.008).

Conclusions

Permafrost degradation decreases surface soil moisture and soil nutrient supply capacity. Increasing permafrost degradation decreases the number of plant families and species, with hygrophytes and mesophytes gradually replaced by mesoxerophytes and xerophytes. The water-use efficiency of plants improved in response to increasing water stress as surface layers dried during permafrost degradation. Permafrost on the Qinghai–Tibetan Plateau is expected to further degrade as global warming worsens. Therefore, more attention should be dedicated to the response of alpine ecosystems during permafrost degradation.     

菜豆花粉发育中质体和线粒体及其DNA存在的状况——着重阐明质体遗传的细胞学基础

应用电镜和DNA的DAPI荧光检测技术研究了菜豆(Phaseolus vulgaris L.)小孢子/花粉发育中质体和线粒体及其DNA存在的状况。观察表明:在小孢子分裂时质体全部分配到营养细胞中,初形成的生殖细胞已不含质体。线粒体和质体的DNA在花粉发育中也先后降解,生殖细胞从刚形成时发育至成熟花粉时期这两种细胞器DNA均不存在。研究结果为菜豆质体母系遗传提供了确切的细胞学证据。遗传分析的研究曾确定菜豆质体为双亲遗传,对与本研究结论不同的原因进行了讨论。     

潜流人工湿地中植物对氮磷净化影响效应的研究

采用潜流人工湿地系统,配制以NH⁺₄-N、NO^-₃-N和PO^3-₄-P为主要成分的模拟污水,通过间歇运行方式,考察了芦苇和小叶章的生长情况、生理生态学特性及其对污水中N、P净化效能的影响,并研究了植物对湿地系统pH变化、NO^-₃-N和NH⁺₄-N净化效率的影响。结果表明,当水力停留时间为7d时,小叶章和芦苇湿地对TN的去除率分别为65.1%和99.6%,去除负荷分别为1.66g · m^-3 · d^-1和2.53g · m^-3 · d^-1。小叶章和芦苇对去除TN的贡献率分别为14.7%、61.7%,对去除TP的贡献率分别为11.7%和12.9%;芦苇植株内N、P浓度分别为29.2mg/g和3.41mg/g。芦苇湿地的净化效能高于小叶章湿地。湿地系统中pH值先升高后降低的拐点可作为氨氧化反应结束的指示参数。     

中国海南岛灵芝资源及其分布特征

本文报道了海南岛的灵芝科真菌７８种,分属于４个属,３个亚属,２个组。分析了灵芝在不同的热带植被类型中,其种类的组成不同。种类多样性变化呈：常绿季雨林＞热带雨林＞低山雨林＞中山雨林＞热带半落叶季雨林＞人工林＞河谷雨林＞稀树草原＞山顶矮林＞红树林的趋势