Nutrient requirements and stress response of Populus simonii and Paulownia tomentosa

The aim of this investigation was to estimate the optimum nutrient requirements and responses to low relative nutrient addition rates of seedlings of two important broadleaf tree species in China, Populus simonii Carr. and Paulownia tomentosa (Thunb.) Steud. In preliminary experiments the optimum nutrient proportions were estimated under high concentration conditions. The nutrients consumed were replaced by means of daily additions determined by pH and conductivity titrations without changing the nutrient solutions. A relatively high K level was needed in relation to nitrogen; higher than in birch or grey alder seedlings. To obtain a high relative growth rate, suitable proportions by weight were 100 N:70 K:14 P:7 Ca:7 Mg for the Populus seedlings and 100 N:75 K:20 P:8 Ca:9 Mg for the Paulownia seedlings.
In studies of nutrient stress responses the relative nutrient addition rate was used as the treatment variable under low conductivity conditions. The responses and relationships were similar to those described for birch, grey alder and Salix . The relative addition rate, and there was also a strong linear regression between relative growth rate and nitrogen status. Relative growth rates were high and the maximum weight increase was about 19% day⁻¹ in Populus and over 25% day⁻¹ in Paulownia . The nitrogen productivity of Paulownia was very high, 0.26 g dry weight (g N)⁻¹ h⁻¹, and for Populus it was 0.16 g dry weight (g N)⁻¹ h⁻¹.     

甘肃裕固族体质特征初步研究

本文调查了甘肃省裕固族成年人409人(男210人,女199人)的体质特征。其中活体测量51项,活体观察8项。结果表明:裕固族既具有黄种人的特征,也有本民族的特点,例如头部较圆较高;面部较长偏狭;鼻子高;鼻梁直,属狭鼻型;身材普遍较高,体质较好。这些特征与华北地区的汉族和达斡尔族,羌族及锡伯族的特征比较接近,而与苗族、黎族较远。     

少年游泳运动员冬训期间HbA_2百分含量的规律性变化

 本研究用聚丙烯酰胺凝胶垂直板电泳,双波长扫描仪对少年游泳运动员的HbA_2百分含量进行测定。发现大运动量训练对HbA_2水平是有影响的。经六天训练(星期二、五为大运动量训练),星期日休息一天,次周的星期一晨HbA_2百分含量升高,星期二大运动量训练后的次日晨HbA_2百分含量显著下降。运动性贫血的运动员,其HbA_2百分含量一周中的变化趋势与正常运动员相似,但HbA_2百分含量比正常运动员高。     

油菜饼的黄酮成分研究

从油茶饼正丁醇提取物中分离到两个黄酮甙,经UV、~1H NMR、~(13)C NMR、EI-MS、FAB-MS等仪器分析,鉴定为山奈酚-3-O-葡萄吡喃糖基(6→1)鼠李吡喃糖甙(1)和山奈酚-3-O-葡萄吡喃糖基-[(2→1)葡萄吡喃糖基](6→1)鼠李吡喃糖甙(2)。正丁醇提取物以酸水解亦分离到山奈酚(4)。油茶饼正丁醇提取物中还分离到蔗糖,得率达2.3％。     

Immunohistochemical localization of neuropeptide Y in the guinea pig medulla oblongata

Summary The immunohistochemical localization of neuropeptide Y (NPY) was correlated with those of dopamine--hydroxylase (DBH) and vasoactive intestinal polypeptide (VIP) by mapping serial 7 m paraffin sections at three levels of the guina pig lower brainstem: a) area postrema, b) dorsal motor nucleus of the vagus, and c) nucleus prepositus of the hypoglossal nerve. Based on differences in transmitter expression, three populations of NPY-immunoreactive (IR) neurons were distinguished: NPY-IR catecholaminergic cells (NPY/CA), NPY-IR VIP-ergic cells (NPY/VIP), and NPY-IR cells which were not reactive to either DBH or VIP. Within these populations, size differences among neurons in characteristic locations allowed differentiation among the following subpopulations: NPY/CA neurons in the lateral reticular nucleus — magnocellular part (mean neuronal size 538 m²) and parvocellular part (318 m²)-, in the vagus-solitarius complex (433 m²), and in the dorsal strip (348 m²); NPY/VIP neurons in the vagus-solitarius complex (368 m²) and in the nucleus ovalis (236 m²). Apart from scattered NPY-IR cell bodies in the regions listed above, NPY-IR cell bodies in the lateral portion of the nucleus solitarius and in the caudal part of the spinal nucleus of the trigeminal nerve did not exhibit IR to either DBH or VIP. NPY-IR neurons in the area postrema occurred too infrequently for co-localization studies. The differential distribution of heterogeneous NPY-IR cell subpopulations may reflect the involvement of NPY in a variety of neuronal functions.Supported by the Deutsche Forschungsgemeinschaft, grant He 919/6-1     

宁夏同心中新世铲齿象化石

本文记述了宁夏同心地区中中新世哺乳动物群中铲齿象化石——同心铲齿象 (Platybelodon tongxinensis) (原定为同心嵌齿象 (Gomphotherium tongxinensis). 通过与国内外已现的有关铲齿象对比,确认其与国内已发现的葛氏种关系最近,可能属同一枝系.同心种与葛氏种相比,是性质相对原始分布层位较低的我国第二个铲齿象种.文章初步讨论了其 M_3 的某些变异性状.并结合现有的其它标本初步阐述了铲齿象类下门齿的两种结构类型,原始型的同心层状结构和衍生型的齿质柱状结构.建议根据这两种结构仍将铲齿象类划分为 Platybelodontinae 和 Amebelodontinae.     

牛生长激素结构不均一性的研究

本文报导用常规方法分离纯化的牛生长激素,在还原性SDS-11％聚丙烯酰胺凝胶电泳中呈分子量很接近的两条主带(22KD,21.5KD)。用单克隆抗体和多克隆抗体亲和层析技术分析了不同分子量形式的牛生长激素的转化,结果表明:牛生长激素可能在pH5.5条件下转化为21.5KD分子,在pH8.3条件下则转化18KD分子。这几种形式的牛生长激素均保留与抗体的结合力,但亲和力不尽相同,如在亲和层析的洗脱性质上存在差异。已检验分离并部分纯化了18KD分子以备作进一步的研究。     

竹红菌甲素敏化嘌呤和嘧啶碱的光氧化作用及其影响因素

本工作利用光吸收和高效液相色谱(HPLC)技术研究了甲素对DNA分子中四种碱基A、G、C和T光氧化的敏化作用,发现在反应体系的pH为9.0、甲素浓度为3×10~(-5)mol/L、光照40分钟时,G和T紫外吸收明显降低;HPLC分析发现甲素敏化的G光氧化体系比对照体系多出现一组分峰(滞留时间0.927分钟),该峰用475nm波长检测比260nm波长检测灵敏。根据反应机制推测是G环破裂产物。在反应条件固定时,甲素敏化G的光氧化作用受pH、光照时间及甲素浓度影响极大。单线态氧淬灭剂——叠氮钠浓度在40—110mmol/L可部分抑制甲素敏化G的光氧化作用,>110mmol/L时反应完全被阻断,提示甲素对G光氧化的敏化作用主要通过单线态氧(~1O_2)即Ⅱ型机制起作用。本文还讨论了G光氧化的可能途径。     

倭竹属地理分布的研究

倭竹属Shibataea Makino隶于禾本科之竹亚科,现已知有8种,分布于我国东南部的浙江、福建、江苏、安徽、江西等省,广东、台湾两省有少量栽培,日本产1种。苏联、西德、印尼等国所栽培的倭竹均系自我国或日本引入。我国浙-闽地区产8种,且都有野生发现,是本属的现代分布中心。倭竹属植物体型矮小,常植于庭院或公园中供观赏。近年来盆景艺术迅速发展,微型园林日益兴起,倭竹属植物体态优美,常绿,耐寒且易于栽培,为广大园林工作者所垂青。     

高胆固醇高脂肪膳食对家兔β-VLDL组成及其与巨噬细胞相互作用的影响的初步研究

给家兔喂以1％胆固醇及10％菜油(A组)或猪油(B组)50多天后A组血胆固醇水平(824.2±265.1mg/dl)明显低于B组(1666±693.8mg/dl);A组甘油三酯水平(51.9±19.1mg/dl)亦低于B组(104±40.2mg/dl)。二组家兔的β—VLDL的脂类组成无差别,但A组β—VLDL的apoE高于B组,分别为45.2％及37.5％。高分子量apoB(apoB_h)为33.6％,低于B组β-VLDL(47.3％)。A组β-VLDL促进小鼠腹腔巨噬细胞胆固醇堆积的程度大于B组,可能与apoE含量高有关。我们认为多不饱和脂酸减轻动脉粥样硬化(As)的作用不在于改变脂蛋白构成后阻碍泡沫细胞的形成而是促进β—VLDL从体内清除。