不同地区望天树种群形态特征的比较

本文比较了间断分布在云南南部、东南部和广西西南部的望天树种群的形态特征,三者的差异主要在果翅上。云南南部的望天树果翅短而宽,广西西南部的果翅长而窄,云南东南部的望天树居中;云南南部的望天树果翅长度在广西望天树的翅长变幅内,翅宽虽超出后者变幅,却在云南东南部的翅宽变幅内。三者在形态特征上有统计学的差异,但变异是连续的,在分类学上区分为三个变种还嫌不足。     

LIMITATIONS OF PHOTOSYNTHESIS IN DIFFERENT REGIONS OF THE ZEA MAYS LEAF

The progressive development of the photosynthetic apparatus occurring along the length of the Zea mays leaf offers a convenient system with which to examine the limitations to photosynthetic CO₂ assimilation during biogenesis of a C₄ leaf. Changes in light-induced O₂ evolution and CO₂ assimilation, chlorophyll content, activity of PEP-carboxylase, NADP-malic enzyme and the 'R5P system' (consisting of d -ribose-5-phosphate-keto isomerase, ATP- d -ribulose-5 phosphate 1-phosphotransferase and d -ribulose-1,5-bisphosphate carboxylase) and fluorescence emission characteristics were examined along the length of the second leaf of 7-day-old plants grown under a diurnal light regime. The results suggest that the major limitation to CO₂ assimilation in the leaf sheath lies within the chlorenchyma and is either energy supply for carboxylation or the capacity of key photosynthetic enzymes. In the leaf blade stomatal resistance to CO₂ diffusion constitutes a major fraction of the total leaf resistance to CO₂ assimilation implicating the stoma as the major limiting factor to photosynthetic CO₂ assimilation.     

家兔Bezold—Jarisch反射时区域性交感神经传出放电的变化

在46只麻醉兔,记录了经冠脉内注射尼古丁诱发Bezold-Jarisch反射时不同区域交感神经传出放电的变化。肾神经、心脏神经、脾神经、星状神经节-颈神经交通支和颈前神经节的颈外动脉支五个部位的交感性传出放电,在冠脉内注射尼古丁后均减少,其中以肾神经、心脏神经和脾神经的减少更为显著。此结果表明,交感神经传出放电减少所致的总外周阻力降低,在Bezold-Jarisch反射诱发的低血压中起着重要作用。     

我国不同地区东亚钳蝎(Buthus martensii Karsch)毒在三种类型电泳中的比较研究

用SDS—不连续聚丙烯酰胺凝胶板电泳、pH4.5—不连续聚丙烯酰胺凝胶板电泳和聚丙烯酰胺凝胶圆盘等电聚焦电泳,分离我国不同地区东亚钳蝎毒。其图谱表明:不同产地的东亚钳蝎毒蛋白的种类及含量存在一定的差异,地区相近,差异较小,反之亦然。     

不同地域宁夏枸杞活性成分的研究

对不同地域宁夏枸杞中活性成分的含量进行了分析。研究结果显示产地不同的宁夏枸杞中活性成分含量有明显差别,宁夏银川产的宁夏枸杞中所含的活性成分高于辽宁朝阳产的宁夏枸杞;在积温高、土壤呈弱碱性条件下,宁夏枸杞中的多糖、游离氨基酸、果红素含量较高。     

不同海拔地区紫外线B辐射状况及植物叶片紫外线吸收物质含量的分析

对不同海拔地区的太阳 UV- B辐射和植物叶片的光学特性进行了比较研究。结果表明 :位于高海拔地区的海北高寒草甸生态系统定位站 ,太阳 UV- B辐射明显高于相近纬度的西宁、兰州和南京地区。UV- B辐射与总辐射和 PAR的日变化规律相似 ,都受太阳高度角的直接影响 ,在当地太阳正午时最高。UV- B/Q的日变化也为单峰曲线 ,海北站地区的 UV- B/Q高于西宁的同期测定结果。对珠芽蓼等植物的研究表明 ,生长于海北站地区的珠芽蓼 ,其叶片中紫外线吸收物质的含量明显高于西宁的同种植物 ,也略高于海拔较高的达坂山和小达坂山山顶的同种植物。叶绿素含量以海北站珠芽蓼最低 ,达坂山和小达坂山的同种植物最高。珠芽蓼叶片中类胡萝卜素的含量以西宁最低 ,海北站、达坂山和小达坂山依次升高。海北站矮嵩草与从海北站移植到西宁生长 4年的同种植物相比 ,叶片中紫外线吸收物质、叶绿素、类胡萝卜素的变化与生长于两地区的珠芽蓼相同     

BIOCHEMICAL COMPOSITION OF DIFFERENT REGIONS IN BRAINS OF SMALL-FOR-DATE INFANTS

Different regions of the brains of babies born with low birth weights for the gestational age (small-for-date infants) were analysed for various chemical constituents. The brains of small-for-date babies were reduced in size. On a percentage basis, cerebellum and medulla oblongata were more affected than cerebrum. Cellularity, estimated by DNA content, was affected only in the cerebrum. However, the cell size and the concentrations of various constituents (proteins, lipids, different classes of lipids) studied in different regions of the brains of small-for-date infants remained unaffected compared to those found in the normal brains.     

COMPARISON OF THE OSMOTIC VOLUME CHANGES IN CHLOROPLASTS ISOLATED FROM DIFFERENT PLANTS

Chloroplasts were isolated from leaves of four plant species(spinach, New. Zealand spinach, Swiss Chard and tomato) andtheir osmotic behaviour was compared. Maximal contraction ofchloroplasts from all plant sources occurred at 0.3–0.4M sucrose. The volume of the particles at this sucrose concentrationwas also similar in all cases; 300 mm³ per 10¹⁰ chloroplasts.At higher and lower sucrose concentrations, the chloroplastsswell. The degree of swelling, especially in higher sucroseconcentrations, differed in chloroplasts from different sources.Tomato chloroplasts are most sensitive, and the spinach chloroplastsare the most resistant to all types of treatment. Tomato chloroplastsrequire rather high phosphate concentrations for good preservation. Changes in optical density at 520 mµ can be used to geta rough idea about the condition of the particles. (Received February 7, 1966; )     

不同消化方法对测定生物样品中硒含量的比较研究

本文比较了干法消化、普通湿法消化、高压消化、微波消化对测定富含有机硒的生物样品中硒含量的影响.结果显示,高压及微波消化等密闭消化体系具有显著的优点,适合生物样品中富含有机硒的硒含量的测定.     

不同产地三尖杉中三尖杉酯碱和高三尖杉酯碱的含量测定

本文对三尖杉科(属)中的三尖杉Cephalotaxus fortunei Hook f.植物中所含抗白血病的三尖杉酯碱harringtonine与高三尖杉酯碱homoharringtonine作了不同产地和不同部位的含量测定。     

不同品种、不同花期的依兰花精油成分研究

为探讨依兰花精油的香气质量,我们对云南省西双版纳产依兰花精油以及引种栽培于西双版纳的泰国种、老挝种的依兰花精油的化学成分在Finnigan-4510 GC/MS/DS上用毛细管柱进行了定性和定量分析,鉴定了44个化学成分。分析结果表明,依兰油的香气与品种及精油中的酯类、醇类和酚醚的含量有关。倍半萜烯类和倍半萜醇类的含量越高,其香气质量越差。就西双版纳产依兰油的香气而言,依兰花由青转黄时得到的精油远较绿花和花蕾油为好。     

A COMPARISON OF DIFFERENT METHODS OF AGE DETERMINATION IN THE SHARPTOOTH CATFISH CLARIAS GARIEPINUS

SUMMARY

Growth of the sharptooth catfish Clarias gariepinus from four southern African impoundments was estimated by back-calculating age from vertebrae and spines. Length frequency analysis supported the growth estimates derived from vertebrae but not those from spines.- Spines under-estimated the age of fish from all four dams; this discrepancy increased with age. Ring formation occurred in the winter months (April to July) and not at the time of spawning (November to February) or low water levels (August to December).

A critical review of ageing studies shows a lack of consistency in the choice of formula used for back-calculation. The correct choice of formula for age and growth estimates derived from back-calculation must be based upon detailed analysis of fish size versus body part size. Unquestioning acceptance of the Lee equation with its “correction factor” should he avoided.     

莼菜根不同发育区细胞中高尔基体的发育与结构变化

在莼菜根分生区细胞中,部分粗糙内质网片断转化成单个潴泡,游离于细胞基质中的单个潴泡相互叠加后形成具6—8个潴泡组成的高尔基体。高尔基体在伸长区进入分泌高峰期,由于其成熟面的潴泡溢出大量分泌泡后消失或潴泡游离出去,使高尔基体潴泡数目减少,部分高尔基体形成面有内质网溢出的小泡互相融合后形成新的潴泡补充,另一些高尔基体由于得不到潴泡补充而逐渐消失;这可能是成熟区细胞内高尔基体数目减少的重要原因之一。     

不同产地西洋参皂甙成分的HPLC分析

以西洋参的主要皂甙成分人参皂甙Re和Rb1为标准对照品 ,建立西洋参药材的HPLC定量分析技术 ,并参考人参皂甙Rc,Rd及Rg2 的相对峰面积进行主成分分析。色谱条件为 :C18柱 (5 μm ,3.9× 15 0mm) ,乙腈 :水流动相 ,二元梯度洗脱 ,检测波长 2 0 3nm。结果表明 ,就皂甙成分的组成与含量而言通过人参皂甙Re和Rb1的含量测定和皂甙的主成分分析 ,不同产地的西洋参药材皂甙成分存在一定的差别。吉林省靖宇县产的西洋参与进口品最为接近。     

不同方法纯化体外培养脊髓神经元的比较

研究和比较三种不同纯化神经元的方法,以便提供一种纯化效率较高的纯化技术,神经细胞取自于胚胎12－14天小鼠脊髓,应用药物法、差速贴壁法、磁珠包被抗体反应法对神经元进行纯化,然后用NSE免疫组化反应和NSE－ELISA法比较三种不同纯化方法在不同培养时间24、36、48、60、72、84hrs得以神经元的纯度和显示其数目的OD值。结果发现,磁珠包被抗体反应法神经元的纯度随着培养时间的延长纯度可达95％以上,而差速贴壁法所得神经元在培养24hrs后呈现下降趋势,72hrs后可达60％,药物法则阳性神经元比较稳定,但纯度较低,一旦停药,则呈现下降趋势84hrs后达到56％左右。     

A COMPARISON OF THE HETEROGENEOUS NUCLEAR RNA OF HELA CELLS IN DIFFERENT PERIODS OF THE CELL GROWTH CYCLE

HeLa cells synthesize heterogeneous nuclear RNA (HnRNA) in the G₁, S, and G₂ portions of the cell cycle. HnRNA prepared from these various periods was compared by RNA-DNA hybridization experiments. The results indicated that some of the HnRNA molecules were equivalent at all times in the cell cycle, but limitations in the sensitivity of the hydridization reactions, as well as in the spectrum of hybridizing molecules, restrict the conclusions that can be drawn from these comparisons.