Factors determining Petal Colour of Baccara Roses I: THE CONTRIBUTION OF EPIDERMIS AND MESOPHYLL

The partition of light radiated on to the outer epidermis ofa Baccara rose petal or on to an intact petal was examined.Most of the red light was either reflected or transmitted whereasother wavelengths and especially the green range were absorbed.When the total amount of light transmitted (epidermis) or reflected(intact petal) increased, a rise in the blue range was recordedand the colour of the petal, determined objectively by CIE orMunsell's method, became more purple. Examination of the partition of light in the different layersof the petal revealed that light reflected from the outer epidermisis made up of two parts; one part is reflected directly andthe other part is first transmitted through the epidermis, reachesthe mesophyll, is reflected from it and is then transmittedthrough the epidermis. This latter part causes a shift in colourfrom purple to red. Colour differences between different petals on one flower anddifferent parts of the same petal were defined objectively.The change from red to purple colour was connected with vigorousgrowth of either the petal or epidermal cells, respectively. The contribution of the mesophyll in changing the reflectancecurve of petals is explained and it is suggested that althoughthe mesophyll is colourless, it contributes to a great extentto the changes occurring in petal colour.     

Factors Determining Petal Colour of Baccara Roses II: THE EFFECT OF PIGMENT CONCENTRATION

‘Blueing’ in young and senescing petals was comparedin the red rose cv. Baccara. The ‘blueing’ of senescingflowers is accompanied by a bathochromic shift in the lightreflectance curve, a rise in the pH value and a decrease inthe malic acid concentration of the petal tissue. These factorsindicate that a complex with a co-pigment is produced. Similarchanges were not found in the ‘blueing’ of youngflowers, where a decrease was found in pigment concentrationper unit weight as well as per unit area of petal. A similar‘blueing’ was achieved by diluting a solution ofcrystalline cyanin. The phenomenon of ‘blueing’by dilution is discussed in the light of Bougeur's law.     

不同森林群落结构与光能利用率的关系

本文在人工落叶松纯林及人工落叶松与水典柳混交林的林冠观测数据的基础上建立了落叶松松和水曲柳的树冠锥体模型。通过对上述两种森林群落结构的太阳辐射的观测,利用电磁波的吸收,反射和透射理论分别对以上两种森林群落的光能利用率进行了计算。结果表明理论计算值与实测结果基本一致;双层次混交林的光能利用率高于单层纯林的光能利用率。     

肝癌细胞整合素受-配体比与其粘附稳定性的相关性实验研究

整合素与其胞外基质配体间的相互作用对调节细胞的粘附和运动起着重要的作用.肝癌细胞的胞外基质减少,而整合素β1的表达却增高,其比例失衡影响肝癌细胞的粘附与运动行为.作者通过细胞形态学观察、图像分析,微管吸吮和流式细胞仪等手段,对肝癌细胞、正常肝细胞的整合素表达水平、裱衬Fn前后肝癌细胞的运动能力及粘附力进行检测和定量分析,发现肝癌细胞的整合素表达量高于正常肝细胞;肝癌细胞粘附力较正常肝细胞低,迁移速度增快,补充适当浓度胞外配体Fn可使胞外受配体比例恢复到正常肝细胞的整合素表达水平,裱衬Fn后肝癌细胞的粘附力增强,细胞运动能力减弱.这些结果说明胞外配体Fn对肝癌细胞整合素表达有下调作用,肝癌细胞的受.配体比例是影响其粘附和运动的因素之一.     

THE Si:C:N RATIO OF MARINE DIATOMS: INTERSPECIFIC VARIABILITY AND THE EFFECT OF SOME ENVIRONMENTAL VARIABLES1

The variability of marine diatom Si:C and Si:N composition ratios was examined to assess their utility as ecological conversion factors. Twenty-seven diatom species grown under an 18:6 h LD cycle and sampled at the end of the light period gave mean ratios, by atoms, of 0.13 ± 0.04 and 1.12 ± 0.33 for Si:C and Si:N ratios, respectively (95% C.I. reported). The mean ratios for 18 species grown under continuous illumination were 0.12 ± 0.03 for Si:C and 0.95 ± 0.23 for Si:N. The mean ratios of the clones grown under constant light were not statistically different from those calculated for the same species grown under an 18:6 h LD photoperiod. The overall mean Si:C and Si:N ratios for the 18:6 h LD and continuous light experiments taken together, weighted by the number of species in each experiment, are 0.13 and 1.05, respectively. The average ratios for the nine nanoplankton species (<20 μm) examined were 0.09 ± 0.03 for Si:C and 0.80 ± 0.35 for Si:N. The eighteen netplankton species (>20 μm) had higher mean ratios, Si:C = 0.15 ± 0.04 and Si:N = 1.20 ± 0.37. Time course sampling throughout a 24 h period revealed twofold variations in both ratios for individual species grown on a 14:10 h LD cycle. Changes in irradiance can also produce factor of two variations, both ratios being higher under low light. Comparisons of these data with those from the literature regarding the effects of temperature and nutrient limitation on diatom elemental composition suggest that use of these ratios to convert field estimates of biogenic silica into nitrogen or carbon units, or to estimate silica production from ¹⁴C data, should yield results accurate to within a factor of three under most circumstances.     

蝎毒抗癫痫作用与微生态调节剂的关系

:一次颈部皮下给予海人酸 (Kainic acid,KA ,10 m g/ kg)诱发 SD大鼠出现急性癫痫发作后 ,将实验组动物随机分为 3组 ,每天灌胃分别给予生理盐水、微生态调节剂 [活菌数 4× 10 9个 (0 .4ml)只 ]和蝎毒粗提液 (SV,10 0 mg/ kg)。 10天后再次给予同样剂量的 KA检测癫痫敏感性 ,行为结果经统计学处理后表明 ,两者均可明显抑制动物癫痫敏感性的形成。免疫组化结果表明 ,两者均可防止海马硬化的形成。本工作进一步探讨了微生态调节剂与蝎毒抗癫痫作用的关系     

激动素对韭菜叶片衰老的影响与活性氧代谢的关系

本文研究了激动素对韭菜离体叶片衰老的影响与活性氧代谢的关系。结果表明,在暗诱导衰老过程中抗坏血酸、谷胱甘肽含量和超氧物岐化酶、过氧化氢酶活性均呈下降趋势。激动素在延缓衰老的同时,明显抑制了抗坏血酸、谷胱甘肽含量和超氧物岐化酶、过氧化氢酶活性的下降以及膜脂过氧化产物丙二醛的积累。证明激动素延缓衰老的作用是通过调节活性氧代谢来实现的。     

GM3对重建Gs与AC偶联功能的影响

将神经节苷脂ＧＭ３（Ｍｏｎｏｓｉａｌｏｇａｎｇｌｉｏｓｉｄｅ－ＧＭ３）通过保温法掺入到含激活型Ｇ蛋白（ＳｔｉｍｕｌａｔｏｒｙＧＴＰ－ｂｉｎｄｉｎｇｐｒｏｔｅｉｎ,Ｇｓ）与腺苷酸环化酶（ＡｄｅｎｙｌｙｌＣｙｃｌａｓｅ,ＡＣ）的脂酶体中,研究了ＧＭ３对Ｇｓ和ＡＣ偶联功能的影响。实验结果表明,在４－１０μｍｏｌ／Ｌ浓度范围的ＧＭ３增加ＡＣ的基础活力;在高于４μｍｏｌ／Ｌ时,ＧＭ３可显著抑制Ｇｓ激活ＡＣ的能力;而在ＧＭ３浓度高于１００μｍｏｌ／Ｌ的条件下,Ｇｓ结合ＧＴＰγＳ（Ｇｕａｎｏｓｉｎｅ５＇－Ｏ－（３－ｔｈｉｏｔｒｉｐｈｏｓｐｈａｔｅ））的活力受到明显抑制。随外源ＧＭ３浓度的增加,ＧＭ３对Ｇｓ激活ＡＣ的能力与对ＡＣ基础活力的影响似乎并不完全一致。这些结果提示,Ｇｓ与ＡＣ的解偶联对较低浓度的ＧＭ３的影响更加敏感。用荧光探剂ＭＣ５４０标记脂酶体,测量其荧光光谱的结果显示,随着ＧＭ３浓度增加,ＭＣ５４０的荧光强度增强,这说明外源性的ＧＭ３的掺入使膜脂质分子头部的堆积变得更加疏松。这可能提示,ＧＭ３介导的膜脂物理状态的变化是调节Ｇｓ与ＡＣ偶联功能的重要因素之一。     

东茛菪碱抗吗啡依赖作用与海马细胞内钙的关系

目的观察东莨菪碱(scopolamin,Sco)对吗啡(morphine,Mor)致小鼠依赖性作用的影响及其机制分析.方法连续7 d腹腔内注射吗啡建立吗啡依赖小鼠模型;热板法测定痛阈;纳络酮(naloxone,Nal)催促实验计数小鼠跳跃次数和跳跃动物率;流式细胞术测量海马细胞内游离Ca2+([Ca2+]i)浓度.结果吗啡依赖小鼠的痛阈明显下降,跳跃次数和跳跃动物率明显增加,海马[Ca2+]i明显增加.给予东莨菪碱(4mg·kg-1×7 d)后,吗啡依赖小鼠海马[Ca2+]i明显减少(P＜0.05),痛阈提高(P＜0.01),跳跃次数和跳跃动物率减少(P＜0.05).结论东莨菪碱具有对抗吗啡依赖性的作用,其机制可能与降低脑细胞内游离Ca2+水平有关.     

东莨菪碱抗吗啡依赖作用与海马细胞内钙的关系

目的:观察东莨菪碱(scopolamin,Sco)对吗啡(morphine,Mor)致小鼠依赖性作用的影响及其机制分析。方法:连续7 d腹腔内注射吗啡建立吗啡依赖小鼠模型;热板法测定痛阈;纳络酮(naloxone,Nal)催促实验计数小鼠跳跃次数和跳跃动物率;流式细胞术测量海马细胞内游离Ca2 ([Ca2 ]i)浓度。结果:吗啡依赖小鼠的痛阈明显下降,跳跃次数和跳跃动物率明显增加,海马[Ca2 ]i明显增加。给予东莨菪碱(4mg.kg-1×7 d)后,吗啡依赖小鼠海马[Ca2 ]i明显减少(P<0.05),痛阈提高(P<0.01),跳跃次数和跳跃动物率减少(P<0.05)。结论:东莨菪碱具有对抗吗啡依赖性的作用,其机制可能与降低脑细胞内游离Ca2 水平有关。     

PHOTOCHEMISTRY OF VISUAL PURPLE : III. THE RELATION BETWEEN THE INTENSITY OF LIGHT AND THE RATE OF BLEACHING OF VISUAL PURPLE.

It is shown that the velocity of bleaching of visual purple by light, under comparable conditions of concentration, volume, and surface exposed, is directly proportional to the intensity.     

SEASONAL EFFECT ON THE RELATIONSHIP BETWEEN THE PHOTOSYNTHETIC CAPACITY OF INTERTIDAL MICROPHYTOBENTHOS AND TEMPERATURE1

The response of the photosynthetic capacity (P_max) of microphytobenthos to short-term variations of temperature (in the range 5–35° C) was assessed on a seasonal basis. The relationship is described mathematically, and relevant physiological parameters are identified: P_MAX, the maximum value of P_max achieved at T_opl, the optimum temperature. Estimated values of T_opt do not change significantly throughout the year and remain close to 25° C. It is thus concluded that T_opt is not influenced by seasonal variations in the daily range of mud surface temperature. Identical conclusions hold for T_max (ca. 38° C), the thermal threshold beyond which no photosynthesis occurs. Conversely, P_MA estimates exhibit substantial variability: P_MAX (mean ± root mean square error) is highest in April (11.18 ± 0.42 [μg C · [μg Chl a]^?1· h^?1) during the beginning of the annual increase in temperature, photoperiod, and maximum irradiance and is lowest in December (3.04 ± 0.16 μg C · [μg Chl a]^?1· h^?l). From an ecological point of view, the short-term and seasonal variations of P_MAX suggest that the microphytobenthic community takes advantage of the abiotic spring environmental conditions, allowing the onset of the bloom. Nevertheless, no “acclimation strategy” (i.e. shifts in T_opt and T_max that prevent temperature inhibition in summer or improve photosynthetic rates in winter) is apparent from our results.     

非双层脂对辅酶Q-细胞色素c还原酶呼吸控制率的影响

分离提纯的辅酶Q细胞色素c还原酶经胆酸盐透析法重组于各种脂质体上,发现脂质体中PE含量的升高可显著提高辅酶Q-细胞色素c还原酶的呼吸控制率.在PE含量为60%-80%时达到最高值,DOPE的L_x—H_Ⅱ的相变温度显著低于DEPE,脂酶体中DOPE含量的提高,可显著提高酶的呼吸控制率,而DEPE的影响很小,改变脂酶体中心磷脂的含量对呼吸控制率的影响较小.含有PE脂酶体中酶的CD谱419nm处的正峰,随PE含量的增大而增强,表明酶蛋白中血红素辅基的微环境有所改变.NBD-DOPE标记脂酶体研究了不同脂酶体的 L_x-H_Ⅱ的相变性质,表明PE含量的降低脂质体的相变温度上升甚至消失.     

卵巢癌细胞与腹膜间皮细胞相互作用对VEGF和bFGF表达的影响

目的探讨卵巢癌细胞与腹膜间皮细胞(HPMC)相互作用对血管内皮生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)表达的影响。方法用Millicell将卵巢癌细胞SKOV3与HPMC进行非接触性共培养,用RT-PCR检测细胞VEGF及bFGF mRNA表达,ELISA检测细胞条件培养液中VEGF及bFGF蛋白水平。结果共培养后,SK-OV3 VEGF及bFGF mRNA表达分别为3.62±0.23及3.41±0.25,条件培养液中VEGF及bFGF蛋白水平分别为(523.5±24.9)pg/ml及(156.4±17.3)pg/ml,与SKOV3单独培养时相比,差别均有显著性(P<0.01)。HPMC共培养后VEGF及bFGF mRNA表达分别为3.96±0.09及3.54±0.21,条件培养液中VEGF及bFGF蛋白水平分别为(1567.62±45.42)pg/ml及(682.9±33.7)pg/ml,均明显高于HPMC单独培养时的水平(P<0.01)。结论卵巢癌细胞与HPMC均可合成VEGF及bFGF;二者共培养时,相互刺激表达更高的VEGF及bFGF。