CORRELATION BETWEEN ABSORBANCE CHANGES AND A PHYSIOLOGICAL RESPONSE INDUCED BY BLUE LIGHT IN NEUROSPORA

Abstract— Absorbance changes due to the photoreduction of a b -type cytochrome are associated with many biological blue light-controlled processes. Evidence is presented for their causal relationship with the perception of light which induced conidia formation under conditions of starvation in Neurospora crassa mutant albino band, but not with light-induced phase shifts of conidiation bands.     

RELATIONSHIP BETWEEN PHYTOCHROME PHOTOCONVERSION and RESPONSE

Abstract— The action of phytochrome on appearance of NADH-dependent glutamate synthase (NADH-GOGAT) and ferredoxin-dependent glutamate synthase (Fd-GOGAT) was studied in the cotyledons of the mustard ( Sinapis alba L.) seedling. It was found that the [P_fr]-response curves are composed of two branches with two very different slopes (a₁ a₂). This explains the biphasic fiuence response curves reported previously. While a, is the same with both enzymes, a, is much higher in NADH-GOGAT than in Fd-GOGAT. However, the transition from the high (a₁) to the low (a₁) slope occurs at the same P_fr/P_tot ratio irrespective of the steepness of a₁ While the appearance of NADH-GOGAT is very sensitive to small amounts of P_rr (high a₁), the response is not sensitive to the "High Irradiance Reaction" (HIR) of phytochrome. On the other hand, appearance of Fd-GOGAT (relatively low a₁) exhibits the usual HIR. It is concluded that the presently available models of phytochrome action, including the dimeric model, are not adequate to account for the actual data. At present it appears that a multiplicity of primary actions of phytochrome exist, and that it is the availability of the primary reactant (X, _1,2,3) which determines transduction or non-transduction of the phytochrome signal.     

THE IN VIVO SPECTROPHOTOMETRIC ASSAY OF PHYTOCHROME IN TWO MATURE DICOTYLEDONOUS PLANTS*

Abstract— Mature Sinapis alba L. and Impatiens parviflora DC. were treated with the herbicide norfiuorazon prior to development of the third or second leaf, respectively. This treatment yielded a partially bleached plant capable of normal growth and development. The bleached leaves were used for spectrophotometric phytochrome assay. In mature plants an almost constant level of phytochrome is maintained under continuous white light. The dark kinetics and the response of the phytochrome system to light of various qualities provide further evidence of the stable character of the phytochrome system.     

PHYSIOLOGICAL RELATIONSHIPS BETWEEN PHYTOCHROME EFFECTS ON INTERNODE EXTENSION GROWTH AND DRY MATTER ACCUMULATION INLIGHT-GROWN MUSTARD

The physiological relationships between the effects of phytochrome photoequilibrium (Pfr/P) on internode extension growth and dry matter accumulation were investigated in white light (WL)-grown Sinapis alba L. seedlings. After 11 days under continuous WL, the seedlings were exposed: (a) to pulses of light providing different Pfr/P, followed by 24 h darkness (D); (b) to pulses of light providing different Pfr/P, followed by 3 h D and 24 h continuous WL; (c) to continuous WL with or without supplementary far-red light (to reduce Pfr/P); or (d) to pulses of light providing different Pfr/P followed by D, in factorial combination with either water or a saturating (0.2 M) sucrose solution applied to one of the leaves. In D (“a” and “d”) low, compared to high Pfr/P increased both internode extension growth and dry weight to the same extent. Under WL (“b” and “c”) low PfrlP promoted internode extension growth but had no proportional effects on internode dry weight. Sucrose promoted internode extension growth with a lag of at least 8 h (compared to the rapid effect of low Pfr/P) and did not reduce the effect of low Pfr/P. These results indicate that Pfr/P effects on internode extension growth are not the consequence of changes in photoassimilate translocation from the leaves. Under WL, PfdP effects on internode length occur partially at the expense of internode dry matter per unit length.     

CORRELATION BETWEEN INTERFACIAL TENSIONS AND MICELLAR STRUCTURES

It is shown that results of surface and interfacial tension measurements can be used to predict the type of micelles and of liquid crystalline phases which are formed in binary and ternary surfactant solutions. In particular it is possible to predict the position of l.c. cubic phases in ternary systems consisting of surfactant, hydrocarbon and water. Data to demonstrate the conclusions were obtained on the surfactants Alkyltrimethylammoniumbromides, Alkyldimethylaminoxides and Alkyldimethylphosphinoxides. It was found that the interfacial tension of a dilute micellar solution against a reference hydrocarbon is a most sensitive and indicative parameter for the prediction of the different structures. Large changes of the interfacial tension were observed for the three systems having the same hydrocarbon chainlength. The value of the interfacial tension directly reflects also the amount of hydrocarbon which can be solubilized in the micellar solution. Interfacial tensions larger than 1mN/m are indicative of globular micelles while interfacial tensions between 0.1 and 1 mN/m indicate the formation of rods. Values below 0.1 mN/m indicate disclike micelles or lamellar phases.

The interfacial tension depends somewhat on the kind of hydrocarbon which is used for the measurements. It is observed that for several surfactant solutions the interfacial tension passes through a shallow minimum when the chainlength of the hydrocarbon is increased from six to sixteen.     

A SPECTROPHOTOMETRIC METHOD FOR CHLOROPLAST ATP SYNTHETASE ASSAY

Ultraviolet-B (UV-B,280–320 nm) irradiance was calculated for more than 1200 sites in Asia to characterize the spatial and temporal variation in the present UV-B climate for rice-growing regions. The analytical model of Green et al. (Photochem. Photobiol. 31 ,59–65, 1980) was used to compute UV-B irradiance for clear skies using satellite-observed ozone column thickness and local elevation data. Ground-based observations of cloud cover were then used to approximate the average effect of cloud cover on UV-B irradiance using the approach of Johnson et al. (Photochem. Photobiol. 23 ,179–188, 1976). Over the geographic range of rice cultivation, the maximum daily effective UV-B irradiance (UV-B_BE), when weighted according to a general plant action spectrum, was found to vary approx. 2.5-fold under both clear and cloudy sky conditions. Under clear skies, the timing of maximum solar UV-B_BE changed with latitude and varied from February-March near the equator to July-August at temperate locations. Cloud cover was found to alter the season of maximum UV-B_BE in many tropical regions, due to the pronounced monsoonal climate, but had little effect on UV-B seasonality at higher latitudes. Under a climate resulting from a doubling of atmospheric carbon dioxide, estimated UV-B using predicted cloud cover was found to change by up to 17% from present conditions in Thailand. Both latitudinal and seasonal variation in solar UV-B radiation may be important aspects of the UV-B climate for rice as cultivars differ in sensitivity to UV-B and are grown under diverse conditions and locations.     

A SIMPLE MODIFICATION OF THE SPECTROPHOTOMETER FOR RAPID PHYTOCHROME ASSAY

Abstract— A simple, low cost modification of a conventional single wavelength spectrophotometer (e.g. Cary 118C) enables one to quantitate phytochrome in crude extracts and purified phytochrome preparations without the use of a dual-wavelength ratio spectrophotometer.     

INTERACTION BETWEEN PHYTOCHROME AND THE BLUE LIGHT PHOTORECEPTOR SYSTEM IN Mougeotia*

Abstract— Face-to-profile chloroplast movement in Mougeotia was induced by sequences of strong blue and red short irradiations. This type of response occured only when blue light was applied prior to or simultaneously with red light, and far-red irradiation was necessary after the sequence to cancel the remaining gradient of the far-red absorbing form of phytochrome P_fr. The dependence of the response magnitude on blue and red light sequences was studied for a wide range of light durations and dark intervals. The relationship between the response and the dark interval points to the lack of direct coupling between phytochrome and blue-absorbing “cryptochrome”. It was postulated that a photoproduct having a life-time of2–3 min is formed by the blue-light-mediated reaction. This photoproduct interacts with phytochrome during its transformation or with its final P_fr form.     

单轴取向PET薄膜的α松弛与力学行为的相关性

本文用动态力学方法研究了在不同温度和速度下单轴自由辐拉伸的聚对苯二甲酸乙二酯薄膜的非晶区状态,表明从熔体骤冷的非晶态试片在不同热拉伸条件下拉伸,可以得到非晶状态有显著差别的单轴取向薄膜。它们的非晶状态可以用动态力学温度谱的α峰的高度,形状和位置来表征。具有不同非晶状态的试样的储能模量E′(25℃)、屈服应力、负荷-伸长曲线与α松弛的参数以及其他结构参数间有很好的相关性。在一定的条件下热拉伸温度和速度存在Arrhenius型的速度-温度变换关系。     

DETERMINATION OF EXTINCTION COEFFICIENTS OF OAT PHYTOCHROME BY QUANTITATIVE AMINO ACID ANALYSES

Abstract— Previously published extinction coefficients for phytochrome were based on indirect colori-metric estimates of protein weight, mostly by the Lowry method, using bovine serum albumin as a standard. This paper reports revised values based on quantitative amino acid analyses of highly purified phytochrome. The molar extinction coefficient of the red-absorbing form of phytochrome with 120000mol. wt subunits was found to be approximately 102000cm"₁ per 120000moi. wt at 667nm. The molar extinction coefficients at 667 nm for phytochrome with 120000 mol. wt subunits and for the 60000 mol. wt chromopeptide of P_r were found to be approximately the same for samples of equivalent purity. Included in the amino acid analyses of phytochrome with 120000 mol. wt subunits are values for cysteine (11) and cystine (1), measured by two different techniques that gave the same results and agreed well with the estimate of total half-cystine (14) obtained by an independent method. Tryptophan was quantitated by analysis of a p-toluene sulfonic acid hydrolysate.     

ON THE PHYSIOLOGICAL SIGNIFICANCE OF DARK REVERSION OF PHYTOCHROME IN THE MUSTARD SEEDLING

Abstract —We present physiological evidence using the threshold control of lipoxygenase synthesis† by P_fr in the mustard seedling (LOG response) that there is no dark reversion of phytochrome
which would be relevant for this response. Such Ptr which can be detected with the lipoxygenase response disappears exclusively through degradation with a half-life of 45 min at 25°C. De novo synthesis of P*_r in the hypocotylar hook takes place at a constant rate (zero order rate constant) irrespective of the level of P_r or P*_tot, i.e. there is no detectable feedback control of P_r synthesis during the period of experimentation. The data of the present paper are consistent with a quantitative phytochrome model (Scheme 1) which has been advanced and treated quantitatively in the companion paper (Oelze-Karow and Mohr, 1976).     

亚微米分子筛粒径与性能的关联研究

对实验室合成的不同粒径的NaY分子筛进行了性能研究,表明比表面积、酸量随着粒径的减小而增加,粒径太小的分子筛其稳定性、活性低,不能满足FCC催化剂的使用要求,应用于FCC催化剂的分子筛合适粒径为500nm～800nm.     

Ni80P20合金的非晶化度与催化活性的关联

采用淬冷法,通过改变冷却铜辊的转速,得到了一系列具有不同非晶化度的Ｎｉ８０Ｐ２０合金材料。以乙炔加氢为探针反应的催化研究结果表明,合金的催化活性随非晶化程度的增加而增加,同时,非晶态合金具有比相应的晶态金合明显优良的催化稳定性,ＸＲＤ和ＡＥＳ深度分析显示：在氧化－还原活化处理过程中,相对晶态合金而言,非晶态合金显示明显的“惰性”,活化后的表面上含有较多的对加氢反应有促进作用的氧化镍相互作用的结构。     

最快结晶速率温度与结晶参数的关系

以经典的结晶速率与温度的关系为基础,对T_(c,max)与结晶参数的关系进行了研究.结果表明,T_(c,max)同平衡熔融温度(T_m)的比值仅与成核参数(φ)同扩散活化能(E_d)之比有关.高聚物的结晶过程可用二次成核模型近似.当结晶速率与温度的关系采用下式时 G=G_0exp[-E_d/RT-φT_m~2/T~2(T_m-T)]T_(c,max)与结晶参数的关系为 T_(c,max)=2/3T_m[1-(1+9α)~(1/2)cos(1/3)arccos1/(1+9α)~(3/2)+240°]或 α=φR/E_d=T_(c,max)(T_m-T_(c,max)~2/T_m?2(3T_(c,max)-2T_m)     

荷移光度法测定双嘧达莫

用光度法研究了双嘧达莫与氯冉酸之间发生的电荷转移反应,其中双嘧达莫是电子给予体,氯冉酸是电子接受体,反应介质是乙醇丙酮混合溶剂。应用等摩尔连续变换法和摩尔比法测得荷移络合物的组成为1∶1,稳定常数为3.9×104。络合物在526nm波长处有最大吸收,双嘧达莫浓度在10～380mg·L-1范围内服从比耳定律,相关系数为0.9996,表观摩尔吸光系数为1.34×103L·mol-1·cm-1,回收率为98.4%,测定结果的相对标准偏差为1.14%。应用该法可以快速测定双嘧达莫片中有效成分的含量,结果满意。     

RED/FAR-RED PHOTOREVERSIBILITY: NOT AN APPROPRIATE PHYTOCHROME ASSAY FOR RED-LIGHT PREIRRADIATED CORN COLEOPTILES

Abstract— Based on measurements with a single beam spectrophotometer, it has been found that subsequent red/far red irradiation cycles, which are usually given to monitor phytochrome content by dual wavelength spectroscopy, induce chlorophyll-related absorption changes in maize coleoptiles. Therefore, the difference signal, usually measured between 730 and 800 nm or 660 and 730 nm after saturating red and far red irradiations, does not represent solely the phytochrome content of preirradiated samples.     

添加剂分子结构特征与灵武煤水煤浆浆体各性质间匹配规律研究

研究了分子结构特征不同的十六种添加剂与灵武煤成浆性、流变特征以及静态稳定性间的匹配规律。实验结果表明，添加剂的主结构特征、取代基的性质、磺化度及聚合度与灵武煤浆体各性质间存在明显的匹配规律，其中，主结构特征、聚合度和磺化度对灵武煤浆体各性质的影响最为显著。分散性能强的添加剂不利于灵武煤煤浆流变特性的改善，而在一定范围内磺化度的增加能明显改善浆体的流变特性；添加剂的聚合度是影响灵武煤浆体的成浆性和稳定性的重要因素。     

琥乙红霉素与紫色素的荷移反应及其测定

建立了一种快速测定琥乙红霉素的荷移分光光度法。琥乙红霉素与紫色素在乙醇-水介质中发生电荷转移反应,荷移络合物在546 nm波长处有最大吸收,表观摩尔吸光系数为9.18×103L.mol-1.cm-1,络合物的组成为1∶1,稳定常数为1.9×105。药物质量浓度在0~90 mg.L-1范围内服从比耳定律,相关系数为0.999 7,当琥乙红霉素质量浓度为40 mg.L-1时,6次测定结果的相对标准偏差为1.24%。测定了琥乙红霉素片剂中有效成分的含量,并与药典方法进行比较,结果基本吻合。