THE EFFECT OF PHOSPHORYLATION UNCOUPLERS AND ELECTRON TRANSPORT INHIBITORS UPON SPECTRAL SHIFTS AND DELAYED LIGHT EMISSION OF PHOTOSYNTHETIC BACTERIA

Abstract— Delayed light emission (measured 4 msec after excitation) and the light-induced red shifts of the bacteriochlorophyll and carotenoid absorption bands of chromatophores of Rhodopseudomonas spheroides were inhibited by a variety of reagents. These included anti-mycin A, NQNO, CCCP, desaspidin, quinacrine, chlorpromazine, 2,4-dinitrophenol, gramicidin D, Triton X-100 and valinomycin in the presence of potassium, cesium or ammonium ions. Delayed light emission was enhanced by orthophenanthroline, ethanol, succinate and glutathione.
Delayed light emission from chromatophores of Rhodospirillum rubrum was attenuated during photophosphorylation but restored approximately to its initial value in the presence of oligomycin. Since the delayed light and band shifts are inhibited under conditions which tend to deplete or block the formation of high energy phosphorylation intermediate, it is suggested that the presence of a high energy intermediate is a prerequisite for the appearance of each of the three phenomena.     

SPECTRAL CHARACTERISTICS AND MECHANISM OF CHEMILUMINESCENCE FROM TRYPTOPHAN SOLUTIONS INDUCED BY UV-IRRADIATION

The spectral distribution of the chemiluminescence, fluorescence and phosphorescence of tryptophan aqueous solutions irradiated with high and low pressure mercury lamps has been measured. The blue emission bands in the region of 380–520 nm observed both in the chemi- and photoluminescence, as well as an absorbance increase at 230 and 330 nm, indicate oxidative degradation of tryptophan leading to the formation of derivatives of N-formylkynurenine, xanthurenic and anthranilic acids. Red emission bands at 630 and 705 nm in the spectrum of the chemiluminescence, an enhancement of light intensity by D₂O and its decrease by NaN₃ and DABCO suggest a partial contribution of O₂(¹Δ_g) to the photooxidation and chemiluminescence of tryptophan. The enthalpy of the exergonic reactions, leading to the formation of luminescing products, was calculated to average -270 kJ-mol.     

SPECTRAL DEPENDENCE OF UV-INDUCED IMMEDIATE AND DELAYED APOPTOSIS: THE ROLE OF MEMBRANE AND DNA DAMAGE

Abstract— The phototoxicity of each waveband region of UV radiation (UVR), i.e., UVA (32CM100 nm), UVB (290–320 nm) and UVC (200–290 nm), was correlated with an apoptotic mechanism using equilethal doses (10% survival) on murine lymphoma L5178Y-R cells. Apoptosis was qualitatively monitored for DNA "ladder" formation (multiples of 200 base pair units) using agarose gel electrophoresis, while the percentages of apoptotic and membrane-permeabilized cells were quantified over a postexposure time course using flow cytometry. The UVA1 radiation (340–400 nm) induced both an immediate (<4 h) and a delayed (>20 h) apoptotic mechanism, while UVB or UVC radiation induced only the delayed mechanism. The role of membrane damage was examined using a lipophilic free-radical scavenger, vitamin E. Immediate apoptosis and membrane permeability increased in a UVA1 dose-dependent manner, both of which were reduced by vitamin E. However, vitamin E had little effect on UVR-induced delayed apoptosis. In contrast, the DNA damaging agents 2,4- and 2,6-diaminotoluene exclusively induced delayed apoptosis. Thus, immediate apoptosis can be initiated by UVA 1-induced membrane damage, while delayed apoptosis can be initiated by DNA damage. Moreover, the results suggest that immediate and delayed apoptosis are two independent mechanisms that exist beyond the realm of photobiology.     

化学发光分析法应用进展

对近年来化学发光分析法的研究应用最新进展作了评述，包括化学发光试剂的类型，化学发光在无机、有机及药物分析中的应用，全文引用文献105篇。     

THE TEMPERATURE DEPENDENCE OF PHYTOCHROME TRANSFORMATIONS

Abstract— The kinetics of phytochrome transformation were examined over a 30°C temperature range (+5° to–25°C) in 75% glycerol. Two new intermediate reaction stages are described for the transformation of the red-absorbing form, P _r to the far-red absorbing form, P _fr The free energies, enthalpies and entropies of activation were obtained for five of the six reaction stages observed in the transformation of P _r to P _fr and for the two reaction stages observed in the reverse process. All exhibited positive entropies of activation with the maximum being 25 entropy units. The results suggest that the phototransformations between P _r and P _fr consist of relaxation processes beginning with the intermediate produced immediately upon absorption of a quantum of light and ending with either P _r or P _fr.     

流动注射-化学发光分析法的发展

对流动注射一化学发光分析法的发展作了评述,特别叙述了在此领域中的研究工作的进展,对此方法的基本原理也作了简要介绍（引用文献67篇）。     

FIBER-OPTIC PLANT TISSUES: SPECTRAL DEPENDENCE IN DARK-GROWN AND GREEN TISSUES*

Abstract— The fiber-optic properties of etiolated plant tissues can be used to detect and characterize pigment absorption in vivo. Transmission spectra of light guided through several monocot and dicot etiolated tissues show a decreasing red/far red ratio with increasing tissue length. Absorption bands attributable both to vacuolar pigments such as anthocyanins and to chloroplast pigments lead to the conclusion that the guided light passes through both vacuole and cytoplasm. As etiolated tissue becomes green under white light treatment, the red/far red ratio also changes, the nature of the change depending upon the tissue involved. The blue/red ratio also changes both with increasing length of etiolated tissue and during the greening process, with the changes again dependent on the tissue involved. The spectral dependence of the light-guiding phenomenon in dark grown and green plants may have implications for physiological responses mediated by phytochrome.     

TEMPERATURE AND VISCOSITY DEPENDENCE OF FLUORESCENCE QUENCHING BY OXYGEN IN MODEL SYSTEMS

Abstract— The bimolecular rate constant, k _q, for the quenching of the fluorescence of pyrenebutyric acid and naphthaleneacetic acid by molecular oxygen has been studied as a function of temperature and viscosity, η. Fluorescence lifetime measurements were used to monitor the degree of quenching. Glycerol-water and sucrose-water mixtures were used to increase the bulk viscosity. Plots of log k _q vs log η show deviations from Stokes-Einstein behavior, but the data are consistent with the patterns that have been observed for other diffusion limited reactions. This work provides background information, regarding the viscosity dependence of oxygen quenching reactions, which is essential for the correct interpretation of oxygen quenching/viscosity dependence studies with more complex systems (i.e. quenching of tryptophan residues in proteins).     

SPECTRAL DEPENDENCE OF A SINGLE AND A SUBSEQUENT SECOND LIGHT PULSE INDUCING BARLEY LEAF UNFOLDING

The unfolding of etiolated barley leaves was induced by two short pulses of light separated by a dark interval. For certain wavelengths of light the effect of the “second light pulse was enhanced when the pulse was given after a 300–2000 s dark interval as compared with its effect when the two light pulses were given simultaneously. We investigated the spectral dependence of the effect of the first, inducing light flash and of the effect of the second Light flash given after a 500 s dark interval. The spectral actinity for the effect of the first flash showed phytochrome involvement. The spectral actinity for the effect of the second light flash, however, was shifted towards shorter wavelengths and the inductive action of red and far red light was attenuated.     

SPECTRAL CHARACTERISTICS OF THE EXCITED STATES OF THE PRODUCT OF THE CHEMILUMINESCENCE OF LUMINOL*

Abstract— In dimethylsulfoxide the emission spectrum of luminol chemiluminescence is red-shifted by 300 cm^-1 from the photoexcited fluorescence of the product 3-aminophthalate dianion, while in aqueous solvent the two spectra are identical. The spectral properties of the product dianion have been measured in aqueous solvent and in a number of aprotic solvents, both at room temperature and at 77°K. The ground states and the excited states from which emissions are observed are characterized. Two alternatives are presented to explain the aprotic emission spectra.     

TEMPERATURE DEPENDENCE OF CHLOROPHYLL(IDE) SPECTRAL SHIFTS and PHOTOACTIVE PROTOCHLOROPHYLLIDE REGENERATION AFTER FLASH IN ETIOLATED BARLEY LEAVES

Abstract— Absorbance spectroscopy at 77 K was used to investigate the effect of temperature on in vivo chlorophyllide shifts and photoactive protochlorophyllide regeneration after a saturating flash, which transformed all protochlorophyllide to chorophyllide. Photoactive protochlorophyllide present in darkness was stable up to 40°C. The rate of Shibata shift and protochlorophyllide regeneration after flash were strongly temperature dependent in the range 0–25°C. At 0°C, the shift was still observed but no regeneration occurred. Only slight effects were observed in the range 25–40°C. At all temperatures, the process of protochlorophyllide regeneration was significantly slower than the Shibata shift. The final chlorophyll shift from 672 to 674 nm was observed up to 40°C. The implication of these results concerning the pigment-protein interactions during the Shibata shift are discussed.     

SPECTRAL DEPENDENCE OF SOME UV-B AND UV-C RESPONSES OF Tetrahymena pyriformis IRRADIATED WITH DYE LASER GENERATED UV

Abstract— We have generated UV-B and UV-C radiations using a flashlamp driven tunable dye laser combined with frequency doubling crystals. Using this novel UV source, we have investigated lethality and its modification by growth phase, photoreactivation and caffeine in Tetrahymena pyriformis at 254 nm and from 260–315 nm in 5 nm steps. From the observed responses we have constructed action spectra for lethality, with or without caffeine (a repair inhibitor) and under conditions of photoreactivation. We have also estimated quantum efficiencies for these responses. Our observations suggest that complex changes in response occur at several wavelengths over the UV-C and UV-B regions.     

化学发光法在药物分析中的应用

化学发光法因具有设备简单、灵敏度高等特点而被广泛采用。文中对近年涉及药物、药物在人体中的代谢产物及生命相关物质的化学发光分析进行了评述,引用文献87篇。     

环氧交联网T_g转变的tanδ-T曲线解析

本文系统地研完了预聚物分子量、固化剂配比和固化条件对环氧交联网T_g松弛内耗峰松弛时间分布的影响。本实验和理论研究结果首次证明了环氧交联网T_g松弛过程具有单一松弛时间描述的线性标准固体的特征,与预聚体分子量、固化剂配比和固化条件无关。此结果可用环氧交联网的两相结构特征加以解释。     

SPECTRAL AND TIME DEPENDENCE STUDIES OF THE ULTRA WEAK BIOLUMINESCENCE EMITTED BY THE BACTERIUM Escherichia coli

Abstract— Weak luminescence was detected using photon counting equipment, from oxygenated, liquid cultures of Escherichia coli during two stages of its growth cycle. The first period of emission occurred during the exponential phase of growth and comprised a UV(210–330 nm) band and a visible region(450–620 nm) band, the total intensity being (1.65 ± 0.12) x 10³ counts s^-1. The second period of emission occurred during the stationary phase of growth and comprised only a visible region(450–620 nm) band of intensity (8.72 ± 0.15) x 10³ counts s^-1. When the growth temperature was raised from 306.15 to 310.15 K, the above emission intensities were approximately halved, but the spectra were not changed significantly. No luminescence was observed at either temperature when the E. coli was grown anaerobically. The visible region luminescence was attributed to excited carbonyl groups and excited singlet O₂ dimers formed during the decomposition of lipid peroxides. The UV component was tentatively assigned to oxidative side reactions accompanying the synthesis of proteins.     

FI-化学发光法测定吡哌酸

基于吡哌酸对Ce(Ⅳ) SO2-3化学发光体系有较强的增敏作用,结合流动注射分析技术,提出了吡哌酸的化学发光测定法。方法选择性好、灵敏度高。吡哌酸在1.0×10-7～1.0×10-5g·ml-1浓度范围内与化学发光分析信号呈线性关系,其检出限为4×10-8g·ml-1。对5.0×10-6g·ml-1的吡哌酸进行11次连续测定,相对标准偏差为2.5%。方法已成功地应用于片剂中吡哌酸含量的测定。     

5A66铝合金光谱分析标准样品的制备和定值

阐述5A66铝合金光谱分析标准样品的制备工艺，数据处理及定值结果，在制备过程中，采用自制专用中间合金，分步调整化学成分等先进工艺技术，保证了制备的标准样品成分均匀，采用极差法进行均匀性检测，多家协同定值，定值准确。     

新型镁合金Mg-Al-Zn-Y光谱标准样品的制备和定值

采用双层安全炉熔炼镁合金和环壁式除渣法清除结晶器中的氧化皮和夹渣等技术,研制了新型镁合金Mg-Al-Zn-Y光谱标准样品.考察了标准样品的均匀性和稳定性,该标准样品有效期为5年.使用先进的数据处理软件(StndMtrl),对多家单位协作分析定值原始数据进行检验和计算,得到标准样品的标准值和标准偏差.用化学法对标准样品进...     

STUDIES ON THE IMBIBITIONAL CHILLING INJURY AND THE REPARATION OF DAMAGED MEMBRANE SYSTEMS IN SOYBEAN SEEDS

Two soybean (Glycine max Merrill.) cultivars, Jilin No. 3 and Heihe No. 3 which are sensitive to imbibitional chilling injury were used to investigate the difference between the damaged seeds and control in a series of items, including the leakage of soaking solution (K~+, Na~+, Ca~(++), Mg~(++), Fe~(++) and Zn~(++) various mineral elements, phosphorus, sugars, proteins and more than 10 amino acids, etc.), ATPase activity, the morphological character of the cell wall and the development of organelles. Comparisons between the PEG priming and the chilling injury seeds were also conducted for confirmation.This paper deals with the above experimental results and some mechanisms about the imbibitional chilling injury in seeds are also discussed. The authors stress that investigation of the mechanism of imbibitional chilling injury must be conducted from the points of the reparation in a broad sense, not only limited to the membrane itself, but also including the physical membrane reparation as well as recove