THE NATURE AND SOURCE OF ESR SIGNAL IN BILIRUBIN

The ESR signals of bilirubin-IXα were studied including the samples treated with free radical generating and inhibiting systems, i.e.X-X0., Fe/EDTA, SOD, mannitol/ascorbate, DTPA, KCN et al.These stable signals all comprise those originated from a semiquinone radical(g=2.0012)and superoxide radical(g₁₁=2.041, g_⊥=2.0040).The latter is shown to be bound with metal ionsespecially iron, chelated by bilirubin.The iron probably comes from bilirubin precursor---hemootobin.Active oxygen free radical scavengers may destroy these radicals.Kinetic curves of regeneration of the bilirubin radicals have been determined.Bilirubin is discussed as"active oxygen trap"in mammatians.     

KINETIC BEHAVIOR OF EPR SIGNAL I: INDUCTION EFFECTS IN INTACT ALGAE

Abstract— There is considerable evidence that the light-induced narrow EPR signal I at g = 2·0025 in green algae is a reflection of the turnover of the photosynthetic reaction center, P700. A lag period or induction effect of the formation of this signal, subsequent to a dark period in whole fresh cells, is similar to induction effects for the bleaching of P700. The rate of formation of the signal is slower the longer the preceding dark period. DCMU does not much affect the induction phenomenon, but heating the cells to 60° abolishes it. Some substance or process which exists in the intact cell is altered by light and is detectable by its effect on signal I and on the rate of light-induced oxidation of P700 and cytochrome.     

FUNCTIONAL MAPPING OF THE BRANCHED SIGNAL TRANSDUCTION PATHWAY THAT CONTROLS SPORULATION IN Physarum polycephalum

Abstract— Sporulation of starving plasmodia of Physarum polycephalum was found to be induced by far-red light, blue light or heat shock, each of which is perceived by a different input receptor system. The branched signal transduction pathway was mapped and the time-dependent formation of some of its components analyzed.     

THE TRANSFER OF LOW FREQUENCY SIGNAL BY THE NONNEUTRAL ELECTRON PLASMA IN EV DEVICE

The transfer of low frequency signal by the nonneutral electron plasma in EV deviceis investigated in this paper.The experiment results are consistent with approximate theoryand numerical calculation of rigorous theory,showing that the transfer is due to the wholemovement of the electron plasma.This work provides a practical method for measuring thetotal nonneutral electron plasma energy in similar EV device without destroying the plasmaState.     

ELECTRON PARAMAGNETIC RESONANCE SIGNAL II IN SPINACH CHLOROPLASTS—II. INFLUENCE OF PHOSPHORYLATION AND ELECTRON-TRANSPORT INHIBITORS

Abstract —The influence of several groups of inhibitors on the electron paramagnetic resonance Signal II of spinach chloroplasts was investigated. It was found that phosphorylation uncouplers that do not inhibit electron transport (gramicidin, valinomycin) have no effect. Likewise, inhibitors that block electron transport between the two photosystems are ineffective. However, reagents that can inhibit electron transport and also uncouple phosphorylation, such as phenylhydrazones (FCCP) or anilino-thiophenes (ANT 2p), will completely abolish Signal II in the dark. The signal is regenerated by red light and also by far-red light, but in the latter case only if cyclic electron transport is possible. These agents, in addition to discharging the water-splitting enzyme [ADRY effect, G. Renger, Biochim. Biophys. Acta (1972) 256, 428] were also found to inhibit cyclic electron flow. Light activation of Signal II in ANT 2p- or FCCP-treated chloroplasts by either red or far-red light can be suppressed by simazine or dichlorophenyl dimethylurea (DCMU) but not by other inhibitors that also inhibit linear electron flow. Evidence is provided which indicates that one functioning electron-transport system, either linear or cyclic, is necessary and sufficient for the enhancement of Signal II. The requirement for Signal II activation seems to be the reduction of plastoquinone. In ANT 2p- and FCCP-treated chloroplasts, a link probably exists between the water-splitting enzyme and the plastoquinone pool, bypassing Photosystem II; the unknown substance giving rise to Signal II may be located on such a sidepath.     

RED-BLUE-INTERACTION IN Mesotaenium CHLOROPLAST MOVEMENT: BLUE SEEMS TO STABILIZE THE TRANSIENT MEMORY OF THE PHYTOCHROME SIGNAL

Abstract— Fast chloroplast orientation in Mesotaenium from profile position to face position cannot be induced by either red (R) or blue (BL) light (in contrast to Mougeotia ). Rather interaction of light signals mediated by phytochrome and blue-light photoreceptor(s) is essential for the response. If both light treatments are separated in time, the irradiation sequence R-BL is much more effective than BL-R, i. e. a gradient of the far-red (FR)-absorbing form of phytochrome (Pfr) renders following BL highly effective, but BL cannot increase the responsiveness to following Pfr. The memory of a R irradiation before BL holds only for some minutes, indicating that the physiological activity of Mesotaenium -Pfr and its photoproducts is very short-lived. This transient signal mediated by Pfr can be transformed to a more stable internal signal by interaction with BL. The interaction process does not occur at the level of photoperception. Rather, early products of the phytochrome-initiated signal transduction chain interact with excited cryptochrome or an early product of it; Pfr can be removed by FR before the onset of BL. The internal signal stores the directional information of the Pfr-gradient, so that BL is now fully effective and induces chloroplast movement.     

AN IDENTIFICATION OF THE RADICAL GIVING RISE TO THE LIGHT-INDUCED ELECTRON SPIN RESONANCE SIGNAL IN PHOTOSYNTHETIC BACTERIA

Abstract— A reaction-center fraction isolated from Rhodopseudomonas spheroides chromatophores exhibits light-induced changes in its optical and electron spin-resonance (ESR) spectra. In particular, a bleaching at 870nm (P870) has been found to be closely correlated with the appearance of an ESR signal with a g factor of 2.0025 and a peak-to-peak line width of 10 G. The ESR signal is indistinguishable from light-induced signals found in chromatophores or whole cells.
A careful measurement of the spin concentration showed that the ratio of the light-induced spins to bleached P870 molecules is 1.1 ± 0.1. In addition the formation and decay kinetics are identical within experimental error under a variety of experimental conditions.
Previous work has shown that P870 is a bacteriochlorophyll molecule in a specialized environment and that the bleaching signifies oxidation. The present work provides strong evidence that the photo-bleaching of P870 produces the radical cation of bacteriochlorophyll, P870⁺, and that this radical is the source of the ESR signal in whole cells.
The quantum yield for the bleaching of P870 in reaction centers has been measured, using actinic light of wavelengths 880, 800, 760 and 680 nm. For light absorbed at 880 or 800 nm the efficiency is close to 100 per cent. In a coupled reaction, the oxidation of mammalian cytochrome c by P870⁺ proceeds with nearly the same efficiency.
The above results place definite limits on the possibilities for the identity of the primary acceptor. These possibilities are discussed.     

RAPID TRANSMISSION OF A PHYTOCHROME SIGNAL FROM HYPOCOTYL HOOK TO COTYLEDONS IN MUSTARD (Sinapis alba L.)

Abstract— In mustard ( Sinapis alba L.) cotyledons appearance of 'potential capacity' to phosphorylate is controlled by phytochrome (P_fr) through a threshold, all-or-none reaction. Phytochrome operates only if the hypocotyl hook is connected to the cotyledons for at least 2.5 min after the end of a 1 min inductive light pulse. Partial irradiations of hook and cotyledons show that in the case of induction of 'potential capacity' rapid transmission of the P_fr signal occurs from the hypocotyl hook to the cotyledons. Phytochrome within the cotyledons is totally ineffective in this regard. A 3 min red light pulse suffices for full transmission of the signal. It seems that an explanation of the facts we have observed requires a revision of the present views about communication between the organs of a plant.     

EFFECT OF HUMIDITY ON PHOTOINDUCED ESR SIGNAL FROM HUMAN HAIR

Abstract— Human red hairs, equilibrated at 79.8%, 58.0%, 32.3% humidity and at dry conditions, were irradiated with UV-visible (Λ > 290 nm) light. ESR intensity of the photo-induced transient free radicals was measured, at room temperature, as a function of time during and after exposure to light. Photoenhancement was found to be most pronounced in 79.8%-humidity conditioned hair and least in dry hair. The lifetimes of the transient free radicals in these samples were measured as 360s (79.8%), 180s (58.0%), 140s (32.3%), and 50s (dry). The gradual increase in lifetime as a function of humidity conditions was attributed to an increasing number of decay rates of the centers varying from fast to slow, the slow ones being unable to decay unless the fast ones do. This process is best described by a stretched exponential time function, I ( t ) = I _oexp[-( t/t _o)^α].     

KINETICS OF THE PHOTO-INDUCED EPR SIGNAL IN WHOLE-CELL RHODOSPIRILLUM RUBRUM: EFFECTS OF LIGHT INTENSITY, DARK ADAPTATION, TEMPERATURE, AND MICROWAVE POWER

Abstract— Kinetics of the bacteriochlorophyll (P870⁺) electron paramagnetic resonance signal photo-induced at room temperature in whole-cell Rhodospirillum rubrum exhibit transients which are strongly dependent upon the light-dark history of the cells. This paper reports a study of these kinetics as a function of actinic light intensity, light-dark history, temperature and applied microwave power. The simplest interpretation of the observed complexities in the kinetic curves is that the rate of formation and the rate of decay of P870⁺ are controlled by slow dark reactions of the electron-transport chain, and that the rate-controlling reaction is variable during the transition from a dark-adapted to a steady state in the light. With this interpretation, it is possible to measure or to infer order-of-magnitude estimates of the lifetimes of some of the slow reactions.     

EFFECTS OF PHOTOSYSTEM II INHIBITORS ON ELECTRON PARAMAGNETIC RESONANCE SIGNAL II OF SPINACH CHLOROPLASTS

Abstract— In isolated spinach chloroplasts the light-induced electron paramagnetic resonance signal (signal II) associated with the oxygen evolving photosystem (photosystem II) decays slowly and incompletely in the dark. Tris-washing, hydroxylamine, or carbonylcyanide m -chlorophenylhydrazone (CCCP) enhance the decay of signal II, which can still be induced by red (645 nm) but not by far-red (735 nm) radiation. Although 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) alone has no effect on signal II, it blocks the induction of signal II in the presence of hydroxylamine or CCCP. These data suggest that signal II is an indicator of an oxidized intermediate on the water-splitting side of photosystem II.     

PHYTOCHROME- and BLUE PIGMENT-MEDIATED LEAF MOVEMENTS: EXPERIMENTAL APPROACH IN THE SIGNAL TRANSDUCTION

Abstract— Leaflet movements of Cassia fasciculata are induced by transferring leaves from light to darkness or from darkness to light. Phytochrome mediates the dark-induced closure whereas a blue and far red light absorbing pigment (cryptochrome?) is the photoreceptor triggering the light-induced opening. These movements are the result of reversible turgor variation driven by ionic migrations (H+, K+, Cl^?) in cortical parenchyma cells of motor organs (“pulvini”) localized at the leaflet base. Calcium plays a predominant role in the regulation of the movements as shown by the inhibitory effects of chelators (EDTA, EGTA), intracellular antagonist TMB-8 and by the promoting effect of ionophore A 23187. Compounds known as calcium channel blockers (LaCl₃, verapamil and nifedipine) inhibited whereas Bay K 8644, a calcium channel activator, promoted the phytochrome-mediated movement. In contrast, all these calcium channel modulators had no effect on the blue pigment-mediated movement. From these results, it is suggested that calcium is not mobilized in the same manner in the two types of movements: possibly from external stores in the phytochrome-mediated response and from internal stores in the blue pigment-mediated response. Calcium acts possibly through calmodulin as suggested by a modification in the kinetics of the movements induced by inhibitors of calmodulin action (trifluoperazine, R 24571, W-7). The unexpected promotion of the movements by these inhibitors shows that calmodulin action on the ion migrations is not simple and direct. Experimental observations suggested that regulation might be done through cAMP metabolism. db-cAMP promoted the movements. Compounds known either to activate adenylate cyclase (prostaglandins, forskolin) or to inhibit phosphodiesterase (imidazolidinones, ICI 58301) induced the same modifications as db-cAMP. By contrast, a phosphodiesterase activator (imidazole) inhibited the movements.     

直接大容量样品注射和窄孔径柱接合及信号平均化分析水样中有机物

将大容量水样（５００μＬ至５ｍＬ）注射到并保持在Ｎａｆｉｏｎ管内,用逆流氮气将扩散穿过Ｎａｆｉｏｎ管的水蒸气带走。将所得的样品气流引到５０μｍ内径的开口管毛细管柱内。柱头热解吸调制器对所接受的样品的均匀调制得到浓度脉冲,一个脉冲产生一组色谱图,通过对这样一系列的快速色谱图的信号平均比能得到特殊的多重气相色谱图─—整体样品色谱图。热解吸调制器是通过将导电涂料涂到５０μｍ的分析柱的前端５．０ｃｍ一段而制得的。施加到导电薄膜上的电流脉冲将调制器段及其内部的固定相加热,释放出作为浓度脉冲的保留物质。     

SMALL SIGNAL ADMITTANCE OF METAL CHLOROPHYLL a|Hg PHOTOVOLTAIC SANDWICH CELLS

Abstract— …The ac admittances of metal I chlorophyll a|Hg sandwich cells are shown to depend upon the chlorophyll (Chi) layer thickness, the aggregation state of the Chi, the light-dark environment of the cells and the nature of the metal. The results suggest the presence of different but not independent charge transport processes in these cells. One process gives rise to a broad dispersion in the frequency dependent capacitance and conductance. This process is observed in all cells and is most readily ascribed to a hopping or tunneling of charge carriers across potential energy barriers. Another mechanism which is detected only with crystalline Chi and only with certain metal substrates is ascribed to interfacial polarization. A model circuit incorporating these interpretations yield calculated admittance data which approximate those measured experimentally.     

电化学聚对苯膜的现场ESR及其性能研究

本文用现场电化学-ESR联合测试的技术, 对电化学聚对萃膜在浓H_2SO_4中的性质进行了研究, 结果表明: 聚对苯膜具有高的电导率和相对低的自旋磁化率, 极化子与偶极化子为主要导电者, 并在一定的电位下相互转化, 自旋粒子有很大的离域性。膜中链与链之间可能存在部分的氧桥结构, 而引起体系结构的某些变化, 使聚对苯膜的电导提高以及掺杂容易进行。掺杂量受电位控制, 浓H_2SO_4中的HSO_4~-嵌入/脱嵌的电化学可逆性很好, 最大掺杂量可相当于每5个苯环单元氧化出一个正电荷, 可望将电化学聚对苯用作稳定的二次电池电极材料。     

ELECTRON PARAMAGNETIC RESONANCE SIGNAL II IN SPINACH CHLOROPLASTS—I. HIGH RESOLUTION SPECTRA AND MORPHOLOGICAL LOCATION

Abstract —The electron paramagnetic resonance Signal II of spinach chloroplasts was recorded under high-resolution conditions. The signal is asymmetric, has five lines of unequal intensity and splitting, a derivative linewidth of 20.0 G, and a g -value of 2.0051. The latter value varies between 2.0045 and 2.0052 since other signals contribute to the center portion of the spectrum. Signal II is present in dark-adapted leaves and chloroplasts at a concentration of 50 per cent of the maximum light signal. It is not exhibited by stroma lamellae but is seen in grana thylakoid fractions. The maximum concentration of the material providing Signal II is found in a fraction (40 K) which has a very low Photosystem II activity. The unknown substance giving rise to Signal II may not be required for either Photosystem I or Photosystem II activity. Evidence presented here indicates that Signal II probably is not due to a free, mobile plastosemiquinone or a free, mobile plastochromanoxyl radical.     

ULTRAVIOLET RADIATION INDUCES A CHANGE IN CELL MEMBRANE POTENTIAL in vitro: A POSSIBLE SIGNAL FOR ULTRAVIOLET RADIATION INDUCED ALTERATION IN CELL ACTIVITY

The regulation of a transmembrane ionic gradient, reflected by the cellular membrane potential, has been shown in several cell systems to be involved in the regulation of cell function. This investigation presents evidence that biologically relevant doses of ultraviolet radiation (UVR) will alter the membrane potential of keratinocytes in vitro. Estimation of the relative change in the steady-state membrane potential of the murine keratinocyte cell line PAM 212, the murine myelomonocytic cell line P388D1, and normal human keratinocytes in culture, were made through the use of the lipophilic cationic membrane potential sensitive probe; triphenylmethylphosphonium. Our observations indicate that UVR composed primarily of UVB (280-320 nm) radiation at doses as low as 100 J/m2 can induce a depolarization in the murine cell lines and a hyperpolarization in human keratinocytes. Evidence suggests that this difference in the direction of the membrane potential response reflects a difference in Na+/K+ ATPase activity following UVR. These results suggest a possible mechanism for modulation of keratinocyte activity induced by UVR.     

纺织品中五氯苯酚残留量测量不确定度评定

采用气相色谱法测定纺织品中残留的五氯苯酚含量,对整个测量过程的不确定度来源进行了分析,并对不确定度各个分量进行了评定与合成。当五氯苯酚测定结果为0.570mg/kg时,扩展不确定度为0.054mg/kg,并给出了检测结果不确定度表达式。