Determination of the content of endogenic porphyrins in children and adolescents with thyroid pathology

The aim of the present work was to use the fluorescence method for elucidating the laws governing porphyrin exchange in children with thyroid pathology to estimate the possibility of creating in future nontradiational approaches to the diagnosis of oncologic diseases. A systematic investigation of the level of photo- and coproporphyrins in the erythrocytes of children and adolescents of from 8 to 17 years old with thyroid pathology (cancer, ganglia, autoimmune thyroiditis) is carried out. A control group of the same ages was examined for comparison. It is shown than in all of the pathologies considered one observes an individual character of porphyrin variation, which affects the content of protoporphyrin and corproporphyrin in erythrocytes. A decrease in the level of endogenic porphyrins in the blood of children with malignant tumors is discovered. Institute of Molecular and Atomic Physics of the Academy of Sciences of Belarus, 70, Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 748–752, November–December, 1997.     

Luminescence studies of porphyrin exchange in pregnant females

Results of investigations of the level of proto- and coporphyrins in erythrocytes and excretion of coproto- and uroporphyrins from the organism for two control groups are presented. The first group consisted of healthy males and females 20–33 years of age; the second group was consisted of females with nonpathological pregnancy. Levels of proto- and coporphyrins in erythrocytes and copro- and uroporphyrins in urine are investigated. A reliable (P<0.03) increase in the protoporphyrin concentration in erythrocytes of pregnant females compared to the first control group is found. The average protoporphyrin levels in the first and second groups are 344±18 and 488±20 μg/liter, respectively. Coporphyrin levels in these groups differ insignificantly. Coporphyrin excretion from the organism of pregnant females has shown a tendency to increase for pregnancy terms of up to eight weeks and decrease for long terms (more than 32 weeks). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 633–636, September–October, 1997.     

Interpretation of the soret band of porphyrins based on the polarization spectrum of N-methyltetraphenylporphin fluorescence

Low-temperature (77 K) absorption, fluorescence, and fluorescence-excitation spectra and the fluorescence polarization spectrum for N-methyl-meso-tetraphenylporphin (N-methyl-TPP) are measured. Based on the polarization spectrum the absorption spectrum in the visible region (a “generic” porphyrin spectrum) is interpreted. In particular, it is shown that the fifth absorption band (the “Longo band”) that manifests itself in some porphyrins is a Q_y(0–2) band and does not belong to the individual electron transition. Emphasis is placed on the region of the Soret band. It is inferred that at least two allowed electron transitions (G →B_x and G→B_y) polarized mutually perpendicularly manifect themselves in this region. The interpretation of the Soret band of porphyrins [2] that attributes this band to one electron transition G→B_x is thereby rejected. This interpretation is confirmed by computer modeling of the polarization spectrum. Special features of the experimental polarization spectrum are explained by a more developed vibrational structure and, possibly, a larger half-width of the B_x band than the half-width of the B_y band. The contribution of the states of intramolecular charge transfer to the formation of the Soret band is discussed. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 65–72, January–February, 1999.     

银纳米颗粒对四苯基卟啉Q带荧光寿命的延长

文章报道了吸附在银纳米颗粒表面的四苯基卟啉(TPP)的Q带荧光寿命的变化.实验发现将银纳米颗粒的表面等离激元共振吸收峰调至与TPP的Q吸收带共振时,会使TPP的Q带荧光寿命得到延长.这是由于银纳米颗粒对表面的光电场有较大的表面等离激元共振增强效应,而处于激发态的TPP分子有较高的极性,这种增强的光电场会对有较高极性的TPP分子有稳定作用,所以延长了其Q带寿命.这对于以卟啉为光敏剂的光动力治疗有重要的意义.     

Effect of manganese stress on the mineral content of the leaves of wheat seedlings by use of X-ray fluorescence excited by synchrotron radiation

The present study describes the potential of the synchrotron radiation based X-ray fluorescence spectroscopy technique for the rapid, sensitive, user friendly and simultaneous monitoring of the changes in the elemental profile of the wheat seedlings stressed by excess manganese (Mn). For this, X-ray fluorescence spectra of the leaves of the control and Mn treated wheat seedlings have been recorded by synchrotron radiation X-ray of energy 15?keV. The analyses of the recorded spectra show the presence of elements chlorine, potassium, calcium, manganese, iron, copper, nickel, and zinc. A calibration-free approach, PyMca has been used for the quantitative estimation of the detected elements in the leaves of the control and Mn treated wheat seedlings. The excess supply of Mn to wheat seedlings results in the accumulation of manganese in the leaves of the seedlings. The accumulation of manganese in wheat seedlings negatively affects the uptake and translocation of calcium, potassium, and iron while it has stimulating effect on the uptake of copper and zinc.     

Theoretical studies on the one- and two-photon absorption properties of azulenylporphyrins and azulene-fused porphyrins

The electronic structures, one-photon absorption (OPA) and two-photon absorption (TPA) properties of the azulenylporphyrins and azulene-fused porphyrins have been comparatively studied by using DFT/B3LYP/6-31G(d) and the ZINDO/SDCI method. With the number of azulenyl groups increasing, the OPA wavelengths of all molecules are red-shifted in 400--600~nm and the two-photon absorption cross section is gradually enlarged. The azulene-fused structures facilitate an expanding conjugated area and increasing TPA cross section. The origin of TPA properties of studied compounds is studied with a two-level model. In summary, the azulene-fused porphyrins exhibit strong two-photon absorption.     

Effect of substituent groups of porphyrins on the electroluminescent properties of porphyrin‐doped OLED devices

Six tetraphenylporphyrins (TRPPH₂) with different horizontal substituents R (R = H, CH₃, OH, F, Cl, Br) were synthesized, and the organic light‐emitting diode (OLED) devices with a general configuration of ITO/TPD/Alq₃:2%TRPPH₂/Alq₃/Al were prepared. The substituted TRPPH₂ was used as the host dopant, 4,4‐bis‐(m‐tolyphenylamino)biphenyl (TPD) was used as a hole‐transporting material, and aluminum tris(8‐quinolinolato) (Alq₃) was used as an electron‐transporting material. The electroluminescent (EL) properties of these devices were studied to understand the light emitting properties of the substituted TRPPH₂. Previous studies have found that the color emitted by the devices was dependent on the TRPPH₂ dye concentration. The electronic effect of the horizontal substituents R of TRPPH₂ influenced the turn‐on voltage, brightness, and power efficiency of the devices. Also, the electroluminescence performance of the porphyrin‐doped OLED devices depended on the effectual overlaps between the emission of electron‐transporting material and the absorption of the dopants. This means that it is possible to evaluate the electroluminescence performance of the porphyrin‐doped OLED devices based on the emission of electron‐transporting material and the absorption of the dopants. Copyright © 2009 John Wiley & Sons, Ltd.     

Influence of low doses of gamma radiation on the ordering of Ni3Fe alloys

The results of electrical resistivity measurements taken over the course of time on the ordering of Ni₃Fe alloys after low-dose gamma irradiation are presented. A long-term, weak, aperiodic oscillation in the electrical resistivity of samples subjected to irradiation, and the absence of such oscillations in control samples was established. A change in the small-angle x-ray scattering after gamma ray irradiation of Ni₃Fe was observed.Tomsk Architectural and Civil Engineering Academy. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 89–92, September, 1993.     

Spectroscopic manifestations of the intramolecular hydrogen bond in ordinary and sterically hindered porphyrins

Spectroscopic manifestations of the intramolecular hydrogen bond (IHB) in ordinary and sterically hindered porphyrins were investigated by the methods of IR spectroscopy and molecular modeling. It is shown that the IHB plays a part in the formation of the νNH and γNH vibrations of porphyrins. By changing the type and value of the distortion of the macroring at the expense of steric effects of interaction of volumetric substituents, the parameters and spectroscopic manifestations of the IHB can be varied in a significantly larger range as compared with ordinary tetrapyrroles having nearly quadratic and planar macrorings. Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 522–527, July–August, 1999.     

侧链基团对聚合物薄膜瞬态发光性能的影响

采用飞秒激光光谱技术比较研究了两种卟啉侧链聚合物:卟啉丙烯酸酯-苯乙烯共聚物P[(por)A-S]和卟啉铁(Ⅲ)丙烯酸酯-苯乙烯共聚物P[(por)FeA-S]的瞬态发光性能。并采用纳秒激光光谱技术测量了小分子卟啉(TPP)的荧光动力学过程。结果表明:P[(por)FeA-S]具有比P[(por)A-S]快得多的荧光弛豫过程,而P[(por)A-S]的荧光寿命远小于小分子卟啉的荧光寿命。对上述过程进行了分析,P[(por)A-S]的荧光衰变主要来源于聚合物分子链间的相互作用;而P[(por)FeA-S]的荧光衰变除了来源于聚合物分子链间的相互作用外,中央金属离子与配位体之间的电荷转移也对卟啉发色基团的激发态超快无辐射弛豫具有重要的影响,对上述过程的产生机理进行了讨论。     

Effect of low-level radiation on the low temperature acoustic behavior of a-SiO2

We report on the mechanical behavior of an a-SiO2 84 kHz torsional oscillator operated between 100> or =T> or =1.0 mK. Below 10 mK we observed well-differentiated transient responses which we attribute to the interaction with low-level background radiation (gamma quanta and cosmic ray micro) and which can be modeled in terms of a change in the spring constant.     

荧光捕获效应对Yb3+磷酸盐玻璃光谱性质的影响

测试了不同掺杂浓度和不同厚度下Yb3+ 磷酸盐玻璃的吸收光谱、荧光光谱和荧光寿命 ,计算了积分吸收截面、吸收截面、受激发射截面、自发辐射寿命以及荧光有效线宽等光谱参数 ,讨论了荧光俘获效应对Yb3+ 磷酸盐玻璃光谱性质的影响 .结果表明荧光俘获效应随样品厚度和掺杂浓度的增加而增大 .由于荧光俘获效应的存在使得测量的Yb3+ 磷酸盐玻璃荧光寿命明显长于计算的荧光寿命 ,在 0 2mol%Yb2 O3低掺杂浓度下采用不同厚度 ( <4mm)的样品测量的荧光寿命之间误差为 3 0 %左右 ,高浓度 ( 6mol%Yb2 O3)掺杂下误差可达 43 % .荧光俘获还造成荧光谱线加宽 ,导致荧光有效线宽在低浓度 ( 0 2mol%Yb2 O3)时增加 14% ,在高掺杂浓度 ( 6mol%Yb2 O3)下增加 3 0 %以上     

Effect of irradiation at low doses and incubation of voids within the rate theory approach

The evolution of defects in a material under irradiation is studied at low doses (∼5 dpa or less) using rate equations. It is shown that as a function of temperature at a critical valueT _c a transition occurs in the behaviour of the solutions of the rate equations. BelowT _c the voids show incubation effects. An expression is derived for the critical dislocation density at which the void growth starts. This is related to the trapped vacancy fraction ε in vacancy dislocation loops. AboveT _c the incubation effects are shown to be related to the gas production rate which becomes the rate controlling parameter in determining the evolution of the defects. A gas-bubble to void transition occurs at a critical void radius and expressions are derived for the critical void size and dose at which the transition appears. It is shown that closely related to this is the incubation dose for interstitial loops. Finally, these features are corroborated by actual numerical integration of the rate equations.     

Influence of IR radiation on the carotenoid content in human skin

It is shown that the infrared irradiation decreases the content of β-carotene and lycopene carotenoids in human skin. A decrease in the content of β-carotene and lycopene may indicate that the IR radiation, as well as the UV radiation, is capable of forming free radicals in human skin. The investigations were performed in vivo using the technique of resonance Raman scattering developed by us for the noninvasive determination of antioxidant potential in skin.     

水稻叶绿素浓度对荧光光谱的影响

为了加强对水稻生长状况的监测,指导水稻的田间施肥,提高施肥利用效率,以增加农作物产量、提高粮食品质,实验室搭建了基于激光诱导荧光技术的荧光探测系统,以研究水稻叶片的叶绿素含量与荧光峰值比之间的相关性。文中测量样本为水稻分蘖期和拔节期的倒二叶,栽培地区位于中国江汉平原。文中先采用凯氏定氮法和相应公式结合测得水稻叶片的叶绿素含量(mg·g-1),再用搭建的荧光探测系统采集了水稻叶片不同叶绿素含量的荧光光谱(激发波长为355 nm)。获得了水稻叶片在不同叶绿素含量下的荧光光谱数据库,定量分析了荧光峰值比F₇₄₀/F₆₈₅(荧光谱峰740 nm、685 nm处的荧光强度比)与叶绿素含量的相关性,发现叶绿素含量的变化对荧光光谱特性影响明显。由实验数据分析可知荧光参数中的峰值比(F₇₄₀/F₆₈₅)与叶绿素含量呈现很好的线性正相关,相关系数(R2)在水稻的分蘖期和拔节期分别达到了0.901 3和0.912 5。实验分析结果表明诱导荧光光谱技术具有方便、快捷、无损等优点,在农作物生长状况的遥感定量监测等方面也具有一定发展潜力。     

荧光捕获效应对Yb3+磷酸盐玻璃光谱性质的影响

测试了不同掺杂浓度和不同厚度下Yb³⁺磷酸盐玻璃的吸收光谱、荧光光谱和荧 光寿命，计算了积分吸收截面、吸收截面、受激发射截面、自发辐射寿命以及荧光有效线宽等光谱参数，讨论了荧光俘获效应对Yb³⁺磷酸盐玻璃光谱性质的影响.结果表明荧光俘 获效应随样品厚度和掺杂浓度的增加而增大.由于荧光俘获效应的存在使得测量的Yb^{3+磷酸盐玻璃荧光寿命明显长于计算的荧光寿命，在0.2mol%Yb₂O₃低掺 杂浓度下 关键词： 荧光俘获 掺镱磷酸盐玻璃 荧光光谱}