A COMMENT ON SPECTRAL TRANSMITTANCE IN MAMMALIAN SKELETAL MUSCLE

Spectral transmittance studies, related to photoradiation therapy light dosage, were carried out in vitro on mammalian skeletal muscle with expanded beam, broad band, white light (420-1100 nm). Spectra were collected by an EG&G 550/555 spectroradiometer with a 550-2A silicon detector. Bovine striated muscle imposes heavy absorption and distinct spectral structure, reflecting tissue absorption maxima at short wavelengths. Transmission above 650 nm is improved by a 10' factor, relative to blue light, in 1 cm of muscle. Half value layers were 0.82 mm in the 630 nm region, and were sensitive to tissue composition. Bovine muscle exhibited spectral effects related to the cadaver studies done by Wan et at. (1981b) but show singular differences, due primarily to complex tissue composition encountered in cadaver wall measurements, as contrasted with simple muscle. Spectral transmittance is a function of wavelength, tissue type and thickness.     

阻光染料对氯化银乳剂光谱增感的影响

增感染料在卤化银微晶上吸附并形成J-聚集体是染料光谱增感和超增感的关键步骤.本文利用紫外-可见吸收光谱研究了增感染料和阻光染料在氯化银微晶上的吸附,并考察了阻光染料对增感染料J-聚集体的形成及乳剂感光性能的影响.结果表明:不同阻光染料在氯化银微晶表面的吸附程度不同,对增感染料J-聚集体形成的影响也有差异.其中,吸附较小的不影响增感染料J-聚集体的形成,而吸附较大的阻碍增感染料J-聚集形成,特别是阻光染料在增感染料之前加入乳剂中时.在氯化银微晶上吸附很小的阻光染料基本不影响增感染料对乳剂的光谱增感,而吸附较强的阻光染料不仅吸收入射光,还抑制或破坏增感染料的光谱增感.因此,在氯化银微晶表面没有吸附的阻光染料才是优良的阻光染料.     

钙离子对卤化银乳剂化学增感和光谱增感的影响

本文通过控制乳剂中一系列不同的钙离子浓度(4.0～80×10^-3mol Ca²⁺/mol AgX),研究了化学增感时间对钙离子浓度的依赖性,测定了相应的感光特性,结果表明,乳剂中的钙离子在不影响最佳感光度的前提下,可有效地抑制灰雾并延缓化学增感过程,延长化学成熟时间。 经感红染料光谱增感后,测定了染料的相对增感倍率,本征及感红光谱感光度,研究了它们对轧剂中钙离子浓度的依赖关系。以卤化银乳剂对染料的吸附,对光的吸收以及Dember效应的实验结果为佐证,说明钙离子在光谱增感的电子转移过程中,起着电子陷阱的作用,从而抑制感红感光度的增感;与此同时,钙离子又抑制染料对本征感光度的减感,这可能是由于钙离子的存在阻碍了染料正空穴对卤化银本征潜影的氧化,从而保护了部分潜影免受染料正空穴的袭击。     

THE EFFECT OF SYSTEMIC CYCLOSPORIN A ON A HAIRLESS MOUSE MODEL OF PHOTOAGING

The mechanisms that cause skin wrinkling in response to chronic exposure to sunlight are unknown. We investigated the possibility that wrinkling of Skh-1 hairless mice is associated with an ultraviolet (UV) radiation-induced immunologic alteration. Exposing Skh-1 hairless mice to a regimen of nonerythemal UV-B (290-320 nm) radiation induced skin wrinkles after 6-7 weeks. Concomitant treatment with cyclosporin A decreased the time to the onset of wrinkles to approximately 4 weeks. Exposing HRS/J hairless mice or athymic nude mice to a similar nonerythemal UV-B radiation regimen for 10 weeks failed to induce skin wrinkles. Concomitant administration of cyclosporin A and UV-B radiation for 7 weeks to HRS/J hairless mice induced no skin wrinkles. Ultraviolet-B or UV-B plus cyclosporin A exposure caused increased immunohistochemical staining for Ia and F4/80 antigens in the upper dermis of tissue from Skh-1 mice, as compared to controls. Treating Skh-1 mice with UV-B radiation plus cyclosporin A was also associated with a large increase in the number of CD3+ cells in the dermis. These staining patterns were absent in similarly treated HRS/J hairless mice. Dermal mast cell numbers in Skh-1 mice were 2-3-fold higher than in HRS/J, athymic nude or NSA mice. Treatment with cyclosporin A increased Skh-1 dermal mast cell numbers approximately 2-fold but had no effect on the dermal mast cell numbers in HRS/J or NSA mice. Based on these findings we postulate that UV-B light and cyclosporin A exacerbate an immunological condition in Skh-1 mice, one consequence of which is manifested as skin wrinkles. Thus, the induction of skin wrinkles in this mouse strain may have no relevance to the wrinkles observed in human skin after chronic exposure to sunlight.     

ENVIRONMENTAL EFFECTS ON THE ELECTRONIC SPECTRAL PROPERTIES OF 1-PYRENECARBOXALDEHYDE AND THEIR APPLICATION IN PROBING BIOLOGICAL STRUCTURES

Abstract— The electronic spectra of 1-pyrenecarboxaldehyde are sensitive to environmental polarity. In the fluorescence spectrum especially, an extensive loss of structure, large red shifts and an increase in the quantum yield is progressively observed on going from aliphatic to polar solvents or even mixtures between the two types of solvent. When 1-pyrenecarboxaldehyde interacts with substances possessing an amino group its fluorescence quantum yield increases without a simultaneous spectral shift or loss of spectral structure. These phenomena are explained in terms of the effect of the solvent on the nπ *- ππ * state coupling. The effect of temperature and the pH on the electronic spectral properties are discussed. The solvent-sensitive photophysical properties of 1-pyrenecarboxaldehyde can be used to probe the interior of lecithin vesicles. These properties, as well as the dynamics of the interaction of the hydrocarbon with proteins, can yield information about mitochondrial membranes.     

PHOTOSENSITIZING EFFECTS OF 8-METHOXYPSORALEN ON THE SKIN OF HAIRLESS MICE—11. TRAIN AND SPECTRAL DIFFERENCES FOR TUMORIGENESIS

Abstract. –The absorption and fluorescence characteristics of subchloroplast particles highly enriched in P700 (1 P700 to 10–15 chlorophyll a molecules) and of two artificial systems are presented here. The fluorescence characteristics measured were excitation and emission spectra, and the degree of polarization of fluorescence. The model systems studied were chlorophyll a and pheophytin a in a polystyrene matrix, and a colloidal mixture of these two pigments with bovine serum albumin. Effects of 0.5% sodium dodecyl sulfate on the optical properties of the P700-enriched particles are also described. The importance of pigment-pigment and pigment-protein interactions in determining the fluorescence properties of these particles are discussed. The possible role of pheophytin in these preparations needs further investigation.     

可溶性镍酞菁的光谱特性研究

利用UV-Vis吸收光谱、荧光光谱及半经验ZINDO/S方法,研究了4种可溶性镍酞菁(FPcNi、MePcNi、iBPcNi、iPPcNi)的电子吸收光谱和荧光光谱.研究结果表明:随着取代基的供电子能力增加,酞菁的最大吸收波长(λ_max)和发射波长(λ_em)发生红移,摩尔消光系数变小;随着溶液浓度增大,酞菁聚集体浓度增大,λ_max发生蓝移,但浓度对λ_em影响较小,同时荧光相对强度随浓度增大,出现最大值;随着溶剂配合能力的增加,λ_max、λ_em都发生红移.     

光谱探针法研究膜模拟体系界面酸性的进展

简要介绍了利用光谱探针法研究膜模拟界面酸性的基本概念和基本原理,重点评述了这一方法的应用。     

两种不同光谱类型的R-藻红蛋白的荧光性质研究

红藻中的R-藻红蛋白(R-PE)依照其吸收光谱可分为两种不同的光谱类型,即“双峰型”和“三峰型”。本文通过对不同pH条件下的R-PE的荧光光谱及荧光寿命的研究,发现“三峰型”R-PE的pH稳定范围较“双峰型”R-PE大。在R-PE浓度对荧光光谱的影响实验中,随着蛋白浓度的增加,荧光峰位置逐渐红移。荧光寿命逐渐增大,荧光强度先行增加而后减弱。用碘离子对其荧光进行猝灭,随着碘离子浓度的增大,荧光强度逐渐降低,荧光寿命逐渐缩短,并服从Stem-Volmer规则。     

TRANSMITTANCE OF NONIONIZING RADIATION IN HUMAN TISSUES*

Abstract— Spectral transmittance of 400–865 nm radiation through various human structures, including the skull with scalp, the chest wall, abdominal wall and scrotum, is presented. There is essentially no visible light of wavelengths shorter than 500 nm transmitted through the chest or the abdominal wall. In contrast, 10^?5–10^?4 of blue light can reach the brain and testes. Transmittance of all tissues increases progressively with wavelength from 600 to 814nm. The maximal transmittances are 10^?2–10^?1 for skulls and scrota, and 10^?3–10^?2 for chest and abdominal walls. Tissue thickness, optical absorption and scattering are major influencing factors.     

菁染料薄膜的光谱性能及稳定性的研究

本文研究了6种长链菁染料薄膜的光谱特性与光稳定性,以及两种抗氧剂对其薄膜光稳定性的影响。研究表明,结构相近的菁染料利用旋涂法成膜后,光稳定性与其母核的结构有关,依吲哚>喹啉> 唑>噻唑>硒唑顺序而变,与溶液状态下相类似,两种抗氧剂均为有效的单重态氧猝灭剂,都能提高菁染料的光稳定性。且抗氧剂的用量对染料的稳定性也会产生一定的影响     

724型可见分光光度计100%透射比失调故障维修方法

针对724型可见分光度计100%透射比失调的故障-透射比无法调至100%，测量时100%透射比经常变化和100%透射比严重失调，分析了造成该类故障的原因，提出了排除该类故障的维修方法。     

用于透射比标定的高精度分光光度测量装置

本文主要介绍了所研制的高精度分光光度测量装置的结构、原理,讨论了非线性校正的方法,并对测量装置的误差进行了分析,最后与国内外同类装置进行了比较。     

PHOTOELECTRIC EFFECTS IN POLYETHYLENE—II.SPECTRAL STUDIES

Abstract— A semiclassical calculation of the ionisation potential of solid polyethylene yields a value of 4.5 eV.A dissolution technique is employed to study the absorption spectrum in the near U.V.The absorption contains both structural and impurity components but there is no edge near 4.5 eV.Neither absorption component is correlated with the carrier trap distribution suggested for the material.It is inferred that the photoconductivity is extrinsic.     

短波长菁染料对氯化银乳剂的光谱增感作用

本文利用紫外 可见吸收光谱、光谱曝光等手段研究了5种短波长菁染料,比较了它们在氯化银乳剂上的光谱增感作用,得出3种较好的短波长增感染料,并研究它们在氯化银颗粒上的吸附行为.结果表明,这3种染料在氯化银颗粒上均有吸附,并能有效地提高氯化银乳剂在短波长区的感光度.     

荧光素钠溶液的pH值对其激光及光谱特性的影响

本文研究了荧光素钠乙醇溶液的pH值对其激光能量转换效率以及吸收光谱、荧光光谱等特性的影响。通过对其吸收光谱的研究, 证明荧光素钠在乙醇溶液中存在多种互变异构体。在不同pH值的溶液中, 它们具有不同的浓度而处于酸碱平衡。各种异构体对λ=337.1 nm激发光的吸收截面σ_P和其荧光最子产额φ各不相同。随着pH值的增大, 溶液中双价阴离子的浓度逐渐增大。而双价阴离子的σ_P和φ值为最大。由于激光输出能量的大小与σ_P和φ直接有关, 因此, 荧光素钠溶液的激光能量转换效率也将随着pH值的增大而提高。