CHARACTERISTICS OF THE PRIMARY REACTION OF HYPOCRELLIN A PHOTOSENSITIZATION

The primary reaction of photosensitization of Hypocrellin A (HA) has been studied byusing techniques of ESR, spin-trapping and spin-counteraction. The experiments show thatHA is able to generate not only ~1O_2,but also O_2~-·OH and HA~- which are observed for thefirst time. The conversion of generating active oxygen into generating nonoxygen free rad-ical is confirmed as well. Based on the characteristics of the primary reaction which gene-rates these active substances (transient products), it is proposed that the photosensitized dam-age for the biological system by HA is probably related to not only ~1O_2 itself, but also amultiple effect from ~1O_2 as well as O_2~-,·OH and HA~+ free radical.     

高能质子辐射作用的分子机理——DNA空间结构微观损伤的Raman光谱特征

高能质子是空间辐射的重要类型。本文用激光Raman光谱技术,研究了高能质子(27.9 MeV)对水溶液中DNA辐射作用的分子机理。通过解析其特征Raman谱线,获得DNA空间结构微观损伤的以下信息:(1)维系双螺旋结构的碱基间氢键部分断裂;(2)4种碱基均被损伤,其中腺嘌呤环的破坏最重;(3)脱氧核糖发生了明显的变化;(4)骨架磷酸离子(PO_2~-)和磷酸二酯(PO_2)的损伤严重,并出现单、双链的断裂;(5)B型构象的数量显著减少。     

定点堵水用触变凝胶研发及性能评价

为解决油田开发过程中割缝筛管完井的水平井定点封堵问题,研发了一种适用于60～80℃油藏的水平井环空化学封隔材料Annular Chemical Paker(ACP),并针对其触变性、环空充填性能、持压强度、堵水率及降解性能等进行了评价.研究表明:改性聚多糖+丙烯酰胺(AM)单体+引发剂过硫酸铵+交联剂N'N-亚甲基双丙...     

A STUDY OF DYNAMIC DEVELOPMENT IN RADIOLESION AND CELL DEATH OF EUKARYOTES AFTER EXPOSURE TO IONIZING RADIATION——THE VISUALIZATION OF THE DYNAMIC REACTION BY MEANS OF CYTOCHEMICAL METHOD WITH LACTATE DEHYDROGENASE (LDH) AS NUCLEAR MARKER AND THE RADIAT

The present work deals with the radiation effect on adult rats suffering from acute, whole-body irradiation with cobalt-60 gamma rays of dosages 100R and 300R respectively. The morphological alteration of the lymphocytic nucleus and exhibition of eytochemical reaction of LDH in intra- or extra-nuclear region has been observed at the end of predetermined time intervals after irradiation. A close relationship between the percentage of damage of the lymphocytic nucleus and that of positivity of LDH reaction is seen from their variations with time parallel.From technical color microphotographs which exhibit cytochemical reactions, the existence of enzyme LDH in the nucleus so far obscure has been visually recognized. The events happening in enzymic reaction and the leakage of enzyme across the nuclear envelope reflect the dynamic nature. The ultrastructural alteration of nuclear anomalization confirms the dynamic development of inducing radiolesion. The experimental facts inspire us to attempt an explanatio     

电离辐射致真核细胞损伤与死亡的动态研究——乳酸脱氢酶(LDH)反应直观指示胞核损伤与异型化的动力学过程

本文用光学镜细胞化学方法与电子显微镜技术,用100R或300R~(60)Co γ射线对大白鼠进行一次全身照射,照射后以不同时间对淋巴细胞核形态及LDH反应的观察。其结果,细胞核破损率和LDH从胞核中以不同形式泄逸的反应率,在时相曲线上表现出平行关系的规律性。细胞化学彩色照片直观地揭示了LDH在淋巴细胞核中的存在。酶反应在胞核内的行为和向外泄逸的现象反映了淋巴细胞核受电离辐射后,内含酶发生动态反应。而细胞核异型化的亚显微结构变化,验证了动态发展过程。我们以动力学概念对辐射致胞核损伤与死亡的原发过程提出解说。     

Molecular Mechanism of High Energy Proton Radiation——Raman Spectroscopic Character of Microcosmic Damage in the Space Structure of DNA

High energy proton is an important type of the space radiation. The paper investigates the radiatione ffect of high energy proton (27.9 MeV) on DNA aqueous solution in the field of the molecular mechanism. The following information about the microcosmic damage to the space structure of DNA was obtained: (ⅰ) breakage of a part of interbase hydrogen bonds which maintained double helical structure of DNA; (ⅱ) damage on four bases, in which the damage on adenine ring was the most serious; (ⅲ) obvious change of deoxyribose; (ⅳ) serious damage on backbone phosphate ion (PO_2~-) and phosphate diester (PO_2) and the occurrence of scissions of double-stranded and single-stranded DNAs; (ⅴ) obvious decrease in the amount of B-form conformation.     

竹红菌甲素光敏作用原初反应的特征

为了从光生物方面判别竹红菌甲素(Hypocrellin A)的光敏作用,本文用电子自旋共振(ESR)、自旋捕捉和消自旋等方法,探讨了HA光敏作用原初反应的特征。不仅观测到它产生~1O_2的作用,还首次观察到(?),·OH和(?)的产生,并且证实,活性氧产生可转变为非氧自由基生成。根据产生这些活性物质(瞬态产物)的原初反应特征,可能表明,竹红菌甲素对生物系统的光敏损伤机制,不只包括~1O_2的作用,而且尚与(?),·OH和非氧自由基的多重作用有关。