大光金鱼花不同叶位叶片超微弱发光的光子计数统计

采用生物超微弱发光探测技术,并用量子光学中的光子计数分布统计方法测量植物叶片超微弱发光的结果表明,大光金鱼花幼叶和老叶的超微弱发光强度较低,光子计数分布与泊松分布基本吻合。     

微弱发光分析技术应用实例(六)——发光分析与肿瘤研究

微弱发光分析技术已经用于肿瘤学研究,骨肿瘤病人和正常人的血液和尿液的发光强度使用BPCL型微弱发光测量仪进行了测量.结果指出,骨肿瘤病人血液和尿液的发光强度高于正常人（P＜0.05）.骨肿瘤病人尿液的发光强度在手术之后明显降低（P＜0.05）.裸鼠血液和各种脏器的微弱发光测量结果表明,荷瘤之后,各个脏器的发光强度显著增加.     

微弱发光分析技术应用实例(六)——发光分析与肿瘤研究

微弱发光分析技术已经用于肿瘤学研究,骨肿瘤病人和正常人的血液和尿液的发光强度使用ＢＰＣＬ型微弱发光测量仪进行了测量,结果指出,骨肿瘤病人血液和尿液的发光强度高于正常人（Ｐ〈０．０５）,骨肿瘤病人尿液的发光强度在手术之后明显降低（Ｐ〈０．０５）。裸鼠血液和各种脏器的微弱发光测量结果表明,荷瘤之后,各个脏器的发光强度显著增加。     

生物中的超微弱发光

超微弱发光是所有生物都具有的一种普遍现象,发光强度极其微弱,量子效率也很低,波长范围广,自１９２３年发现超微弱发光以来,各国科学家做了大量的研究,对机理进行探讨,目眼微弱发光的柚是依然不很清楚。生物超微弱发光在许多领域得到广泛的应用,由超微弱发光研究发展为的发光检测技术快速,简便,而且不会对组织材料造成损伤。本语文就生物超微弱发光机理及应用研究进行了综述。     

淡水鱼超微弱光子辐射的实验研究

采用一台高灵敏的生物活体单光计数系统对淡水鱼的主要超微弱发光特性进行了研究.淡水鱼的各种不同脏器的光子辐射强度数值为3.6—97.3CPS.发射光谱的最大值接近640nm处和460nm附近.实验结果表明,超微弱光子辐射的总强度随所测的时间而变化,加入UOUO_2~( )离子之后,其发光强度下降.     

绿豆芽超微弱发光的二维图像探测

采用微通道板像增强研制了一种能探测极弱光图像的超高灵敏度光电探测系统,能够探测到０．５Ｐｈｏｔｏｎｓ／ｍｍ２·ｓ（阴极灵敏度）的极弱发光图像,是目前弱光图像探测器中灵敏度最高的。应用上述的光电探测系统,进行了绿豆芽超微弱发光二维图像探测的研究,首次得到了以下结论：１．绿豆发芽时存在超微弱发光现象,发光强度在１０４－１０５Ｐｈｏｔｏｎｓ／ｓ·ｃｍ２的范围内;２．子叶和幼叶的发光高于幼茎的发光;３．在避先保持１０分钟豆芽发光衰减至稳定后,绿豆芽仍能维持一定的发光。上述结论为超微弱发光现象的生物学理论研究和医学及环境保护中的应用提供了实验依据。     

微弱发光分析技术原理及应用实例(一)

微弱发光分析技术近年得到迅速发展,在自由基、活性氧分析、化学发光分析、生物的超微弱发光分析、发光免疫分析、生物发光分析等领域得到广泛应用.简要介绍了微弱发光分析技术的测量原理,并以一些研究成果为实例讲解如何应用微弱发光分析技术进行研究和实践.     

生物大分子在血浆发光中的作用

血浆超滤后,其大分子浓缩部分的自发发光强度以及碱诱导发光强度都增高,而透过膜部分的自发发光强度以及碱诱导发光强度则降低。用１０％ＺｎＳＯ４沉淀除去部分蛋白质后的血浆制液,其发光强度下降。说明大分子,尤其是蛋白质在血浆超微弱发光中起着重要作用,结合蛋白质本身可能就是发光反应的底物。     

生物系统超弱发光的探测:绿豆、大鼠血液和3T3细胞的发光

本文报道一台用于生物系统微弱发光研究的高灵敏单光子计数系统、能在200—900nm范围测量生物样品的发光强度、光谱和发光动力学.由于光电倍增管以液氮冷却、噪声降至40cps,在99.9%置信度和6小时测量条件下,最小可探测0.3光子/秒、厘米~2的微弱光子流.用该系统研究了萌发绿豆、大鼠血液和体外培养正常和转化3T3细胞的发光.这些样品的发光都含有一个光诱导成份,且以不同的速率衰减、最后达到稳定水平代表了这些生物系统自发的代谢发光.实验发现,转化的3T3细胞的发光强度比正常细胞约低30%.     

人体超微弱发光图像中的信号检验

用近期研制的具有单光子探测能力的超高灵敏度成像系统获得了人体体表生物超微弱发光的强度数据。为分析图像中的信号检验,二项分布被用于人手不同时间累积发光图像中的信号显著性检验,证实人手存在超微弱生物发光,手指的发光强度在３００～５５０ｐｈｏｔｏｎｓ／ｓ范围内,全手的发光强度在８５０～１２００ｐｈｏｔｏｎｓ／ｓ范围内。     

电离辐射对活细胞超弱发光的影响

本文报导了活细胞(CHO和V_(79)细胞)的辐射诱导低水平发光.实验证明,这种诱导的超弱光子发射要比未受辐照的细胞发光要高,我们发现该诱导发光的强度依赖于照射剂量.辐射增敏剂miso(Misonidazole)可以增强活细胞的超弱光子发射.     

代谢抑制剂对萌发绿豆超弱发光的影响

本文报导了A.D(actinomycin D)、EB(ethidium bromide)、CHI(cycloheximide)及NaN_3,对萌发绿豆(胚根长1.5cm左右)的自发性超弱发光强度的影响的研究结果,提供了DNA分子和/或RNA合成代谢对超弱发光有贡献的证据.     

植物幼苗原发性超弱光子成像的研究

采用光子计数成像系统（PIAS）对植物幼苗萌发过程的超弱发光进行观察。结果表明,自发光子长时间积累可形成二维图象;光子计数和采集图象均可得到植物体的自发发光;通过实验探测到幼苗的根,叶在同一平面图象有不同的发光表现;光子成像系统可客观地比较生物自发超弱发光,为进一步研究超弱发光机理提供实验基础。     

人体体表超弱光发射的测量

研制了一种能在室温下正常工作的高灵敏度并具有极低暗计数的光子计数器。用它来研究人体体表超弱光的发射。测量结果表明：人体不同部位体表发光强度是很不一致的：手指发光最强、掌心次之、然后是面颊、前额、小臂、上臂、胸腹部等依次减弱。先照对体表的发光有很大影响。体表不同部位因光照引起发光强度的增加值差异很大;避光后先强的衰减速度也不同。体表的发光强度随体表温度的升高而增强。某些物质接触体表可以使体表发光强度发生很大变化。     

水稻种子萌发期超微弱光子计数成像研究

运用ＰＩＡＳ捕获了水稻种子萌发期自发辐射的超微弱光子。光子长时间累积形成了二维图像。研究表明：萌发种子整体均发光,胚根和胚芽及其生长点发较强的光;水稻种子萌发期光子辐射强度呈现双峰值规律,第二峰前期光子数和根生长长度与萌发时间均有自然对数关系,根生长激增迟后于光子数激增     

Discrimination between different types of low-level luminescence in mammalian cells: The biophysical radiation

Cellular low-level luminescence was measured after various disintegrative processes in brain cell preparations. In addition to known origins of low-level luminescence, e.g. oxygen radical reactions or enzymatic and non-enzymatic redox systems, a further source of photon emission is reported which is independent of external oxygen, oxygen radicals and enzyme activities. Vital cells from rat brain homogenates or pig oligodendrocytes could be kept for hours at 37 °C without any photon emission. Only after disintegrative processes a cellular photon emission could be induced. The maximal intensity of about 400 impulses/s/mg protein and a total radiation of about 6 × 10⁶ I/mg depended on the type of cells. The signal could be retained completely at 4 °C or in frozen samples. Heating (10 min, 90 °C) did not suppress the photon emission. Luminol and lucigenin did not amplify the signal as is usually observed in oxygen radical-producing cells. Non-specific radical scavengers as well as detergents suppressed the cellular photon emission completely. It is suggested that this cellular luminescence represents a biophysical radiation which originates from the interruption of an intermolecular radiationless energy transfer.     

On measuring biomembrane microviscosity using pyrene luminescence in aerobic conditions

The movement of pyrene in a lipid bilayer is shown to occur not only in the lateral but also transmembrane direction. Within the excited state lifetime, the pyrene monomer elevates from the depth to the polar region of the membrane and emits a luminescence photon. The excimer does not exhibit any marked transmembrane movement. The luminescence quenching efficiency of monomers and excimers depends on the depth of penetration of the quencher into the membrane. In the lipid bilayer, pyrene luminescence is strongly quenched by oxygen. The binding of pyrene to membrane proteins protects it from quenching. It has been concluded that the widely used estimations of membrane viscosity from pyrene luminescence intensity are incorrect.     

生物超微弱发光在猪肉新鲜度检测中的应用

为了寻找最佳测试条件来实现猪肉样品新鲜度的检测,采用单光子测试系统测试了不同条件下猪肉的自发辐射强度和延迟发光的变化。4天连续测试的噪声平均值为76.3 counts/s,平均偏差为1.1 counts/s;自发辐射测试中肥肉样品信号较强,其强度随放置时间的增加有增加过程;延迟发光测试中大排及肥肉信号较强;按照延迟发光动力学曲线拟合,拟合系数达0.996。随着测量时间的增加,延迟发光的特征时间t降低,反应了猪肉新鲜度下降。实验结果表明该系统能实现对生鲜猪肉新鲜度的直接检测,具有选材少,检测速度快的特点。     

THE TOTAL LUMINOUS EFFICIENCY OF LUMINOUS BACTERIA

Methods are described for measuring the light emitted by an emulsion of luminous bacteria of given thickness, and calculating the light emitted by a single bacterium, measuring 1.1 x 2.2 micra, provided there is no absorption of light in the emulsion. At the same time, the oxygen consumed by a single bacterium was measured by recording the time for the bacteria to use up .9 of the oxygen dissolved in sea water from air (20 per cent oxygen). The luminescence intensity does not diminish until the oxygen concentration falls below 2 per cent, when the luminescence diminishes rapidly. Above 2 per cent oxygen (when the oxygen dissolving in sea water from pure oxygen at 760 mm. Hg pressure = 100 per cent) the bacteria use equal amounts of oxygen in equal times, while below 2 per cent oxygen it seems very likely that rate of oxygen absorption is proportional to oxygen concentration. By measuring the time for a tube of luminous bacteria of known concentration saturated with air (20 per cent oxygen) to begin to darken (2 per cent oxygen) we can calculate the oxygen absorbed by one bacterium per second. The bacteria per cc. are counted on a blood counting slide or by a centrifugal method, after measuring the volume of a single bacterium (1.695 x 10^–12 cc.). Both methods gave results in good agreement with each other. The maximum value for the light from a single bacterium was 24 x 10^–14 lumens or 1.9 x 10^–14 candles. The maximum value for lumen-seconds per mg. of oxygen absorbed was 14. The average value for lumen-seconds per mg. O₂ was 9.25. The maximum values were selected in calculating the efficiency of light production, since some of the bacteria counted may not be producing light, although they may still be using oxygen. The "diet" of the bacteria was 60 per cent glycerol and 40 per cent peptone. To oxidize this mixture each mg. of oxygen would yield 3.38 gm. calories or 14.1 watts per second. 1 lumen per watt is therefore produced by a normal bacterium which emits 14 lumen-seconds per mg. O₂ absorbed. Since the maximum lumens per watt are 640, representing 100 per cent efficiency, the total luminous efficiency if .00156. As some of the oxygen is used in respiratory oxidation which may have nothing to do with luminescence, the luminescence efficiency must be higher than 1 lumen per watt. Experiments with KCN show that this substance may reduce the oxygen consumption to 1/20 of its former value while reducing the luminescence intensity only ¼. A partial separation of respiratory from luminescence oxidations is therefore effected by KCN, and our efficiency becomes 5 lumens per watt, or .0078. This is an over-all efficiency, based on the energy value of the "fuel" of the bacteria, regarded as a power plant for producing light. It compares very favorably with the 1.6 lumens per watt of a tungsten vacuum lamp or the 3.9 lumens per watt of a tungsten nitrogen lamp, if we correct the usual values for these illuminants, based on watts at the lamp terminals, for a 20 per cent efficiency of the power plant converting the energy of coal fuel into electric current. The specific luminous emission of the bacteria is 3.14 x 10^–6 lumens per cm². One bacterium absorbs 215,000 molecules of oxygen per second and emits 1,280 quanta of light at λ_max = 510µµ. If we suppose that a molecule of oxygen uniting with luminous material gives rise to the emission of 1 quantum of light energy, only 1/168 of the oxygen absorbed is used in luminescence. On this basis the efficiency becomes 168 lumens per watt or 26.2 per cent.