圆面紫外光源近距离辐照剂量的估算

本文介绍在紫外线功率计探头前加吸收膜的方法，测量血液辐射治疗仪紫外线灯在Ｚ＜３０ｃｍ处的辐照度，验证了“光量子疗法中圆面紫外灯辐照度的定量研究”［１］一文所导出的公式，在Ｚ＜３０ｃｍ仍成立。经计算分析，对公式进行了简化，并从简化公式的物理意义出发，给出了偏离轴线处的辐照计算公式。进而导出了辐照处血液辐照剂量的计算公式，最后用辛普森法估算出在Ｚ＝１ｃｍ处受照血液的照射剂量，从而解决了光量子疗法中圆面紫外灯辐照剂量的估算问题。为进一步研究吸收剂量及吸收剂量与疗效的关系等问题提供了依据。     

诊断剂量超声波对细胞增殖和抑制的实验研究

目前，产科诊中应用Ｂ超已成常规，但它的安全性引人关注。本研究采用模拟在人体中使用的实测超声剂量，对体外培养的Ｃ－９２９株细胞进行辐照，时间为１５分钟，通过细胞回复能力试验，观察了回复前（辐照后立即）及回复（辐照后９６小时）的细胞增殖与抑制。采用Ｃｓ－３超声诊断，分三档剂量进行实验。２＾＃剂量与人体应用进相近。结果１＾＃，２＾＃，３＾＃在回复前的细胞相对增殖率分别８７．５％，１０２．０％，１１５．４     

产科诊断剂量超声波对培养细胞影响的实验研究

采用模拟在人体中使用的实测超声剂量，对体外培养的Ｌ－９２９株细胞进行辐照，通过细胞回复能力试验，观察回复前后的细胞增殖与抑制。对体外培养的人胚肺纤维细胞经１次及５次辐照，观察了ＤＮＡ及细胞核面积的影响。并通过电镜观察了细胞超微结构的变化。上述实验结果，均提示经辐照后细胞有增殖趋向     

远红外辐射陶瓷纤维—X_1对人体血液流变学和血液动力学影响的研究

我们的前期研究发现，健康人穿着含有具有远红外线辐射功能的陶瓷纤维－Ｘ１的衣袖后，其穿着部位皮肤微循环血流量明显增加。为进一步研究此材料对人体循环系统的影响，本文通过双盲序贯实验观察了穿着含有国产软性陶瓷纤维－Ｘ１的衣物３０分钟对其血液流变学及血液动力学的作用。发现无论先后穿着含有Ｘ１的衣物，均未引起相应参数明显改变。说明Ｘ１辐射的远红外线只有促进浅表组织微循环的作用，而对血液流变性及血液动力学不产生明显影响。     

用计算机程序进行Hardy—Wenberg氏平衡吻合度测验的方法

本文给出计算机程序进行Ｈａｒｄｙ－Ｗｅｉｎｂｅｒｇ氏平衡吻合度的Ｘ＾２检验的方法和有关公式，同时给出在Ｘ＾２值和自由度ｎ给定的情况下，对概率Ｐ（Ｘ＾２，ｎ）进行精确计算的公式，这些方法和公式都已编成计算机程序，使得在进行Ｈａｒｄｙ－Ｗｅｉｎｂｅｒｇ氏平衡吻合度测验时，能够对数据进行了自动化的统计分析，大大地提高了工作效率。     

微波对TIL及其IL—2Rα表达影响的实验研究

应用２４５０ＭＨｚＣＷ微波，以不同剂量、不同时段辐照荷瘤鼠，观察微波对ＴＩＬ细胞及其亚群和ＩＬ－２Ｒα作用。结果发现：不同的微波辐照剂量，其对抗肿瘤免疫作用不尽相同。０．２ｍｗ·ｃｍ＾－２微波辐照，属非热效应的剂量，对抗肿瘤免疫无明显作用；２ｍｗ·ｃｍ＾－２微波辐照，可使抗肿瘤免疫滞后增强；２０ｍｗ·ｃｍ＾－２微波辐照，对肿瘤细胞具杀伤作用，但连续辐照８ｄ以上时，则出现抗肿瘤免疫的抑制，提示微波应     

微波对TIL及其IL－2Rα表达影响的实验研究

应用２４５０ＭＨｚＣＷ微波，以不同剂量、不同时段辐照荷瘤鼠，观察微波对ＴＩＬ细胞及其亚群和ＩＬ－２Ｒα作用。结果发现：不同的微波辐照剂量，其对抗肿瘤免疫作用不尽相同。０．２ｍｗ·ｃｍ－２微波辐照，属非热效应的剂量，对抗肿瘤免疫无明显作用；２ｍｗ·ｃｍ－２微波辐照，可使抗肿瘤免疫滞后增强；２０ｍｗ·ｃｍ－２微波辐照，对肿瘤细胞具杀伤作用，但连续辐照８ｄ以上时，则出现抗肿瘤免疫的抑制，提示微波应用于肿瘤治疗时，采用２０ｍｗ·ｃｍ－２微波定量辐照应少于８ｄ。     

血液灌流用日本球体活性炭的吸附性能

本文研究了目前国内临床应用的血液灌流吸附剂－－日本体活性炭的吸附性能，比较了包膜与未包膜的吸附效果，并与树脂吸附剂ＸＡＤ－４作了比较，此外还对吸附特性进行了理论探讨。     

热释光剂量测量在放射外科的应用

本文通过对仿真人体模Ｘ－刀照射剂量的测试，探讨热释光剂量测量在放射外科剂量设计中的应用价值。结果表明，热释光剂量测量法以高灵敏度的材料、小体积的测量元件、较多测点的设置，可得出比较精确的剂量分布结果，准确反映Ｘ－刀的剂量分布特征，对临床治疗有指导意义，是放射外科方便实用的剂量监测方法。本文尚就有关技术进行了讨论。     

辐射治疗能区内电子束剂量分布计算

本文给出了一个用计算辐射治疗能区内电子束剂量分布的解析算法，对电子束径向注量剖面的计算采用国际上流行的Ｆｅｒｍｉ－Ｅｙｇｅｓ理论，而电子束深度剂量分布的计算使用高能电子输运的双群模型，从而避免了传统的水等效深度方法所引入的系统误差。计算出的深度剂量分布和等剂量曲线与相应的实验测量数据作了比较，结果表明本文给出的方法可用于电子束辐射治疗计划系统的剂量计算。     

Use of a blood glucose meter for radiochromic film analysis in blood irradiation

The use of a diabetic blood glucose meter for radiochromic film dosimetry in blood irradiation using x-ray beams on a medical linear accelerator has been investigated. The glucose meter provides optical density analysis in the visible and infrared region using a reflectance measurement technique. By comparing the 'blood sugar' level output with standard calibration gafchromic films a calibration curve is produced for quantitative analysis. Results show that a reproducible dose to meter output curve can be fitted using a second order polynomial function and that blood irradiation doses in vitro were measured to within 7.9% mean error (as compared to ionization chamber results) using the blood glucose meter. This level of accuracy falls below that measured with a standard densitometer (4.3%); however, results show that the blood glucose meter, which would be available in any haematology department, produces an adequate measure of gafchromic film optical density for blood irradiation dosimetry.     

Radiation induced changes in the blood capillaries of rat duodenal villi: a corrosion cast, light and transmission electron microscopical study

Disturbances of gastrointestinal function are an important limiting factor in radiotherapy of the abdominal and pelvic regions. The pathogenesis of radiation induced intestinal dysfunction is not completely understood, although the intestinal mucosa has been shown to respond to irradiation by a progressive reduction in villous size. Since blood vessels in other organs have been implicated in the initiation of post-irradiation changes, the present study examines the response of villous blood vessels to an X-ray dose of 10 Gy after 3 days. Vascular corrosion casts and light and transmission electron microscopy (TEM) were used to study the post-irradiation vascular response. In control and sham-irradiated animals, the villous plexus was fountain-like: an arteriole entered the villous base and divided apically into two terminal branches. Villous capillaries apparently derived from the terminal branches, and united to form venules. In capillary loops the vertical inter-capillary distance was greater than the horizontal inter-capillary distance. After irradiation, the vessels became tortuous and the plexus was compressed apico-basally, shown by a decrease in the vertical inter-capillary distance. The capillary luminal diameter, as measured on resin semi-thin sections, was significantly increased. TEM showed that the endothelium was irregular and there was evidence of plasma leakage. These results suggest that villous damage seen after irradiation can include changes in the villous vasculature.     

A tandem calibration method for kerma-area product meters

For measurements of the kerma-area product (KAP) in diagnostic x-ray imaging, a method for calibrating field KAP meters with a reference KAP meter is presented. In this tandem calibration method, the field KAP chamber is positioned similarly as in measurements with patients. The reference KAP chamber is placed at a specified distance and used in the x-ray beam simultaneously with the field KAP chamber. The tandem method provides a feasible and practical way for calibrating field KAP meters of any type in their clinical position. Accurate measurements of the irradiation geometry are not required, but comprehensive calibration for the reference KAP meter is needed.     

两种布局后装机房辐射防护效果比较

目的:从理论和实验两方面考察不同布局的后装机房各监测点（电缆孔、控制台、防护门、候诊位）的周有效剂量,为改善职业人员辐射防护提供数据支持。 方法:依据射线强度衰减所遵从的平方反比定律及指数规律,推导出各监测点的周有效剂量计算公式,依次计算放射源处于不同位置时各监测点的周有效剂量;用MEDCOM射线检测仪测量后装机放射源活度最大时,放射源处于不同位置各监测点的空气比释动能率,计算周工作负荷,即可得各监测点的周有效剂量。 结果:考虑距离因素后,各监测点（电缆孔、控制台、防护门、候诊位）的周有效剂量理论值分别由13.00、30.90、0.012 10、1.200 μSv降至2.08、2.29、0.004 75、0.564 μSv;实验值则分别由4.32、25.60、2.01、1.96 μSv降至2.16、2.96、1.55、1.41 μSv。 结论:考虑距离因素的后装机房布局能显著降低职业人员的周有效剂量。     

数字X射线摄影机床边胸部摄影时周围散射线量测量

目的测量移动式数字X射线摄影（DR）机床边胸部摄影时照射野外的散射线辐射剂量。方法采用移动式DR机,用80kV、240mA、10ms和110cm焦-片距,垂直照射胸部体模,将测量仪分别放在360°均等分的8个角度、距照射野外1m和2m处,共测16个点。结果在0°和180°2m远距离处,测量仪上散射线量指示值最大,均为0.014μSv。在90°和270°2m远距离处最小,分别为0.011μSv和0.010μSv。结论一次移动式DR床边机胸部摄影,如患者和工作人员距照射野外2m远,其散射线辐射剂量低于人体7min所接受的自然本底照射剂量,不会产生危害后果。     

Flow sterilization of peritoneal dialysate by ultraviolet irradiation

Conclusions 1. A low-pressure mercury lamp can be used for the ultraviolet irradiation sterilization of transparent liquid media. 2. The design of a flow ultraviolet irradiation sterilization unit provides for conversion of the bulk flow into a thin layer, thus promoting efficient sterilization by using the full power of the radiation source and achieving good processing rates. 3. The useful power of the sterilization unit provides 163 times the lethal dose of bactericidal radiation for spores of microorganisms in transparent solution. 4. The method of flow ultraviolet irradiation sterilization is economical for treatments requiring the consumption of large volumes of solutions. 5. The optical density of water and aqueous solutions increases proportionally to the dose of irradiation at 254 nm. Department of Hemodialysis and Kidney Transplantation, Moldavian Republic Clinical Hospital, Kishinev. Scientific-Research Institute of Transplantation and Artificial Organs, Moscow. Translated from Meditsinskaya Tekhnika, No. 4, pp. 35–38, July–August, 1991.     

Determination of 50% endpoint titer using a simple formula

Two commonly used methods for calculating 50% endpoint using serial dilutions are Spearman-Karber method and Reed and Muench method. To understand/apply the above formulas, moderate statistical/mathematical skills are necessary. In this paper, a simple formula/method for calculating 50% endpoints has been proposed. The formula yields essentially similar results as those of the Spearman-Karber method. The formula has been rigorously evaluated with several samples.     

DNA strand breakage in normal and solar ultraviolet-sensitive ICR 2A frog cell lines exposed to solar ultraviolet wavelengths

ICR 2A frog cells and two solar ultraviolet (UV)-sensitive cell lines, DRP 36 and DRP 153, were irradiated with 150 kJ/m2 of the UV radiation produced by a fluorescent sun lamp, the radiation from which was passed through a sheet of 48A Mylar (DuPont, Wilmington, DE) to eliminate wavelengths shorter than approximately 315 nm. The irradiated cultures were also exposed to photoreactivating light (PRL), resulting in the removal of most of the pyrimidine dimers induced by the sun lamp UV irradiation, and then incubated 0-4 hr. At the end of the incubations, the cells were subjected to the alkaline elution assay. In these elutions, the cell lysates were either treated with proteinase K (proK) to eliminate any DNA-protein crosslinks (DPC) that may be present in the cells, or left untreated with proK. For the ICR 2A cells, the level of apparent DNA single-strand breaks (ssb) detected in elutions using proK increased with the incubation time after irradiation and remained high. However, when the DNA was eluted without proK pretreatment, the number of ssb fell rapidly. In contrast, the levels of ssb decreased in the DRP 36 and DRP 153 cells regardless of the use of proK in the elutions. Hence, this differential response in ssb induction may be indicative of a system involved with recovery following irradiation with solar UV wavelengths.     

全身放射治疗的剂量测量研究

目的:在全身放射治疗条件下,测量直线加速器空气中射线场均匀性,水模体内剂量分布情况,以及不同规格水模体的百分深度剂量值。方法:将加速器的源皮距(SSD)延长至450 cm,机架头旋转为90°,准直器开到最大,治疗头旋转为45°,形成菱形射野,使用剂量测量仪:PTW-UNIDOS,电离室:PTW 30001,测量Varian Clinac 2100C直线加速器的剂量值。结果与结论:加速器在空气中射线场剂量:T方向上总的平均值为5.147,绝对误差为5.8%,归一后相对误差达到;G方向上总的平均值为5.124,绝对误差为5.1%,归一后相对误差达到;此加速器的射线场均匀性可以用于全身放射治疗。水模体内剂量分布情况,在10 cm深度处,平均剂量值为8.960,归一数据中的绝对误差为;在20 cm深度处,平均剂量为6.381,从归一数据中的绝对误差为。     

Change in blood chemistry may explain higher toxicity of total body irradiation for bone marrow transplantation

Total body irradiation (TBI) is a well established conditioning regimen for patients who had undergone bone marrow transplantation. TBI not only offers a slightly significant survival advantage over Busulphan-based conditioning regimens but also lower toxicity profile. However the biological process after TBI seems rather different than conventional routine partial body irradiation. Not only the tolerance doses but also time to occurrence of the organ toxicities show a variation. It has been shown that there are alterations in trace element content in kidney after TBI in addition to cytokines and redox-active metal composition of blood. Acute phase proteins also have been shown to rise after irradiation. Considering all these evidences we suggest that TBI changes the blood content of trace elements, acute phase response proteins with probably many other inflammatory proteins and cytokines within the blood and this change in blood content may sensitize the organs to radiation.