吸入239PuO2致癌危险度实验中的剂量计算

钚在肺中的初始沉积量,钚在呼吸道的代谢规律以及靶器官质量是吸入²³⁹PuO₂致癌危险度实验研究中器官剂量计算的三要素。本文作者提出了大鼠暇入²³⁹PuO₂后肺、肺门淋巴结剂量计算公式 。此公式因考虑到靶器官质量变化规律, 优于国外算法,使器官剂量估算更合理。     

238Pu磷酸三丁酯络合物吸入后的代谢

对受照后的核燃料萃取加工时,存在着~(238)Pu和磷酸三丁酯一起进入人体的危害.因此,有必要研究~(238)Pu磷酸三丁酯络合物吸入后早期的代谢和从体内排出的情况.成年Wistar雌鼠一次吸入~(238)Pu(NO_3)_4气溶胶(吸30～40分钟,对照组)或~(238)Pu磷酸三丁酯络合物气溶胶(吸50分钟,实验组),两者初始肺负荷分别为13和1.4kBq.吸入后至64天不同时间肺、血、骨、肝、肾中的钚含量及8天内的钚排泄量均以通用放射化学方法测定.结果表明,磷酸三丁酯(TBP)基本上没有改变~(238)Pu在体内的分布,钚依然优先滞留于骨胳并随着时间的推移更著.TBP对钚的排泄方式没有影响,钚仍主要由粪排出.TBP使钚的吸收率提高,因而显著加快钚在体内的沉积和排出速度,并使钚的吸     

吸入钚及钠混合氧化物气溶胶后用Ca-DTPA治疗

作者探讨了事故性钚钠混合气溶胶吸入病例的Ca-DTPA 治疗问题。动物实验资料表明钚钠混合氧化物气溶胶吸入后在前数周内由肺转移入血的量较单纯 PuO_2气溶胶高100倍。因此,作者设计了两个实验:1.比较 Ca-DTPA 对进入血流的枸橼酸钚复合物和可转移的钚钠混合氧化物的促排效应.     

大鼠吸入239PuO2在肺巨噬细胞内的代谢

为了解核素对靶细胞的剂量与效应的关系,本实验用成年雄性大鼠,日龄75～80日,体重180～225克,令大鼠吸带有钚浓度为9.2×10^-9～5.5×10⁸Ci/l的气溶胶。实验结果表明:大鼠吸入²³⁹PuO₂后40分钟,由肺可洗出钚的76%在肺巨噬细胞(PM)内,1天后可达96%。洗出细胞中PM吞噬钚的指数随动物初始肺沉积量增加而增加。本实验给出了吸钚后28天以内,肺钚滞留函数式和PM内钚滞留函数式。这些可作为估算肺与PM内剂量的参考。     

239PuO2在大鼠呼吸道中的沉积与廓清规律的观察

为了阐明PuO₂在大鼠呼吸道中沉积与廓清规律,提出肺及肺门淋巴结(TLN)剂量计算公式,供有关的剂量一效应研究参考。使160只大鼠吸入²³⁹PuO₂气溶胶(AMAD:1.4μm:og=1.8),然后于378天内分期分批活杀,测定肺、TLN、股骨的²³⁹Pu量。结果表明,PuO₂在大鼠肺泡中：的初始沉积率为24.9±7.2%.肺中PuO₂2的廓清规律呈二项指数函数,其80%和20%分别以122.7和373天的有效半排期廓清。随着肺中钚含量的不断减少,TLN中钚的蓄积量不断增加,两者呈一定的函数关系。从而推导出肺和TLN剂量计算公式。骨中含钚量很少。本文还斌肺中PuO₂向TLN转移的问雹进行了讨论。     

Zn-DTPA促排田鼠吸入的硝酸钚

作者探讨了摄入钚量超过ALI不多情况下,在污染后几天或几周开始治疗以降低肺吸入硝酸钚的最佳治疗方案。他们用田鼠作实验,使动物吸入或注入肺部硝酸钚溶液后,按不同治疗方案给予Zn—DTPA吸     

吸入~(238)Pu和~(239)Pu硝酸盐的对比评价〔俄〕

将雌性成熟大鼠放在动态室中,吸入pH1.0的~(238)Pu或~(239)Pu硝酸盐气溶胶30分钟,肺中沉积的放射性(30分钟内)相应为13和15.5kBq,动物(6只/次)在乙醚麻醉下截头处死,测定1,4,8,16,32,64天的肺、血、骨、肝、肾中的钚含量,在最初一周中,每天分析排泄物的钚含量.结果按一般统计学方法处理.结果表明,~(238)Pu比~(239)Pu更迅速地离开肺,肺     

切尔诺贝利核电站事故后布尔良斯基地区居民受土壤中沉积钚的辐照水平

利用土壤受几种钚同位素污染水平的测定值并按照钚的生态学规律及放射卫生标准算得的剂量换算系数,估算了~(238)Pu,~(239)Pu,~(240)Pu对布尔良斯基地区西部控制区居民和农业生产人员造成的剂量负担.在计算由沉积在土壤中的钚所致的有效当量剂量时,既算了由摄入途径受到的部分剂量,也算了由吸入"未扰动土地"和耕耘田地上再悬浮起来的钚所致的剂量,并按照钚的代谢和剂量学参数做了校正.结果表明,土壤中沉积的钚通过吸入途径对各     

吸入238Pu和239Pu硝酸盐的对比评价

将雌性成熟大鼠放在动态室中,吸入pH1.0的238Pu或239Pu硝酸盐气溶胶30分钟,肺中沉积的放射性(30分钟内)相应为13和15.5kBq,动物(6只/次)在乙醚麻醉下截头处死,测定1,4,8,16,32,64天的肺、血、骨、肝、肾中的钚含量,在最初一周中,每天分析排泄物的钚含量。     

大鼠吸入空气——氧化的~(239)PuO_2后癌的发生

二氧化钚是钚的一种化学形式,最类似于环境污染物。对狗吸入铈和钚的气溶胶的研究表明,化学上制备氧化物或低燃点(350℃)氧化物比高燃点(700℃或更高)制备的氧化物具有较短肺滞留时间,而且转移到肝脏和骨骼中的量较大。在此报告中,对大鼠吸入空气——氧化的(AO)~(239)PuO_2后的代谢和诱发癌变进行了检     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

The role of interventional radiology in trauma

Introduction Interventional Radiology has evolved into a specialty having enormous input into the care of the traumatized patient.In all hospitals,regardless of size,the Interventional Radiologist must consider their relationships with the trauma service in order to     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

Carbohydrate Supplementation during Exercise: Does It Help? How Much is Too Much?

KEY POINTS· Carbohydrate intake during exercise can delay the onset of fatigue and improve performance of prolonged exercise as well as exercise of shorter duration and greater intensity (e.g., continuous exercise lasting about 1h and intermittent high-intensity exercise), but the mechanisms by which performance is improved are different.     

Diagnóstico ecográfico del neumotórax

The ultrasonographic diagnosis of pneumothorax is based on the analysis of artifacts. It is possible to confirm or rule out pneumothorax by combining the following signs: lung sliding, the A and B lines, and the lung point. One fundamental advantage of lung ultrasonography is its easy access in any critical situation, especially in patients in the intensive care unit. For this reason, chest ultrasonography can be used as an alternative to plain-film X-rays and computed tomography in critical patients and in patients with normal plain films in whom pneumothorax is strongly suspected, as well as to evaluate the extent of the pneumothorax and monitor its evolution.     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

磁共振DWI和动态增强鉴别颅底脊索瘤和侵袭性垂体瘤的应用

目的 探讨磁共振扩散加权成像(DWI)和动态增强在颅底脊索瘤和侵袭性垂体瘤(IPA)鉴别诊断中的应用价值.方法 搜集经手术病理证实且影像学有鞍区破坏的颅底脊索瘤患者15例、向鼻咽部侵犯的IPA患者20例.测量二者的表观扩散系数(ADC)值,绘制受试者工作特征曲线(ROC),分析动态增强曲线的类型,统计达峰时间(TTP)、增强峰值(EP)和最大对比增强率(MCER),分析各个参数在鉴别诊断中的价值.结果 颅底脊索瘤的ADC值为(1.274±0.07)×10-3mm2/s,高于IPA ADC值(0.672±0.03) ×10-3 mm2/s(P ＜0.001),ADC阈值为0.964×10-3mm2/s时,ROC曲线下面积为0.997,敏感度为93.3％,特异度为100％.颅底脊索瘤时间-信号强度曲线(TIC)Ⅰ型14例,TICⅢ型1例,此例TICⅢ型者TTP约40 s;IPA TIC Ⅰ型7例,TICⅢ型13例.颅底脊索瘤和IPA的EP、MCER差异均有统计学意义(P ＜0.001).结论 ADC值和TIC的类型及其相关参数(EP,MCER)有助于颅底脊索瘤和IPA之间的鉴别.     

Treatment of intrahepatic arteriovenous fistula in hepatocellular carcinoma with N-butyl-2-cyanoacrylate

Primary hepatocellular carcinoma (HCC) continues to be one of the most common malignancies with an incidence of approximately one million cases per year and a dismal prognosis; some authors have reported a median survival of 1 ～ 2 months after diagnosis. Although surgery remains the only hope for cure, few patients are candidates[1,2].