导管室内平板探测器CT定量评估兔肝肿瘤血管生成研究

目的 探讨导管室内平板探测器CT(FDCT)技术定量评估肝肿瘤血管生成的可行性.方法 25只新西兰大白兔VX2肝肿瘤模型构建后行FDCT检查,重建肿瘤血容量(BV)灌注图,分别检测肝肿瘤和肝实质BV值.FDCT检查后处死所有实验兔,取相应部位肝肿瘤标本检测微血管密度(MVD)和血管内皮细胞生长因子(VEGF)表达,分析肝肿瘤BV值与MVD和VEGF表达的关系.结果 25只实验兔中22只兔(88％)成功完成FDCT检查,BV灌注图均清晰显示肝组织和肿瘤,肝肿瘤表现为高灌注环伴低灌注中心的环状强化模式.肿瘤BV值与MVD和VEGF分级均存在良好相关性(P值均＜0.05),MVD与VEGF分级呈正相关(r=0.504,P＜0.001).结论 导管室内FDCT检查可定量评估肝肿瘤血管生成情况,可能有助于肝肿瘤介入诊疗.     

In-situ hydrogen in metal determination using a minimum neutron source strength and exposure time

Water is frequently present in the environment and is a source of hydrogen that can interact with many materials. Because of its small atomic size, a hydrogen atom can easily diffuse into a host metal, and though the metal may appear unchanged for a time, the metal will eventually abruptly lose its strength and ductility. Thus, measuring the hydrogen content in metals is important in many fields, such as in the nuclear industry, in automotive and aircraft fabrication, and particularly, in offshore oil and gas fields. It has been demonstrated that the use of nuclear methods to measure the hydrogen content in metals can achieve sensitivity levels on the order of parts per million. However, the use of nuclear methods in the field has not been conducted for two reasons. The first reason is due to exposure limitations. The second reason is due to the hi-tech instruments required for better accuracy. In this work, a new method using a low-strength portable neutron source is explored in conjunction with detectors based on plastic nuclear detection films. The following are the in-situ requirements: simplicity in setup, high reliability, minimal exposure dose, and acceptable accuracy at an acceptable cost. A computer model of the experimental setup is used to reproduce the results of a proof-of-concept experiment and to predict the sensitivity levels under optimised experimental conditions.     

Natural radioactivity in lignite samples from open pit mines “Kolubara”, Serbia – risk assessment

Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and ⁴⁰K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines “Kolubara” and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation.     

Detection of fast neutrons from shielded nuclear materials using a semiconductor alpha detector

The response of a semiconductor alpha detector to fast (>1 MeV) neutrons was investigated by using measurements and simulations. A polyethylene converter was placed in front of the detector to register recoil protons generated by elastic collisions between neutrons and hydrogen nuclei of the converter. The developed prototype equipment was tested with shielded radiation sources. The low background of the detector and insensitivity to high-energy gamma rays above 1 MeV are advantages when the detection of neutron-emitting nuclear materials is of importance. In the case of a ²⁵²Cf neutron spectrum, the intrinsic efficiency of fast neutron detection was determined to be 2.5×10⁻⁴, whereas three-fold greater efficiency was obtained for a ²⁴¹AmBe neutron spectrum.     

建立HPLC-纳米铜网版印刷电极-电化学检测器测定透析液中葡萄糖含量的方法

目的建立快速测定透析液中葡萄糖含量的方法。方法应用高效液相-电化学检测器和纳米铜网版印刷电极流动注射分析法测定微透析技术取样所得透析液中葡萄糖含量。结果该法测定的葡萄糖标准曲线的相关系数r=0.9995。葡萄糖日内测定的变异系数CV为4%～7%。测得大鼠纹状体透析液中葡萄糖的含量为(2.4±0.8)mmol·L-1。表明方法可靠。结论HPLC-纳米铜网版印刷电极-电化学检测器在测定透析液中葡萄糖有一定的应用价值。     

骨肉瘤侵袭范围的MRI测量与确定合理切除平面的相关研究

目的 探讨MRI判断肢体骨肉瘤局部侵袭范围的准确性及据此确定保肢术中的安全切除平面。方法 冷冻后的骨肉瘤截肢标本19例，按照MRI确定的相应层面，在断层切片机上切取厚度为0＋5cm的水平断层切片，肉眼测量肿瘤的软组织侵袭范围，并以0．5cm的间隔做连续病理切片，确定显微镜下肿瘤软组织侵袭范围。然后按照MRI确定的相应层面，纵向剖开标本，测量肿瘤的髓内肉眼范围，并以0．5cm的间隔做连续病理切片，确定显微镜下肿瘤的髓内侵袭范围。分别将肿瘤X线、MRI的侵袭范围与肉眼范围和病理侵袭范围进行统计学比较。结果 （1）X线、MRI、肉眼和病理测量的骨肉瘤髓内侵袭范围分别为（11.18±8.64）cm、（15.37±9．73）cm、（14.77±9.38）cm、（14．58±9.51）cm，经统计学分析MRI所确定的髓内侵袭范围与病理侵袭范围之间无显著性差异（P〉0．05）。（2）MRI、肉眼和病理测量的骨肉瘤软组织侵袭范围分别为：横径（6．62±2．23）cm、（6.22±2．21）cm、（6．23±2.38）cm；纵径（7.15±2.37）cm，（6．57±1.80）cm、（6.58±1.94）cm，经统计学分析MRI所确定的软组织侵袭范围与病理侵袭范围之间无显著性差异（P〉0.05）。MRI对骨肉瘤髓内和软组织的测量值均不超过病理范围10mm。结论 在确定骨肉瘤手术切除安全界面上，MRI较X线片有更高的准确性。以MRI为依据，在瘤体外2～3cm处截骨，软组织外1．0～1.5cm作为切除界面是安全可靠的。     

数字X线机（DR）的质量控制与保证

文章在对DR系统拟定测试项目并对DR拍片机进行定期测试和整理分析结果的基础上,总结出一套使DR系统高效、可靠、稳定运行,获取高质量数字图像的质量控制与保证计划。     

Use of gamma-spectrometry for simultaneous determination of 210Pb, 73As, 109Cd, 203Hg and 59Fe distribution and excretion in rats at low doses

γ-Spectrometry permits the identification and quantification of different γ-isotopes in the same aliquot. To estimate the sensitivity and discriminative power of a comparably small and inexpensive 8% germanium detector, we determined the detection limits for simultaneously applied ²¹⁰Pb, ⁷³As, ¹⁰⁹Cd, ²⁰³Hg and ⁵⁹Fe. The concentration of Fe and of each of the four potential environmental contaminants was determined in aliquots from all organs and tissues 10 days after simultaneous i.v. administration (2 μmol/kg body weight) to adult and growing iron-deficient and iron-adequate rats. Relating these values to the total size of each organ permitted to derive a whole body distribution pattern for all five isotopes in each individual animal. Cumulative renal and faecal excretion values were determined during the 10 day distribution period to calculate the half-lives for both excretory pathways for all five isotopes simultaneously. Distribution and excretion values corresponded well to literature data. Extrapolation of the results showed that the detector would be sensitive enough to discriminate and quantify the five metals at human dietary exposure levels. The results recommend to use γ-spectrometry to investigate kinetic aspects of interactions between toxic and essential trace metals, because the method reduces the number of required animals drastically.     

Spätergebnisse nach transduodenaler Sphincterotomie und Sphincterplastik aufgrund der Erfahrungen von 18 Jahren (unter besonderer Berücksichtigung der Analyse unbefriedigender Resultate)

Zusammenfassung Die Verfasser haben in 18 Jahren 289 transduodenale Sphincterotomien und 87 Sphincterplastiken durchgeführt (295 Patienten bei der ersten und 81 Patienten bei weiteren Gallenoperationen). Im unmittelbaren postoperativen Stadium verstarben 20 Patienten (5,3%), die Sektionsergebnisse zeigen jedoch, daß die Sphincteroperation lediglich für den Tod von 10 Patienten (2,6%) verantwortlich gemacht werden kann. Von den anderen 356 Patienten konnten wir nur 270 (75,8%) 1–11 Jahre postoperativ untersuchen. Das Spätergebnis ist in 89,6% ausgezeichnet bzw. gut. Zur Klärung der unbefriedigenden Ergebnisse wurden klinische, labormedizinische, radiologische und endoskopische Untersuchungen durchgeführt. Die unbefriedigenden Ergebnisse können in 6,6% auf bilio-pankreatische, in 0,7% auf extrabiliäre organische und in 1,5% auf nicht-organische Ursachen zurückgeführt werden. Die Bedeutung der endoskopischen Untersuchung zur Klärung der Gründe der unbefriedigenden Operationsergebnisse nach Sphincteroperationen wird hervorgehoben.

---

Late results of transduodenal sphincterotomy and sphincteroplasty based on 18 years of experience (with special respect to the analysis of unsatisfactory results)

Summary In the course of 18 years the authors performed transduodenal sphincterotomy on 289 and sphincteroplasty on 87 patients. The operations were connected, in 295 cases with prismary in 81 cases with repeated biliary surgery. Twenty of the patients (5.3%) died during the immediate postoperative period. However, on the grounds of autopsy data the death of only 10 patients (2.6%) can be attributed to the surgery of the sphincter. Out of the 356 surviving patients 270 were available for a follow-up study and were examined 1–11 years after the operation. Late results of the operation were found excellent or good in 89.6% of the patients. To clear up the unsatisfactory results clinical, laboratory, radiological, and endoscopic examinations were carried out. The unsatisfactory results can be explained by biliopancreatic (6.6%), organic extrabiliary (0.7%) and non-organic (1.5%) reasons. The authors emphasize the significance of endoscopic examinations following the surgery of the sphincter in the elucidation of the causes of unsatisfactory results.

     

A new bubble oxygenator (OCVC oxygenator): Development and clinical application

A new bubble oxygenator, designed for simple operation and clinical efficacy in intracardiac surgery, has been developed and clinically evaluated. This device is characterized by an oxygenating chamber with controllable blood-volume, integral heat exchanger and two-stage microfilter of gravity drainage system, an apparatus for creating and uniformly distributing oxygen bubbles, and construction materials of the device known to be minimally traumatic to the blood. Clinical experience in 132 infantile and pediatric open heart procedures has demonstrated its effectiveness as measured by embolic complications and simplicity in maintaining physiologic blood gas levels.