多层CT探测器的发展

多层CT探测器的技术发展主要由两个方面组成。（1）性能更好的制作材料：由于稀土的良好特性,目前的CT探测器多采用此材料制作,临床优异效果已被证实;（2）不断进化的阵列：虽然近年来探测器宽度越来越大,但多层CT发展趋势是用更少排数的探测器获得更多层数的高分辨率图像。     

HEART RATE DERIVED FROM BLOOD PRESSURE AND OTHER PHYSIOLOGICAL SIGNALS

A device for providing a continuous on-line output of beat-by-beat HR in physiologic studies is described. The circuit eliminates the need for obtaining an EKG signal since it uses other vascular phenomena such as blood pressure, blood flow, or plethysmograph to produce an index of heart action to provide subsequent rate phenomena. Signal conditioning to produce the electrical analog of the vascular change is derived from either a pressure transducer, flow probe, plethysmograph, or other transducing device connected to the input of a Beckman-Offner, or Grass (Model 6) polygraph recorder. The output is in the form of a relay closure to provide initiating action to such devices as cardiotachometers, integrators, printers, counters, and many other instruments used in physiological studies.     

用反相高效液相色谱分析测定N—氧化利福平结晶的纯度

用μ-Bondapak C_(18)柱进行反相高效液相层析,50％甲醇水为移动相, 二极管阵列检测器于紫外254nm检测,可将N-氧化利福平与利福平分开。并通过三维紫外色谱图及等吸收度图证实N-氧化利福平为一单一物质。     

基于NaI (Tl) γ能谱温漂修正方法研究

目的 探究NaI (Tl) γ谱仪的道址随环境温度变化的规律,通过⁶⁰Co和¹⁵²Eu能谱修正试验验证修正方法的可靠性。方法 使用了2种稳谱方法,分别为曲线拟合的修正方法和已知测量峰值的修正方法。结果 温度变化会对NaI (Tl) 测量谱峰位产生影响,以25℃为参考温度, 在5℃时相对峰位会向右偏移9.6%,在60℃向左偏移16%。两种修正方法都是基于温度变化引起的道址变化进行的修正,修正后的测量谱与参考测量谱峰位基本符合,验证了修正方法的可靠性。结论 在现场监测时,为使测量谱信息准确可靠,建议对环境温度进行监控,以便进行相应的数据修正。     

AT1123型Χ-γ射线剂量检测仪终值响应时间的研究

目的 检测AT1123型Χ-γ射线剂量检测仪的终值响应时间,评估其对医用诊断X射线摄影机房放射防护检测的适用性。方法 医用诊断X射线摄影机在固定的管电压和管电流,曝光时间从10 ms递增至1000 ms,用AT1123型Χ-γ射线剂量检测仪测量不同曝光时间所对应的剂量率读数,当剂量率读数达到稳定最大值所需要的最短时间为该剂量检测仪的终值响应时间。结果 AT1123型Χ-γ射线剂量检测仪在4种辐射强度的X射线中,曝光时间为100 ms时,均能显示终值的93%以上;曝光时间为250 ms时,可以完全显示终值。结论 AT1123型Χ-γ射线剂量检测仪终值响应时间约为200~250 ms,适合应用于医用诊断X射线摄影机房的放射防护检测。     

Ermittlung der Wasser-Energiedosis nach der Sondenmethode gemäß DIN 6800 Teil 1: Vorschlag für eine Erweiterung der Grundgleichung

For any detector to be used for the determination of absorbed dose at the point of measurement in water a basic equation is required to convert the reading of the detector into absorbed dose in water. The German DIN 6800 part 1 provides a general formalism for that. A further differentiated formalism applicable to photon dosimetry is suggested in this work. This modified formalism presents the two following still general and at the same time fundamental properties of any dosimetry detector: a) a clear distinction of correction factors with respect to the physical processes involved during the measurement, and b) the fact that the process of energy absorption in the detector is determined by the spectral distribution of the fluence of the secondary charged particles. It is concluded that based on the modified formalism and knowing this spectral distribution within the detector a general method is available with benefits for ionization chambers as well as for any other dosimetry detector and which is applicable at reference as well as non-reference conditions without any preconditions.     

The physics of small megavoltage photon beam dosimetry

The increased interest during recent years in the use of small megavoltage photon beams in advanced radiotherapy techniques has led to the development of dosimetry recommendations by different national and international organizations. Their requirement of data suitable for the different clinical options available, regarding treatment units and dosimetry equipment, has generated a considerable amount of research by the scientific community during the last decade. The multiple publications in the field have led not only to the availability of new invaluable data, but have also contributed substantially to an improved understanding of the physics of their dosimetry. This work provides an overview of the most important aspects that govern the physics of small megavoltage photon beam dosimetry.     

多聚脱氧核糖核苷酸对面部毛孔粗大改善的临床观察

目的探讨多聚脱氧核糖核苷酸治疗前后面部毛孔粗大的改善情况,并进行定量分析.方法本研究于2019年共纳入14例志愿者,采用多聚脱氧核糖核苷酸PDRN治疗,使用VISIA—CR(Canfield Scientific Inc,Fairfield,NJ)皮肤检测仪采集数据,计算双侧面部毛孔数量值变化,比较求美者治疗前、治疗后差异有无统计学意义.结果VISIA数据分析显示治疗后毛孔计数低于治疗前,差异均有统计学意义(p<0.05).结论通过VISIA皮肤检测仪可以有效地监测治疗前后毛孔的客观数量变化,提示多聚脱氧核糖核苷酸治疗有助于改善皮肤浅表的毛孔粗大情况.     

移动DR乳腺摄影研究

目的:研究普通DR进行数字乳腺摄影可行性。方法:用佳能可移动DR板和国产乳腺钼靶X线机进行试验拍片对比。结果:制作的数字乳腺片质量较高。结论:普通DR板可用于高质量的数字乳腺片制作。