^235U,^147Pm,^153Sm单独及混合照射时对骨肉瘤细胞的增殖抑制作用

本研究运用四氮唑（ＭＴＴ）显色反应,观察了＾２３５Ｕ,＾１４７Ｐｍ,＾１５３Ｓｍ单独及混合照射骨肉瘤细胞时,对瘤细胞增殖抑制作用的程度比较,结果表明,各核素单独照射（照射用放射性活度为：＾２３５Ｕ,１２８．４Ｂｑ;＾１４７Ｐｍ,７．４×１０＾５Ｂｑ;＾１５３Ｓｍ,７．４×１０＾５Ｂｑ）及混合照射（＾２３５Ｕ＋＾１４７Ｐｍ,＾２３５Ｕ＋＾１５３Ｓｍ,＾１４７Ｐｍ＋＾１５３Ｓｍ,其放射性活度均为各自单     

Studies on apoptosis in bone tumor cells induced by 153Sm

The apoptosis in human bone tumor cells induced by internal irradiation with ^153Sm was studied. The morphological changes in bone tumor cells were observed by electronic and fluorescent microscopy, as well as DNA agarose gel eletrophoresis. DNA chain fragmentation, microautoradiographic tracing and the inhibition rate of proliferation in bone tumor cells exposed to ^153Srn with different duration time were examined. It was demonstrated that the bone tumor cells exposed to ^153Sm displayed nuclear fragmentation, pyknosis, margination of condensed chromatin, and formation of membrane bounded apoptotic bodies, whereas the percentage of DNA chain fragmentation of bone tumor cells increases in direct proportion to the duration of irradiation with ^153Sm, as well as DNA ladder formation in apoptotic cells. Also a marked inhibition effect of proliferation in bone tumor cells after exposure with ^153Sm was observed.     

亲和素-生物素系统的153Sm标记及其生物学分布动力学的研究

选用＾１５３Ｓｍ对生物素进行放射性标记,然后利用亲和素和链霉亲和素与生物素的高亲合力特性,再对亲和素和链霉亲和素进行＾１５３Ｓｍ的标记,观察到大鼠和小鼠体内的血清除率和生物学分布,并与＾１５３ＳｍＣｌ３和＾１５３Ｓｍ－ＤＴＰＡ的生物学分布进行比较。结果表明,＾１５３Ｓｍ标记的亲和素血素除迅速,肝肾放射性摄取高;＾１５３Ｓｍ标记的链霉亲和素血清除缓慢,肝、脾、肾等脏器和血液中滞留量高;而＾１５３Ｓｍ     

放射自显影示踪研究153Sm-EDTMP进入骨肉瘤细胞的动态

采用微观放射自显影示踪法探讨了^153Sm-EDTMP在不同照射时间间隔进入骨肉瘤细胞的过程，及其在瘤细胞中的滞留动态。结果表明：^153Sm-EDTMP首先向骨肉瘤细胞呈新膜性积聚，随后透过骨肉瘤细胞膜，进入瘤细胞内；也可被瘤细胞吞噬进入细胞内，以吞噬小体形式沉积；在呈现凋亡形态的骨肉瘤细胞中，^153Sm-EDTMP可在膜包裹着的凋亡小体中呈现。因此，^153Sm-EDTMP内照射进入骨肉瘤时所诱发的瘤细胞凋亡，是^153Sm-EDTMP能透入瘤细胞膜，以及被瘤细胞吞噬进入瘤细胞中沉积所致。     

Microstructural development of Zn–40Al alloy during aging

Abstract

The microstructure development of a Zn–40 wt-%Al alloy during aging was studied using transmission electron microscopy and electron diffraction. The supersaturated solid solution α′_s phase was formed after solution quenching treatment, which exhibited a substructure with a structure factor contrast in some areas after aging for shorter times at ambient temperature. Electron diffraction results show that there are satellite reflections in the 〈110〉 _α′s direction. The α′_sphase decomposes during aging, forming an (α+η) lamellar structure by the discontinuous reaction or cellular decomposition and an equiaxed fine grained structure by the continuous reaction, which are α″_m and α″ or α′_m and α′ with twin relationships to each other. A very fine tweedlike structure was observed to spinodally decompose ahead of the cellular zone. The value of the modulation wavelength λ is about 70–85 nm. The bowing and migration of the grain boundary would occur in the evolution of the discontinuous precipitates. Precipitate free zones of the vacancy denuded type were found in the vicinity of the grain boundary and within grains. It has been observed that the formation of the metastable R phase is always associated with dislocations.     

Pulsed laser surface treatment of magnesium alloy: Correlation between thermal model and experimental observations

The effect of deposition of Al + Al₂O₃ on MRI 153 M Mg alloy processed using a pulsed Nd:YAG laser is presented in this study. A composite coating with metallurgical joint to the substrate was formed. The microstructure and phase constituents were characterized and correlated with the thermal predictions. The laser scan speed had an effect on the average melt depth and the amount of retained and/or reconstituted alumina in the final coating. The coating consisted of alumina particles and highly refined dendrites formed due to the extremely high cooling rates (of the order of 10⁸ K/s). The microhardness of the coating was higher and several fold improvement of wear resistance compared to the substrate was observed for the coatings. These microstructural features and physical properties were correlated with the effects predicted by a thermal model.     

Resonance analysis of 151,153Eu from neutron capture cross section measurements in the energy range from 1 to 20 eV

The neutron capture cross sections of Europium-151 and Europium-153 have been measured by the time-of-flight method in the energy range from 0.005 to 100 eV using the Kyoto University Research Reactor Institute-Linear Accelerator (KURRI-LINAC). An assembly of Bismuth Germanate (BGO) scintillators was used to detect the prompt capture of γ rays. The absolute values of the neutron capture cross sections of ¹⁵¹Eu and ¹⁵³Eu were deduced by normalizing the thermal capture cross sections in JENDL-4.0 and ENDF/B-VII.1, respectively. Then, we have obtained the resonance parameters of 20 resonances in ¹⁵¹Eu and 17 resonances in ¹⁵³Eu using the code SAMMY.

For the 3.36-eV resonance of ¹⁵¹Eu, the evaluated resonance peak area in JENDL-4.0 is about 95% smaller than the present result. For the 7.00-, 7.22-, and 7.42-eV resonance; we confirmed that there are significant differences between the measured peaks and evaluated peaks in JENDL-4.0, ENDF/B-VII.1, and JEFF-3.2. For the ¹⁵³Eu, the evaluated resonance peak areas in JENDL-4.0, ENDF/B-VII.1, and JEFF-3.2 are about 15% larger than the measured resonance peak areas at the 2.46-, 3.29-, and 3.94-eV resonances.     

Thixomolded AZ91D and MRI153M magnesium alloys and their enhanced corrosion resistance

AZ91D and MRI153M alloys were produced by thixomolding. Their corrosion resistance is significantly higher than that of similar materials produced by ingot or die-casting. A corrosion rate smaller than 0.2 mm/year in 5 wt% NaCl solution is measured for the thixomolded AZ91D alloy. The corrosion behaviour was evaluated using immersion tests, electrochemical impedance spectroscopy, hydrogen evolution, glow discharge optical emission spectroscopy, and atomic emission spectroelectrochemistry. A bimodal microstructure is observed for both alloys, with the presence of coarse primary α-Mg grains, fine secondary α-Mg grains, β-phase, and other phases with a minor volume fraction. The amount of coarse primary α-Mg is significantly higher for the AZ91D compared with the MRI153M. The network of β-phase around the fine secondary α-Mg grains is better established in the thixomolded AZ91D alloy. A combination of several factors such as the ratio of primary to secondary α-Mg grains, localised corrosion or barrier effect due to other phases, as well as regions of preferential dissolution of the α-Mg due to chemical segregation, are thought to be responsible for the high corrosion resistance exhibited by the thixomolded AZ91D and MRI153M.     

亲和素-生物素系统预定位放免治疗的实验研究

选用^153Sm标记抗CEA单抗（McAb）和螯合DPTA生物素（DB2）,利用生物素化单抗－亲和素－^153Sm-DB2的三步法在荷人结肠癌裸鼠模型中进行预定位放免治疗。以^153Sm-CEAMcAb、^153Sm-mIgG、^153Sm-DB2作为治疗对照组,100μL生理盐水作为非治疗对照组,在移植瘤接种后的第3天实施治疗,采用单次较大剂量治疗（11．1MBq/每鼠）,定期测量裸鼠的体重、血白细胞计数和肿瘤生长体积以及瘤块的组织病理学检查,观察肿瘤抑制效应及毒副作用。结果表明,预定位放免治疗与直接标记单抗放免治疗对肿瘤有明显的抑制作用,治疗第5周肿瘤抑制率分别达到80．67％和78．44％,组织病理学结果提示肿瘤组织呈坏死样改变,而正常脏器如肝、肾等未见损伤;治疗前后白细胞计数以^153Sm-CEA McAb及^153sM-mIgG两组降低最为显著。提示预定位放免治疗具有低毒高效的治疗作用,较^153Sm-CEA McAb具有更大的安全性。     

153Sm配合物与牛血清白蛋白结合对骨摄取的影响

研究了NTMP（次氮三亚甲基膦酸），HEDTMP（N－（羟乙基）乙二胺基三亚甲基膦酸），DCTMP（1，2－环己二胺四亚甲基膦酸），EDTMP（乙基二胺基四亚甲基膦酸），DTPMP（二乙基三胺基五亚甲膦酸），DTPA（二乙基三胺基五醋酸）的^153Sm配合物在羟基磷灰石（HA）和I型骨胶原上的吸附及其在小鼠体内的骨摄取，观察到体内骨摄取与体外骨模型吸附性能的差别。在对上述6个^153Sm配合物与牛血清白蛋白（BSA）的结合性质研究中观察到，^153Sm配合物与BSA的结合性对其骨摄取过程有重要影响，并解释了^153Sm配合物体内骨摄取与体外骨模型吸附不一致的原因。