Fast 1 H spectroscopic imaging using steady state free precession and spectral–spatial RF pulses

Recently, new methods for fast ¹H spectroscopic imaging based on the condition of steady state free precession (SSFP) were introduced to achieve a high signal-to-noise ratio at short minimum measurement times. In this work, a major improvement is presented to overcome a crucial drawback in some of the former sequences: the lack of spatial selectivity. Good spectral selectivity at very high sampling efficiency can be achieved by using spectral–spatial RF pulses, and combined with localised shimming. Results are shown from both phantom experiments and in vivo studies on the rat brain acquired at 4.7 T.Parts of this work were presented at ESMRMB 2004.     

玉米蛋白粉中黄体素、玉米黄素对乳腺癌细胞增殖的影响

研究玉米蛋白粉中黄体素、玉米黄素对乳腺癌细胞增殖的影响.体外培养MCF-7、SHZ细胞,培养时添加不同浓度的黄体素和玉米黄素,利用MTT法、HE染色法、扫描电镜等方法进行抗大鼠乳腺癌细胞增殖作用的研究.黄体素和玉米黄素对MCF-7细胞增殖的影响不显著,黄体素在体外对大鼠乳腺癌细胞的增殖效果也不明显,玉米黄素则在体外具有显著的抑制SHZ细胞增殖的作用.进一步研究表明:经玉米黄素作用的细胞在HE染色中,可见细胞核碎裂;扫描电镜可见细胞微绒毛消失,细胞膜表面呈现大量的凋亡小体.玉米蛋白粉中黄体素、玉米黄素对SHZ细胞生长的抑制作用具有较大的差异.     

超铀核素~(241)Am、~(239)PU、(237)Np 对大鼠肺部的致癌效应

本实验用维斯特种大鼠分别研究~(241)Am、~(239)Pu、~(237)Np 对肺部的致癌效应。中毒途径分肺穿刺、尾静脉和皮下注射三种。每公斤体重注入核素活度为0.2、1.0、5.0、8.5μCi。肺穿刺注入的动物在中毒后诱发肺癌往往经过肺泡和细支气管上皮局灶性增生——鳞状化生或腺瘤样增生—癌;而尾静脉或皮下注射的动物无此改变。每公斤体重注入活度为0.2、1.0、5.0μCi 的肺癌诱发率对~(241)A 癌组分别为10%、4.2—6.2%、6.0%,对~(239)Pu 组则分别为14.0%、6.3%及4.0%。~(237)Np组每公斤体重注入1.0μCi 的肺癌诱发率为13.0%。     

Comparison between the digestive behaviors of a new in vitro rat soft stomach model with that of the in vivo experimentation on living rats – Motility and morphological influences

A ‘near-real’ in vitro stomach model should not only resemble of the biochemical and physiological conditions found in the real stomachs, but also possess their geometrical and morphological details. In this work, quantitative evidences regarding the physiological relevant morphology including wrinkles on the inner-surface of a new rat model stomach, which assisted the compression and digestion behavior of the dynamics in vitro rat stomach (DIVRS), have been presented. A good repeatability in the tests on the DIVRS is shown, compared with the in vivo experiments of the living rats. However the digestion efficiency and the buffering capacity in the DIVRS were lower than the in vivo systems, most likely due to the limited motility mechanism of the movement of the model stomach system. Further improvements are needed to make the DIVRS more attractive for practical applications.