A simple model describes large individual differences in simultaneous colour contrast

We report experimental evidence for substantial individual differences in the susceptibility to simultaneous colour contrast. Interestingly, we found that not only the general amount of colour induction varies across observers, but also the general shape of the curves describing asymmetric matching data. A simple model based on von Kries adaptation and crispening describes the data rather well when we regard its free parameters as observer specific. We argue that the von Kries component reflects the action of a temporal adaptation mechanism, while the crispening component describes the action of the instantaneous, purely spatial mechanism most appropriately labeled simultaneous colour contrast. An interesting consequence of this view is that traditional ideas about the general characteristics of simultaneous contrast must be considered as misleading. According to Kirschmann’s 4th law, for instance, the simultaneous contrast effect should increase with increasing saturation of the surround, but crispening predicts the converse. Based on this reasoning, we offer a plausible explanation for the mixed evidence on the validity of Kirschmann’s 4th law. We also argue that simultaneous contrast, the crispening effect, Meyer’s effect and the gamut expansion effect are just different names for the same basic phenomenon.     

CO中毒致迟发性脑病大鼠脑内CD4+T淋巴细胞浸润及神经胶质酸性蛋白的表达

目的观察CO中毒致迟发性脑病（DNS）大鼠脑内CD4^＋T淋巴细胞浸润以及神经胶质酸性蛋白（GFAP）的表达情况，探讨CO中毒致DNS的病理过程。方法25只SD雄性大鼠随机分为对照组、染毒后3、7、10、20d组，每组5只。采用HE和免疫组织化学染色方法，观察染毒后各时间点大鼠脑内病理形态学变化，及CD4^＋T淋巴细胞浸润和GFAP的表达情况。结果HE染色结果显示：各染毒组在大脑皮层及海马均出现神经细胞不同程度的变性、坏死，染毒后7d组最重。免疫组织化学染色结果显示：对照组无CD4^＋T淋巴细胞浸润，有少量GFAP表达；各染毒组不同脑区CD4^＋T淋巴细胞、GFAP均有不同程度的浸润和表达。CD4^＋T淋巴细胞染毒后3d开始浸润，7d达峰值，两者在数量上差异有统计学意义（P〈0．01）。各组染毒后GFAP均有大量表达，随染毒时间延长表达数量呈上升趋势。结论CD4^＋T淋巴细胞可能参与了CO中毒致DNS的免疫病理过程，GFAP阳性细胞对CO中毒引发的DNS可能具有保护作用。     

大鼠癫痫持续状态后水通道蛋白-4的表达

目的 探讨癫痫持续状态（SE）后大鼠水通道蛋白-4（AQP4）的表达变化与脑水肿形成之间的关系。方法 54只SD大鼠随机分为对照组（n=6），SE后6h，12h，24h，48h，72h，96h，120h，168h组（n=6）。腹腔注射锂-匹罗卡品建立大鼠SE模型，免疫组织化学染色和逆转录PCR方法检测AQP4蛋白和基因在SE形成后的表达。结果 SE后AQV4蛋白和mRNA24h表达水平明显增加，48h达到高峰，持续72h后下降，168h时仍有表达。SE后AQP4表达变化和脑水肿形成过程在时间上呈明显的正相关（r=0．73，氏0．05）。结论 SE后AOP4表达明显增强，在时间上与脑水肿形成呈正相关，提示AQP4在SE后脑水肿形成过程中起着重要作用。     

肿瘤微环境对树突细胞功能状态的影响

目的：探讨肿瘤细胞分泌的可溶性细胞因子营造的微环境对树突细胞(DCs，dendritic cells)的分化发育的影响，以进一步揭示肿瘤的免疫逃逸机制。方法：用免疫磁珠从人外周血分离CD14^ 单核细胞，加入粒细胞巨噬细胞集落刺激因子(GM-CSF)、白细胞介素4(IL-4)和人白血病细胞Jurkat培养上清液体外培养DCs，以正常培养诱导的DCs作为对照，采用傅立叶变换红外光谱(FTIR)技术分析人白血病细胞培养上清液对DCs分化发育的影响。结果：正常培养DCs与肿瘤上清液培养的DCs相比，在细胞内蛋白质和核酸的相对含量和细胞内消耗葡萄糖重新合成磷脂的量方面差异无显著性，但是，在细胞的转录状态方面差异有显著性。结论：肿瘤细胞上清液培养液所营造的微环境细胞转录水平上对DCs的功能状态有明显的抑制作用。     

Expression of Na+/HCO3− co‐transporter proteins (NBCs) in rat and human skeletal muscle

Aim: Sodium/bicarbonate co‐transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. Methods and results: Western blotting of muscle homogenates and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate‐dependent transport. This indicates that the NBCs are preserved in the vesicles. The western blotting experiments demonstrated the existence of at least two NBC proteins in skeletal muscle. One NBC protein (approximately 150 kDa) seems to be related to the kidney/pancreas/heart isoform NBC1, whereas the other protein (approximately 200 kDa) is related to the NBC4 isoform. The two NBC proteins represent the electrogenic isoforms named NBCe1 and NBCe2. Membrane fractionation and immunofluorescence techniques confirmed that the two NBCs are located in the sarcolemmal membrane as well as in some internal membranes, probably the T‐tubules. The two NBCs localized in muscle have distinct fibre type distributions. Conclusions: Skeletal muscle possesses two variants of the sodium/bicarbonate co‐transporter (NBC) isoforms, which have been called NBCe1 and NBCe2.     

Accelerated 3D echo-planar spectroscopic imaging at 4 Tesla using modified blipped phase-encoding.

Whole-brain echo-planar spectroscopic imaging (EPSI) often substantially lengthens MRI/MRSI (magnetic resonance spectroscopic imaging) protocols. To halve acquisition time, application of a blipped phase-encoding (PE) gradient during the EPSI readout (RO) was previously suggested by PE of the even RO echoes in k-space at an interstitial location along k(PE), separated from the odd RO echoes, effectively reducing the number of PEs by a factor of 2. However, the approach is very susceptible to phase inconsistencies between even and odd RO echoes in the presence of B(0) inhomogeneities and gradient imbalance, leading to ghosting in the PE direction. In this work, the blipped PE gradient is placed in between pairs of even/odd RO gradient lobes to avoid these problems. This approach is demonstrated in a phantom and in normal human brain in vivo at 4T. While the proposed method allows substantial reduction in metabolite ghosting, it may be limited by the presence of a relatively large spurious signal at the Nyquist frequency.     

胰岛素和睾酮对Ishikawa细胞葡萄糖转运蛋白4表达的影响

目的探讨胰岛素(INS)和睾酮(T)对多囊卵巢综合征(PCOS)子宫内膜腺上皮细胞生长的影响和葡萄糖转运蛋白4(GLUT4)表达的调节机制。方法体外培养Ishikawa细胞,予不同浓度INS(90、60、30、3、0.3 U/L)或T(10-3、10-4、10-5、10-6、10-7mmol/ml)刺激Ishikawa细胞48 h,MTT法检测INS、T对Ishikawa细胞生长的作用;免疫细胞化学检测GLUT4蛋白在Ishikawa细胞定位表达;分别以30 U/L INS和10-5mmol/ml T刺激Ishikawa细胞24和48 h,逆转录聚合酶链反应(RT-PCR)方法测定INS和T对Ishikawa细胞GLUT4 mRNA表达的影响。结果(1)不同浓度的INS均可促进Ishikawa细胞的生长,随着INS浓度的增加,INS促进Ishikawa细胞生长作用越强,INS浓度自0.3~30 U/L时,Ishikawa细胞生长依次加强,与对照组相比均有显著性差异(P<0.01)。INS浓度达60、90 U/L时,细胞生长状况与INS浓度为30 U/L相似。不同浓度的T均可抑制Ishikawa细胞的生长,随着T浓度的增加,T抑制Ishikawa细胞生长作用越明显。T浓度自10-7、10-6、10-5mmol/ml,Ishikawa细胞生长依次减弱,与对照组相比均有显著性差异(P<0.01,P<0.05),T浓度达10-4、10-3mmol/ml时,细胞生长抑制状况与T浓度10-5mg/ml相似。(2)GLUT4蛋白,定位表达于Ishikawa细胞的细胞浆内。(3)Ishikawa细胞中GLUT4 mRNA表达,在INS组和T组均较对照组减弱(P<0.01,P<0.05),INS组比T组减弱更明显(P<0.05),且INS和T作用24和48 h GLUT4 mRNA表达无显著性差异(P>0.05)。结论不同浓度INS和T均可影响Ishikawa细胞生长,并降低GLUT4 mRNA的表达,推测PCOS高胰岛素、高雄激素血症的病理生理特性有可能影响子宫内膜的代谢过程,与子宫内膜的病变相关。     

一种基于μ子进行核材料探测成像的模拟系统

宇宙射线斗子成像检测技术具有穿透力强、对高Z材料敏感等特点，特别适合检测特殊核材料，是监控核材料走私的有效方式之一。在搭建μ子成像检测硬件系统的同时，我们开发了一套针对实际硬件系统的模拟系统，并利用该系统开展斗子成像方法的研究。本文将介绍该模拟系统的有关情况，并给出利用该系统得到的仿真结果。相信这一工作将对实际宇宙射线μ子成像系统的设计给出指导意见。     

4-1BB(CD137)配体在几种肿瘤细胞株上的表达

目的：研究4—1BBL在几种人肿瘤细胞株上的表达。方法：用RT—PCR及法检测肿瘤细胞内4—lBBL mRNA水平的表达；用流式细胞仪检测肿瘤细胞膜表面4—1BBL的表达。结果：4—1BBL在Jurkat细胞株上高表达(98．97％)，在HL-60和K562上表达较低(分别为24．77％和19．23％)，而在HL-29细胞株上基本不表达(2．13％)。结论：4—1BBL在不同肿瘤细胞株表达水平不同。     

弱精子症患者精子蛋白的初步研究

目的从蛋白质水平探讨弱精子症患者精子蛋白的改变,以期寻找精子活动力低下的原因。方法运用蛋白凝胶电泳技术分离90例特发性弱精子症患者和30例正常供精者精子标本的总蛋白质,结合免疫印迹技术鉴定差异蛋白,并对试验数据进行统计学分析。结果患者组与对照组精子蛋白表达量存在差异,且患者组中精子活力低下不同严重程度者的蛋白含量也存在差异(P<0.05),对于差异显著条带的Western Blotting分析显示差异蛋白为DDX4。结论精子活力与蛋白质差异表达有关,主要差异蛋白DDX4可作为评估精子活力的生物标志物。