慢性应激对大鼠空间学习记忆及海马和前脑皮层突触体膜流动性的影响

慢性应激对学习记忆功能的影响是神经科学的热点问题,在脑内,海马和前额叶是与学习记忆功能密切相关的重要脑区,也是应激易累及损伤的主要靶区。膜流动性的改变在神经细胞功能活动中起重要作用。为探讨慢性应激对大鼠空间学习记忆功能的影响及前脑皮层和海马突触体膜流动性的作用。采用多因素慢性应激动物模型,通过开场试验和Morris水迷宫测试大鼠行为及空间学习记忆能力;并且测定大鼠前脑皮层和海马突触体膜流动性和突触体内游离Ca2+浓度的变化。研究结果显示,与对照组相比,应激组大鼠在应激后即刻,在新异环境中的自发活动和探究行为显著降低(p<0.05,p<0.01),空间学习记忆能力明显下降(p<0.05,p<0.01);并且应激组大鼠前脑皮层和海马突触体膜流动性显著降低(p<0.05,p<0.01);而突触体内游离Ca2+浓度的显著增加(p<0.05,p<0.01)。停止应激后一周,应激大鼠的各项指标有所恢复,但仍未达到正常水平。研究结果提示,慢性应激引起大鼠明显的开场行为改变和空间学习记忆功能障碍,这些变化可能与突触体膜流动性和突触体内游离Ca2+浓度的变化密切相关。

中国橙腹长吻松鼠种下分类的探讨

中国西南部的橙腹长吻松鼠应分为四个亚种。西藏东南部米什米山区、察隅和云南西北部高黎贡山一带的D.l.Subflavientris应为一有效亚种; 西藏南部聂拉木等地的橙腹长吻松鼠D.l. nielamuensis为新亚种, 它们有头骨小、体色浅等特点; 西藏南部雅鲁藏布江大拐弯以西的墨脱亚种D.l. motuoensis也为有效亚种; 南亚亚种D.l. garonum亦应有效。图1表5参9

Separation and purification of ovulation-inducing factors in the seminal plasma of the Bactrian camel (Camelus bactrianus)

Ovulation in the Bactrian camel depends upon ovulation-inducing factors in the seminal plasma. The present study was conducted to isolate and purify the bioactive fractions from the seminal plasma of these camels. The seminal plasma was fractionated by anion-exchange chromatography, and six fractions were obtained. The bioactive potential of each fraction was estimated from its effect on rat pituitary tissue cultured in vitro and by the effect of an intramuscular injection of the fraction into female camels in vivo. Both the third fraction (F3) and the fifth fraction (F5) stimulated the release of LH in vitro and in vivo. In addition, female camels ovulated within 48 h after intramuscular injection of F3. However, neither F3 nor F5 had any significant effect on the secretion of FSH, either in vitro or in vivo. When F3 was further fractionated into four subfractions, the third subfraction (F3-3) still stimulated the in vitro release of LH, but not of FSH. An attempt to further purify the ovulation-inducing factors in F3-3 failed owing to the similarity of the molecular characters.

Effects of initial soil fabric and mode of shearing on quasi-steady state line for monotonic undrained behavior

The effects of initial soil fabric and mode of shearing on quasi-steady state line in void ratiostress space are studied by employing the Distinct Element Method numerical analysis. The results show that the initial soil fabric and the mode of shearing have a profound effect on the location of the quasi-steady state line. The evolution of the soil fabric during the course of undrained shearing shows that the specimens with different initial soil fabrics reach quasi-steady state at various soil fabric conditions. At quasi-steady state, the soil fabric has a significant adjustment to change its behavior from contractive to dilative. As the stress state approaches the steady state, the soil fabrics of different initial conditions become similar. The numerical analysis results are compared qualitatively with the published experimental data and the effects of specimen reconstitution methods and mode of shearing found in the experimental studies canbe systematically explained by the numerical analysis. © 2009 Taylor & Francis Group.

Multiple color reflection in a single unit cell using double-layer electrochromic reaction

Multiple color states have been realized in single unit cell using double electrochromic (EC) reaction. The precise control of bistability in EC compounds which can maintain several colors on the two separated electrodes allows this new type of pixel to be realized. The specific electrical driving gives a way to maintain both sides in the reduced EC states and this colors overlapping in the vertical view direction can achieve the black state. The four color states (G, B, W, BK) in one cell/pixel can make a valuable progress to achieve a high quality color devices such like electronic paper, outdoor billboard, smart window and flexible display using external light source. © 2012 Optical Society of America.

葛洲坝产卵场中华鲟繁殖群体数量与繁殖规模估算及其变动趋势分析

采用声学探测的方法,进行中华鲟(Acipenser sinensis)繁殖群体数量的估算。2005～2007年,第1次产卵前的资源量分别为235尾、217尾和203尾;第1次产卵后的资源量分别为157尾、157尾和102尾。采用食卵鱼解剖统计和股分析的方法对中华鲟的自然繁殖规模进行估算,其结果为,2005～2007年间中华鲟的产卵量分别为356万粒、119.6万粒和238.6万粒。结合历史相关研究数据,对近10年的中华鲟繁殖群体数量和繁殖规模的变动趋势进行分析,结果显示,在20世纪90年代中期,第1次产卵