毛竹茎秆纤维发育过程中Ca2+分布的时空变化

利用焦锑酸盐沉淀技术,对毛竹茎秆纤维发育过程中Ca^2＋的时空变化进行了研究。在纤维原始细胞发育期．Ca^2＋主要分布在细胞壁和细胞核染色质中;随着初生壁的形成,大量的Ca^2＋在液泡膜内侧成稀疏点状分布,在吞噬泡和降解的细胞质中出现Ca^2＋反应颗粒的沉积,液泡内逐渐出现大量的絮状Ca^2＋沉积,在细胞核和细胞壁上没有Ca^2＋分布;随后细胞质中Ca^2＋大量聚集,少量Ca^2＋沿液泡膜内侧分布,而液泡中Ca^2＋含量变得极少,在细胞壁、胞间连丝和细胞核中几乎没有Ca^2＋分布;随着次生壁的形成,胞质内的Ca^2＋浓度增加,并随着次生壁的逐渐加厚而聚集成块状;在次生壁形成的整个过程中,在降解的细胞质、凝聚的染色质、纹孔和运输小泡膜上一直存在Ca^2＋。结果表明：Ca^2＋参与了毛竹茎秆纤维细胞的增殖过程和细胞壁的整个形成过程;胞质Ca^2＋的内流是引起纤维细胞PCD的重要原因之一,并参与了PCD过程中原生质体的降解。     

利用膜片钳-激光扫描共聚焦显微镜同步实时系统观察心肌细胞浆内钙离子的释放

目的:采用膜片钳和激光扫描共聚焦显微镜同步实时系统观察心肌细胞钙离子的释放.方法:在体外培养的单个心室肌细胞上进行全细胞模式膜片钳技术和共聚焦显微镜钙成像技术相结合,同步实时记录钙火花和钙离子浓度变化.结果:在全细胞模式膜片钳记录心肌细胞膜钙电流的同时,激光扫描共聚焦显微镜可准确记录到胞浆内出现的钙火花.此技术有可能对于明确钙火花的特征.准确理解兴奋一收缩偶联的微观机制有重要意义.     

棉纤维发育过程中细胞壁果胶的免疫组织化学研究

利用半薄切片、扫描电子显微镜和免疫组织化学技术对陆地棉鲁7619品种不同发育时期胚珠表皮细胞进行了形态学观察和细胞壁果胶质的免疫荧光定位研究。结果表明,不同果胶组分在纤维发育的不同时期和不同位置具有不同的分布特点。高甲酯化的同型半乳糖醛酸聚糖广泛存在于不同发育时期的纤维细胞壁中,且在发育初期集中在细胞前端,而未甲酯化的同型半乳糖醛酸聚糖在不发育成纤维的表皮细胞中含量很低,在伸长的棉纤维细胞中大量分布。鼠李半乳糖醛酸聚糖Ⅰ在纤维发育初期几乎不存在,随着棉纤维伸长才有少量的积累,(1→5)-α-L-阿拉伯聚糖侧链则存在于纤维细胞壁中且含量较高。未甲酯化果胶可能影响细胞壁结构并促进棉纤维细胞伸长。     

Improvement of the cell performance in the ZnS/Cu(In,Ga)Se2 solar cells by the sputter deposition of a bilayer ZnO : Al film

ZnS is a candidate to replace CdS as the buffer layer in Cu(In,Ga)Se₂ (CIGS) solar cells for Cd‐free commercial product. However, the resistance of ZnS is too large, and the photoconductivity is too small. Therefore, the thickness of the ZnS should be as thin as possible. However, a CIGS solar cell with a very thin ZnS buffer layer is vulnerable to the sputtering power of the ZnO : Al window layer deposition because of plasma damage. To improve the efficiency of CIGS solar cells with a chemical‐bath‐deposited ZnS buffer layer, the effect of the plasma damage by the sputter deposition of the ZnO : Al window layer should be understood. We have found that the efficiency of a CIGS solar cell consistently decreases with an increase in the sputtering power for the ZnO : Al window layer deposition onto the ZnS buffer layer because of plasma damage. To protect the ZnS/CIGS interface, a bilayer ZnO : Al film was developed. It consists of a 50‐nm‐thick ZnO : Al plasma protection layer deposited at a sputtering power of 50 W and a 100‐nm‐thick ZnO : Al conducting layer deposited at a sputtering power of 200 W. The introduction of a 50‐nm‐thick ZnO : Al layer deposited at 50 W prevented plasma damage by sputtering, resulting in a high open‐circuit voltage, a large fill factor, and shunt resistance. The ZnS/CIGS solar cell with the bilayer ZnO : Al film yielded a cell efficiency of 14.68%. Therefore, the application of bilayer ZnO : Al film to the window layer is suitable for CIGS solar cells with a ZnS buffer layer. Copyright © 2012 John Wiley & Sons, Ltd.