鸭胚B淋巴细胞中间纤维的研究

从26天北京鸭胚胎的腔上囊中分离B淋巴细胞。应用细胞选择性系列抽提方法与DGD包埋——去包埋剂的电镜制样技术相结合,显示出了B细胞的中间纤维的超微结构及分布特点:纤维致密交织呈网络状,其特点是均匀地遍布于整个胞质空间,纤维单丝直径在9—11nm。间接免疫荧光实验结果表明,B细胞的胞质对波形蛋白单抗呈阳性反应,且也显示出了波形纤维呈网络状的结构形式。本文采用单向电泳、双向电泳和蛋白质免疫印迹技术,证实了B细胞中间纤维波形蛋白的分子量约为55KD。     

Effect of TiO2@SiO2 nanoparticles on the mechanical and UV-resistance properties of polyphenylene sulfide fibers

In order to avoid the inherent photo-catalysis and aggregation of TiO2 in PPS, TiO2 nanoparticles were coated with SiO2 layers, which were chosen as the UV absorbent to improve the UV stability of polyphenylene sul fi de(PPS) fi ber. The PPS–TiO2@SiO2 nanocomposites fi bers were prepared via melt spinning, and the nanocomposites fi bers displayed different crystallization behaviors on variation of the diameters of TiO2@SiO2 nanoparticles, as con fi rmed by Differential Scanning Calorimetry(DSC). The spinnability, breaking strength and UV-resistance properties of PPS nanocomposites fi bers, as measured by homemade melt spinning machine, Xenon-lamp Weather Resistance Test Chamber and Yarn Tensile Tester, manifested the dependence on the diameters. The addition of nanoparticles with the diameter of 25 nm improved the spinnability and the mechanical performance of PPS most, which is attributed to the heterogeneous nucleation effect of nanoparticles. The UVresistance properties of the PPS nanocomposites were improved by the addition of TiO2@SiO2 nanoparticles. After aging for 180 h, PPS nanocomposites fi ber still maintained a high strength.     

Roles for microtubule and microfilament cytoskeletons in animal cell cytokinesis

Microtubule and microfilament cytoskeletons play key roles in the whole process of cytokinesis. Although a number of hypotheses have been proposed to elucidate the mechanism of cytokinesis by microtubule and actin flament cytoskeletons, many reports are conflicting. In our study,combining the cytoskeletons drug treatments with the time-lapse video technology, we retested the key roles of microtubule and actin filament in cytokinesis. The results showed that depolymerization of microtubules by Nocodazole after the initiation of furrowing would not inhibit the furrow ingression, but obviously decrease the stiffness of daughter cells. Depolymerizing actin filaments by Cytochalasin B before metaphase would inhibit the initiation of furrowing but not chromosome segregation, resulting in the formation of binucleate cells; however, depolymerizing actin fillaments during anaphase would prevent furrowing and lead to the regress of established furrow, also resulting in the formation of binucleate cells. Further, depolymerizing microtubules and actin filaments simultaneously after metaphase would cause the quick regress of the furrow and the formation of binudeate cells. From these results we propose that a successful cytokinesis requires functions and coordination of both the microtubule and actin filament cytoskeletons.Microtubule cytoskeleton may function in the positioning and initiation of cleavage furrow, and the actin filament cytoskeleton may play key roles in the initiation and ingression of the furrow.     

棉盖涤/锦超细旦复合丝针织运动面料的开发

阐述了利用涤／锦超细旦纤维在双面圆纬机上开发生产出的棉盖复合丝型的高档运动面料的编织工艺和染整工艺，着重介绍了芯吸高度和干燥剂两种试验方法，以及对该产品的导湿性能测试的结果与分析。     

Wax glands,wax production and the functional significance of wax use in three aphid species (Homoptera: Aphididae)

The structural details of wax glands and the physical form of the secreted wax is described for the apterae of three aphid species beech woolly aphid, spruce root aphid and woolly apple aphid. The glands are composed of greatly enlarged epidermal cells underlying a modified cuticle that forms distinctive wax gland plates. Secreted wax in the form of threads passes out of the cuticle as filaments, the arrangement of these filaments in the cuticle above each epidermal cell gives rise to the distinctive wax skein found in each species hollow, solid or honeycombed. It is suggested that the primary role of the secreted wax is to prevent the aphids becoming contaminated by their own secreted honeydew and that of other members of the colony. Other secondary roles considered include: individual microclimate isolation; protection from fungi, parasites and predators; waterproofing and frost protection.