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101.
采用电磁动态注射成型机塑化聚丙烯(PP)与纳米CaCO_3的共混料。通过扫描电子显微镜观察以及差示扫描量热法分析,探讨了振动参数对注射机预塑过程中分散效应的影响。实验发现,随着振动频率和振幅的增加,纳米CaCO_3在PP熔体中分散得更均匀,平均粒径逐渐减小;混合料的熔点向高温移动,混合质量得以改善,有利于完善结晶。因而表明,引入振动力场有效地促进了CaCO_3的分散,提高了注塑机的塑化效果。  相似文献   
102.
讨论了LPG贮罐发生泄漏事故时采取的注水堵漏工艺。  相似文献   
103.
Metallurgical and Materials Transactions B - The cationic effect of ferrous ions on the sulfide capacity of CaO-FetO-Al2O3-SiO2 slags was studied from the viewpoint of the ionic structure in the...  相似文献   
104.
Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA.  相似文献   
105.
The spatiotemporal evolution of hairpin vortex structures in a fully developed turbulent boundary layer is investigated qualitatively and quantitatively by usin...  相似文献   
106.
In the process of two-pass micro plasma arc welding of titanium alloy sheet,based on the thermal contact resistance theory,a three-dimensional transient heat tr...  相似文献   
107.
108.
Due to its essential role in cellular processes, actin is a common target for bacterial toxins. One such toxin, TccC3, is an effector domain of the ABC-toxin produced by entomopathogenic bacteria of Photorhabdus spp. Unlike other actin-targeting toxins, TccC3 uniquely ADP-ribosylates actin at Thr-148, resulting in the formation of actin aggregates and inhibition of phagocytosis. It has been shown that the fully modified F-actin is resistant to depolymerization by cofilin and gelsolin, but their effects on partially modified actin were not explored. We found that only F-actin unprotected by tropomyosin is the physiological TccC3 substrate. Yet, ADP-ribosylated G-actin can be produced upon cofilin-accelerated F-actin depolymerization, which was only mildly inhibited in partially modified actin. The affinity of TccC3-ADP-ribosylated G-actin for profilin and thymosin-β4 was weakened moderately but sufficiently to potentiate spontaneous polymerization in their presence. Interestingly, the Arp2/3-mediated nucleation was also potentiated by T148-ADP-ribosylation. Notably, even partially modified actin showed reduced bundling by plastins and α-actinin. In agreement with the role of these and other tandem calponin-homology domain actin organizers in the assembly of the cortical actin network, TccC3 induced intense membrane blebbing in cultured cells. Overall, our data suggest that TccC3 imposes a complex action on the cytoskeleton by affecting F-actin nucleation, recycling, and interaction with actin-binding proteins involved in the integration of actin filaments with each other and cellular elements.  相似文献   
109.
对现行高等数学教学中存在的一些突出问题,提出改革措施.  相似文献   
110.
通过在小型垂直气固两相流实验台上进行的实验研究,获得了4个独立灵敏区中微波传感器阵列信号在管截面上的灵敏度分布情况,并通过优化扩展计算,得到了可用于微波层析成像技术的灵敏度分布矩阵。  相似文献   
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