http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Study of the Electric Field Screening Effect for Field Emitter Arrays
Nannan Li,Fei Yan,Shucai Pang,Lei Chen,Dazhi Jin,Wei Xiang,De Zhang,Jingyi Dai,Baoqing Zeng 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8
Understanding the influence of the interaction of emitters on the field emission performance of a field emitter array is of great importance for the design of a multi-emitter device. In this work, a screening factor S is defined to quantify the effect of electric field screening due to the interaction of emitters in an array. A three-dimensional finite integration technique is used to study the electric field screening effect for Spindt-type field emitter arrays which have potential applications in flatscreen displays and high-power vacuum electronics. The dependences of the electric field screening on the tip-to-tip spacing, half-angle of the emitter, height of the emitter and radius of the tip’s curvature are analyzed. The effects of the variations in the size of the emitter’s geometry on the most efficient arrangement to achieve maximum emission efficiency in an array are discussed.
Hong-Yan Zhao,Wei Liu,Yi Wang,Nannan Dai,Jian-Hong Gu,Yan Yuan,Xue-Zhong Liu,Jian-Chun Bian,Zong-Ping Liu 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.3
Exposure to cadmium (Cd) induces apoptosis in osteoblasts (OBs); however, little information is available regarding the specific mechanismsof Cd-induced primary rat OB apoptosis. In this study, Cd reduced cell viability, damaged cell membranes and induced apoptosis in OBs. We observed decreased mitochondrial transmembrane potentials, ultrastructure collapse, enhanced caspase-3 activity, and increasedconcentrations of cleaved PARP, cleaved caspase-9 and cleaved caspase-3 following Cd treatment. Cd also increased the phosphorylationof p38-mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK)1/2 and c-jun N-terminal kinase (JNK) in OBs. Pretreatment with the caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, ERK1/2 inhibitor (U0126), p38 inhibitor(SB203580) and JNK inhibitor (SP600125) abrogated Cd-induced cell apoptosis. Furthermore, Cd-treated OBs exhibited signs of oxidativestress protection, including increased antioxidant enzymes superoxide dismutase and glutathione reductase levels and decreased formationof reactive oxygen species. Taken together, the results of our study clarified that Cd has direct cytotoxic effects on OBs, which are mediatedby caspase- and MAPK pathways in Cd-induced apoptosis of OBs.
Di Hu,Hui Zou,Tao Han,Junze Xie,Nannan Dai,Liling Zhuo,Jianhong Gu,Jianchun Bian,Yan Yuan,Xuezhong Liu,Zongping Liu 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1
Gap junctions mediate direct communication between cells; however, toxicological cascade triggered by nonessential metals can abrogate cellular signaling mediated by gap junctions. Although cadmium (Cd) is known to induce apoptosis in organs and tissues, the mechanisms that underlie gap junction activity in Cd-induced apoptosis in BRL 3A rat liver cells has yet to be established. In the present study, we showed that Cd treatment decreased the cell index (a measure of cellular electrical impedance) in BRL 3A cells. Mechanistically, we found that Cd exposure decreased expression of connexin 43 (Cx43), increased expression of p-Cx43 and elevated intracellular free Ca2+ concentration, corresponding to a decrease in gap junctional intercellular communication. Gap junction blockage pretreatment with 18b-glycyrrhizic acid (GA) promoted Cd-induced apoptosis, involving changes in expression of Bax, Bcl-2, caspase-3 and the mitochondrial transmembrane electrical potential (Δym). Additionally, GA was found to enhance ERK and p38 activation during Cd-induced activation of mitogen-activated protein kinases, but had no significant effect on JNK activation. Our results indicated the apoptosis-related proteins and the ERK and p38 signaling pathways may participate in gap junction blockage promoting Cd-induced apoptosis in BRL 3A cells.