退火温度对用PⅢ方法制备共掺杂p型ZnO薄膜结构和性能的影响

采用射频磁控共溅射的方法制备出ZnO:Al薄膜,以NO和O2为源气体(V(O2)/V(O2+NO)=75%),采用等离子体浸没离子注入(PⅢ)方法对薄膜进行注入得到ZnO:Al:N薄膜,注入剂量为2.23×1015 cm-2,并在N2氛围下对样品进行了不同温度的退火处理.通过XRD图谱、霍尔效应(Hall)测试结果、紫外-可见光透射光谱等对样品的结构和性能进行了分析,着重研究了退火温度对ZnO:Al:N薄膜性质的影响.结果表明,退火可以使注人产生的ZnO(N2)3团簇分解,并且使N以替位O的方式存在.当退火温度达到850℃时,ZnO薄膜实现了p型反转,实现p型反转的ZnO:AliN薄膜载流子浓度可达3.68×1012cm-3,电阻率为11.2 Ω·cm,霍耳迁移率为31.4 cm2·V-1·s-1.     

PGE patterns of ores of Dajing Cu-polymetallic deposit in Linxi County,Inner Mongolia: Indicator to source of metallogenic elements

By comparing PGE patterns of sulfide ores with that of basic-ultrabasic dikes occurring in the Dajing Cu-polymetallic deposit, we discover that there are similar positive slopes between the basic-ultrabasic dikes and the black ores composed mainly of sphalerite and galena, reflecting affinity of their source. The PGE patterns of the yellow ores composed basically of chalcopyrite, arsenopyrite and pyrite are actually different. One is close to the pattern of the mantle lherzolite, and others resemble the pattern of the basic rocks. However, the concentrations of Ru are higher in the yellow ores, reflecting that sulfur attains or approaches saturation in their parent magma. The PGE characteristics of ores and dikes show that the magmas derived from the deep of crust and the metallogenic elements were supplied mainly by growth material of the crust. In addition, the mantle-derived magma also offered some elements.     

Genistein inhibits human TNF-α-induced porcine endothelial cell adhesiveness for human monocytes and natural killer cells

Cellular immune response is a major barrier to xenotransplantation. Human tumor necrosis factor-α (hTNF-α) possesses cross-species activity and directly amplifies the immune rejection via the upregulation of adhesion molecules on porcine endothelium. We investigated the role of protein tyrosine phosphorylation in the induction of expression of E-sclectin and vascular cell adhesion molecule-1 (VCAM-1), and the augmentation of adhesion of human peripheral blood monocytes (PBMo) and natural killer cells (PBNK), after rhTNF-α-stimulation of porcine aortic endothelial cells (PAEC) in vitro, rhTNF-α-increased adhesiveness of PAEC for both PBMo and PBNK was dose-dependently reduced by pretreatment of PAEC with the selective protein tyrosine kinase (PTK) inhibitor genistein. The inhibitory effect occurred at the early time of PAEC activation triggered by rhTNF-α, and was completely reversible. PTK activity assay indicated that genistein also suppressed rhTNF-α stimulated activation of protein tyrosine kinases (PTKs) in PAEC in a dose-dependent manner. Flow cytometric analysis showed that genistein inhibited the upregulation of E-selectin and VCAM-1 by rhTNF-α. These results suggest that PTKs may regulate the expression of E-selectin and VCAM-1 on PAEC and the adherence of PBMo and PBNK induced by rhTNF-α. Moreover, dietary genistein, used as an adhesion antagonist, may contribute to managing the cell-mediated rejection in the clinical application.     

Static three-dimensional culture of human hepatocarcinoma cell with microcarriers

Traditional monolayer culture is still the common method used in hepatocarcinoma cell culturein vitro. For lack of the structure similar to thatin vivo, it is disadvantageous in the research of the relation between structure and function. We established a three-dimensional (3-D) culture model of human hepatocarcinoma cell (BEL-7402)in vitro by using microcarrier cytodex-3 in static condition. The results of SEM, TEM, enzyme activity and flow cytometry indicated that the cells were polygonal-shaped and arranged in multilayers. Intercellular space was 0.5–2.0 μm wide where lots of microvilli could be seen. Adjacent cells were connected with desmosomes and localized membrane projects. More than 90% of the cells were viable and maintained the consumption of glucose and the expression of EGF receptor. The intracellular ALT, AST and LDH-L activities were higher in 3-D culture than those of monolayer culture. Compared with monolayer culture, this 3-D culture with the structure similar to trabecular hepatocarcinomain vivo is much more suitable for the research of the interactions of cell-cell and cell-microenvironment, and might be useful in the investigation of the mechanisms of invasion, metastasis, and multicellular drug resistance of tumor cells.     

Human endothelial senescence induced by IL-1α in vitro

Interleukin 1(IL-1) is an important proinflammatory cytokine that causes pleiotropic effects. Vascular endothelial cells stimulated by IL-1α can lead to the inflammatory response. Reactive oxygen species (ROS) are also generated at the site of inflammation and serve as an important factor against foreign invader. Here we report that long-term stimulation of human vein endothelial cells with IL-1α can accelerate their senescence associated with β-galactosidase activity. The flow cytometric analyses showed that most of the induced cells entered G0-G1 phase. DNA damage was more severe in senescent cells by comet assay. The induced cells by IL-1α had higher levels of ROS and malonyldialdehyde (MDA), lower activity of antioxidant enzymes and lower capacity of total antioxidant systems than control, which led to cell damage and cell degeneration, that is to say, which contributed to cellular senescence. Our results gave a direct proof to a new hypothesis-"the inflammation hypothesis of aging" on cellular level, and also provided a basis for the study on anti-aging and aging-related diseases.     

广西旱地耕作体系缓释氮肥效应试验研究

1998－2000年分别在广西的崇左县、南宁市郊区、来宾县等地进行甘蔗、龙眼、玉米施用不同缓释（或长效）氮肥的田间试验研究。试验采用常规肥料试验方法，甘蔗、玉米均设5个处理：对照（不施氮肥）、普通尿素、涂层尿素、长效碳铵、缓释尿素；龙眼除不设不施氮肥处理外，其余处理与甘蔗、玉米相同；各试验均设4次重复。结果表明，涂层尿素、缓释尿素分别比普通尿素增加原料蔗11．7％和5．3％，每公顷增糖1262kg和497kg，增糖率13．6％和5．3％；甘蔗当季对涂层尿素与缓释尿素中氮素的利用率分别此普通尿素高7．50％和2．85％（绝对值）。施用涂层尿素、缓释尿素和缓释碳铵的龙眼幼年树生长量与普通尿素处理无显著差异（F＞0．01）；施用涂层尿素的龙眼果实产量比普通尿素增产2．5％－13．6％。玉米施用缓释氮肥比施用普通尿素增产337．5－525．0kg/hm^2，增产率5．36％－7．74％；玉米施用缓释尿素、涂层尿素的氮素利用率比普通尿素分别提高5．14％、4．39％（绝对值）。缓释氮肥对甘蔗、龙眼、玉米有良好的供肥性，适用于氮素淋溶强烈的广西土壤。     

Phenotypic analysis of the medullary-type CD4-CD8+ thymocytes in mice

Phenotypic analysis of the medullary-type CD4-CD8+ (CD8SP) thymocytes has revealed phenotypic heterogeneity within this cell population. The phenotype of mature peripheral CD8+T cells is TCRαβ+CD3+Qa-2+HSA-3G11-6C10-, whereas in the medullary-type CD8SP thymocytes, 20% are Qa-2+; 33%, HAS-; 30%, 3G11-; and 70% are 6C10-. The disparate expression patterns of these four cell surface markers suggest that medullary-type CD8SP thymocytes may undergo phenotypic maturation process. According to the distribution of these four cell surface markers, six subgroups of CD8SP thymocytes have been identified. The precursor-progeny relationship along with developmental pathway is postulated as follows: 6C10+HSA+3G11-Qa-2-(r) 6C10+HSA+ 3G11+Qa-2-(r) 6C10-HSA+3G11+Qa-2-(r) 6C10-HSA-3G11+Qa-2-(r) 6C10-HSA-3G11Qa-2-(r) 6C10-HAS-3G11-Qa-2+, the cells in the last subgroup exit the thymus and home into periphery.     

Human endothelial senescence can be induced by TNF-α

TNF-α is one of the most important proinfiammatory cytokines in mediating multiple physio-pathological functions during immunological responses. Vascular endothelial cells, when stimulated by TNF-α2 can increase the expression of multiple cytokines and cellular adhesion molecules and, in turn, actively promote the inflammatory responses by recruiting and activating of leukocytes to the inflammatory site. In addition to endothelial death induced by TNF-α2 we found for the first time that TNF-α can also induce the human endothelial cells senescence. The induced senescent endothelial cells will display SA-β-Gal staining and they were arrested in G0-G1 phase. We found that Aψm would always be up-regulated in response to TNF-α stimulation at early time but when the cells become senescent, A ψmshows a tendency to decrease. It may reflect the sthenic function of mitochondria at early time in response to TNF-αstimulation and decay when the endothelial cells were induced senescent. ROS fluctuates at early time and also decreases when the endothelial cells become senescent. Our results show that the change of mitochondrial function may be related to the senescent process.``     

广西甘蔗种植区土壤钾素肥力分级研究

统计分析1991年至2001年在广西来宾、合浦、贵港、博白等县的红壤、赤红壤和砖红壤上进行的82个施钾肥增产效应田间试验资料,分砂土、壤土、粘土质地对广西甘蔗种植区土壤钾素肥力进行分级.结果表明,甘蔗种植区土壤速效钾肥的临界值为砂土46.2 mg/kg,壤土51.4 mg/kg,粘土60 mg/kg.砂土、壤土和粘土土壤速效钾肥分级指标分别为低＜46 mg/kg、＜52 mg/kg和＜60 mg/kg,中46～90 mg/kg、52～110 mg/kg和60～120 mg/kg,高＞90 mg/kg、＞110 mg/kg和＞1 20 mg/kg.