Estimating plot-level forest structural attributes using high spectral resolution ASTER satellite data in even-aged Eucalyptus plantations in southern KwaZulu-Natal,South Africa

This study assessed the suitability of both visible and shortwave infrared of ASTER reflectance bands and various vegetation indices for estimating forest structural attributes of Eucalyptus species. The study was conducted in even-aged monoculture plantations of E. grandis and E. nitens in the southern KwaZulu-Natal Midlands of South Africa. Empirical relationships between forest structural attributes, i.e. stems per hectare (SPHA), diameter at breast height (DBH), mean tree height (MTH), basal area and volume, and ASTER data were derived using correlation and canonical correlation analysis (CCA). The results indicated weak relationships between the studied forest structural attributes and ASTER data. In the younger plantation stands (4–6 years) the adjusted R ² values from CCA regression for SPHA, DBH, MTH, basal area and volume were 54.2, 63.5, 33.8, 25.4 and 30.3, respectively. The adjusted R ² values in the mature stands (7–9 years) were distinctly weaker with values of 50.7, 55.8, 25.1, 20.2 and 27.3 for SPHA, DBH, MTH, basal area and volume, respectively. The results imply that ASTER satellite data are not applicable to forest structural attribute estimation in commercially managed forest stands.     

The therapeutic effects of SET/I2PP2A inhibitors on canine melanoma

Canine melanoma is one of the most important diseases in small animal medicine. Protein phosphatase 2A (PP2A), a well conserved serine/threonine phosphatase, plays a critical role as a tumor suppressor. SET/I2PP2A is an endogenous inhibitor for PP2A, which directly binds to PP2A and suppresses its phosphatase activity. Elevated SET protein levels have been reported to exacerbate human tumor progression. The role of SET in canine melanoma, however, has not been understood. Here, we investigated the potential therapeutic role for SET inhibitors in canine melanoma. The expression of SET protein was observed in 6 canine melanoma cell lines. We used CMeC-1 cells (primary origin) and CMeC-2 cells (metastatic origin) to generate cell lines stably expressing SET-targeting shRNAs. Knockdown of SET expression in CMeC-2, but not in CMeC-1, leads to decreased cell proliferation, invasion and colony formation. Phosphorylation level of p70 S6 kinase was decreased by SET knockdown in CMeC-2, suggesting the involvement of mTOR (mammalian target of rapamycin)/p70 S6 kinase signaling. The SET inhibitors, OP449 and FTY720, more effectively killed CMeC-2 than CMeC-1. We observed PP2A activation in CMeC-2 treated with OP449 and FTY720. These results demonstrated the potential therapeutic application of SET inhibitors for canine melanoma.     

动物组蛋白H3K4三甲基化转移酶MLL3的生物信息学分析

[目的]对动物组蛋白H3K4三甲基化转移酶MLL3进行生物信息学分析。[方法]利用生物信息学的方法,对小鼠MLL3的基因结构、氨基酸序列、系统进化树、染色体定位和共线性等问题进行分析。[结果]编码合成的小鼠MLL3蛋白质一级结构包括7个锌指结构域、1个HMG-box(高迁移率族蛋白)、1个FYRN(N-末端富含苯丙氨酸或酪氨酸区域)、1个FYRC(C-末端富含苯丙氨酸或酪氨酸区域)、1个SET域和1个postSET域;从序列对比和同源性上发现,该研究中的19种动物都基本上具有这些结构,说明这些结构在进化上是相对保守的,其中SET域具有高度的保守性,是维持组蛋白甲基化酶活性所必须的;从系统发生上看,19种动物在进化树上的位置与其分类地位相一致;在共线性分析中,虽然小鼠和人的MLL3基因位于不同的染色体上,但其上游和下游具有相同的基因,说明小鼠和人的MLL3基因具有共线性。[结论]不仅揭示了MLL3的核苷酸序列及其氨基酸序列的一级结构,为以后研究其高级结构和蛋白质的功能奠定了基础;同时也为后期进行小鼠MLL3基因的引物设计、启动子分析、基因的克隆、定位和表达的调控模式研究奠定了基础。     

Effects of p38 MAPK on SETD4 expression and location in p38 +/+ and p38 -/- cells treated with sodium arsenite

AIM: To investigate the expression and location of SET domain-containing 4(SETD4) protein in p38 ^+/+ and p38 ^-/- cells treated with sodium arsenite(NaAsO₂). METHODS: The expression and location of SETD4 were detected in different cells with or without NaAsO₂ treatment by Western blotting and immunofluorescence technique. RESULTS: The expression of SETD4 was detectable in both murine- and human-derived cells. Its distribution was found to be located in the whole cell, mainly in the cytoplasm. Further investigation also suggested that the protein expression of SETD4 was reduced in both p38 ^+/+ and p38 ^-/- cells 6 h after NaAsO₂ treatment. Moreover, SETD4 protein was translocated from cytoplasm to nucleus in p38 ^+/+ cells treated with NaAsO₂, which was unobvious in p38 ^-/- cells. CONCLUSION: SETD4 protein is expressed in various cells derived from different species and tissues, and it is mainly located in cytoplasm. NaAsO₂ treatment influences the expression of SETD4, and induces the translocation of SETD4 protein to nucleus, which might be involved in the p38 MAPK signal pathway.     

动物组蛋白H3K4三甲基化转移酶MLL3的生物信息学分析(英文)

[目的]对动物组蛋白H3K4三甲基化转移酶MLL3进行生物信息学分析,从而探寻其相对保守的进化过程以揭示组蛋白H3K4三甲基化转移酶MLL3在在人类癌症的中的作用。[方法]利用生物信息学的方法,对小鼠MLL3的基因结构、氨基酸序列、系统进化树、染色体定位和共线性等问题进行分析。[结果]编码合成的小鼠MLL3蛋白质一级结构包括7个锌指结构域、1个HMG-box(高迁移率族蛋白)、1个FYRN(N-末端富含苯丙氨酸或酪氨酸区域)、1个FYRC(C-末端富含苯丙氨酸或酪氨酸区域)、1个SET域和1个postSET域;从序列对比和同源性上发现,该研究中的19种动物都基本上具有这些结构,说明这些结构在进化上是相对保守的,其中SET域具有高度的保守性,是维持组蛋白甲基化酶活性所必须的;从系统发生上看,19种动物在进化树上的位置与其分类地位相一致;在共线性分析中,虽然小鼠和人的MLL3基因位于不同的染色体上,但其上游和下游具有相同的基因,说明小鼠和人的MLL3基因具有共线性。[结论]不仅揭示了MLL3的核苷酸序列及其氨基酸序列的一级结构,为以后研究其高级结构和蛋白质的功能奠定了基础;同时也为后期进行小鼠MLL3基因的引物设计、启动子分析、基因的克隆、定位和表达的调控模式研究奠定了基础。     

Effect of SET7/9-mediated endoplasmic reticulum stress on arsenic-induced hepatocyte apoptosis

AIM:To investigate the effect of SET7/9 (SET domain containing 7/9)-mediated endoplasmic reticulum stress (ERS) on protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway, and to explore the mechanisms of arsenic-induced hepatocyte apoptosis. METHODS:Human liver LO2 cells were divided into control group, arsenic poisoning model group, negative transfection group and SET7/9 siRNA transfection group. The apoptosis of the LO2 cells in each group was analyzed by flow cytometry. The protein levels of SET7/9, glucose-regulated protein 78 (GRP78), PERK and p-PERK in the LO2 cells of each group were observed by Western blot. RESULTS:Inhibition of SET7/9 expression reduced the apoptotic rate of arsenic-induced LO2 cells. Arsenic exposure increased the expression of SET7/9 in the LO2 cells. Arsenic exposure increased the protein levels of GRP78 and p-PERK in the LO2 cells, but decreased the protein levels of GRP78 and p-PERK after transfection with SET7/9 siRNA (P<0.05). CONCLUSION:Arsenic exposure induces hepatocyte apoptosis by increasing SET7/9 to activate ERS by PERK signaling pathway.     

氮-(ω-三丁基锡)烷基邻苯二甲酰亚胺的光诱导单电子转移环化反应

氮-(ω-三丁基锡)烷基邻苯二甲酰亚胺在光诱导下生成环化物,溶剂亲核性影响其光反应机制:在强亲核性溶剂中反应按单电子转移(SET)机制进行,并以很高的产率得到环化物;在弱亲核性溶剂中氢转移和单电子转移(SET)机制反应同时存在。     

各种加密通信协议的比较分析

随着电子商务的普及越来越多的人进行再线交易，各种电子商务的安全交易协议也应用的更加广泛，PKI、SSL、SET这些安全协议就是其中的典型代表。这里在探讨PKI、SSL、SET技术原理的基础上．对它们各自的作用、技术实现、工作流程等进行了描述；对它们之间的联系、区别、应用范围进行进行了深入的分析。     

利用免疫共沉淀技术验证SET与eEF1A1在人肝细胞内的相互作用(摘要)(英文)

[目的]探讨SET与eEF1A1在人肝细胞内是否存在相互作用。[方法]以人L-02肝细胞为材料,在非变性条件下提取总蛋白,将鼠抗人SET、兔抗人eEF1A1抗体分别加到总蛋白提取物中,用偶联了琼脂糖珠的ProteinA/G分离抗原抗体复合物,最后分别用兔抗人eEF1A1、鼠抗人SET抗体进行Western blotting检测。[结果]在用SET抗体免疫共沉淀下来的蛋白复合物中检测到eEF1A1,同时在用eEF1A1抗体免疫共沉淀下来的蛋白复合物中也检测到SET。[结论]SET与eEF1A1在人肝细胞内存在相互作用。