Abstract The butt welding tests of 5.5mm thick pure nickel N6 plate were carried out by plasma arc welding (PAW) and ERNi-1wire-filled PAW. And the differences in microstructure and properties between two kinds of joints were studied. The results show that the wire-filled pure nickel N6 joint has good appearance without defects such as pores, cracks, and undercuts. Pure nickel N6 weld is single-phase austenite structure, and no phase transformation occurs during heating or cooling. The weld zone of PAW joint is characterized by coarse columnar grain with average grain size of 125.8 μm, while the weld zone of wire-filled joint is equiaxed grain with average grain size of 54.8 μm. The tensile strength of the wire-filled PAW joint is 337MPa and the elongation after fracture is 44%, which is 11.6% and 85.5% higher than that of the PAW joint. The corrosion rate of wire-filled PAW joint is 2.6908g/m2h, which is lower than that of PAW joint of2.8820g/m2h, and the corrosion rates of both joint are higher than the base metal. The alloy elements in the welding wire can supplement the alloy elements burned in the welding process. As the filler metal, the melted wire forms the joint with the melted base metal, avoiding the defects such as undercut and depression. Al and Ti elements in ERNi-1 wire have deoxidation and nitrogen fixation effect during welding thermal cycle process, which improves the resistance of weld to carbon monoxide and nitrogen porosity. In the process of nitrogen fixation, TiN particles are formed in the crystal or grain boundary. TiN particles at the grain becomes heterogeneous nucleation particles in the grain, which makes a large number of nucleation and increases the nucleation rate. TiN particles at grain boundaries act as "nails" to hinder the migration of austenite grain boundaries. In the deoxidization process, the deoxidized products Al2O3 and TiO2 are formed. However, large-size inclusions are formed owing to the high content of Al and Ti in the molten pool, which affects the performance of the joint. Therefore, the structure and performance of filler wire-filled PAW joint are better than those of PAW joint.

A composição e atividade antimicrobiana dos óleos essenciais obtidos de madeira de ágar originária de Aquilaria sinensis (Lour.) Gilg induzido por agente biológico da madeira de ágar, Lasiodiplodia theobromae (F), foram caracterizadas e comparadas com madeira de ágar selvagem (W) e árvores saudáveis não inoculadas (H) como controles positivo e negativo, respectivamente. A composição química de F foi investigada usando cromatografia gasosa-espectrometria de massas (GC-MS). O óleo essencial de F mostrou uma composição similar de W, sendo rico em sesquiterpenos e constituintes aromáticos. No entanto, o óleo essencial de H era abundante em alcanos. Os óleos essenciais de F e W mostraram ser inibidores mais potentes de L. theobromae, Fusariumoxysporum, e Candida albicans do que o óleo essencial de H. Nossas descobertas demonstram pela primeira vez que o óleo essencial obtido da madeira de ágar originado de A. sinensis induzido por L. theobromae teve uma alta similaridade com o óleo essencial da madeira de ágar selvagem, tanto em composição química como em atividade antimicrobiana. Além disso, a estratégia de madeira de ágar induzida por fungos pode ser potencialmente aplicada em madeira de ágar e produção de óleo essencial em árvores do gênero Aquilaria.

The composition and antimicrobial activity of essential oils obtained from agarwood originating from Aquilaria sinensis (Lour.) Gilg induced by a biological agent of agarwood, Lasiodiplodia theobromae (F), were characterized and compared to those from wild agarwood (W) and uninoculated healthy trees (H) as positive and negative control, respectively. The chemical composition of F was investigated using gas chromatography-mass spectrometry (GC-MS). The essential oil of F showed a similar composition to that of W, being rich in sesquiterpenes and aromatic constituents. However, the essential oil of H was abundant in alkanes. Essential oils of F and W were more potent inhibitors of L. theobromae, Fusarium oxysporum, and Candida albicans than the essential oil of H. Our findings demonstrate for the first time that the essential oil obtained from the agarwood originating from A. sinensis induced by L. theobromae had a high similarity to that of the essential oil of wild agarwood, both in chemical composition and in antimicrobial activity. Furthermore, the strategy of agarwood induced by fungi could be potentially applied in agarwood and essential oil production in Aquilaria trees.

Abnormal genome hypermethylation participates in the tumorigenesis and development of prostate cancer. Prostate cancer cells highly express DNA methyltransferase 3 (DMNT3) family genes, essential for maintaining genome methylation. In the present study, multi-target siRNA, based on the homologous region of the DNMT3 family, was designed for the in vitro investigation of its effects on the proliferation, migration, and invasion of TSU-PR1 prostate cancer cells. The consequential cell-cycle derangement, through DNMT3A/B or only DNMT3B silencing, was partially efficient, without affecting apoptosis. DNMT3A silencing had absolutely no effect on changing TSU-PR1 cell biological behavior. Hence, DNMT3B alone apparently plays a key role in maintaining the unfavorable behavior of prostate-cancer cells, thereby implying its potential significance as a promising therapeutic target, with DNMT3A simply in the role of helper.