Improvement of the Mechanical Properties of 1022 Carbon Steel Coil by Using the Taguchi Method to Optimize Spheroidized Annealing Conditions.

Cold forging is often applied in the fastener industry. Wires in coil form are used as semi-finished products for the production of billets. This process usually requires preliminarily drawing wire coil in order to reduce the diameter of products. The wire usually has to be annealed to improve its cold formability. The quality of spheroidizing annealed wire affects the forming quality of screws. In the fastener industry, most companies use a subcritical process for spheroidized annealing. Various parameters affect the spheroidized annealing quality of steel wire, such as the spheroidized annealing temperature, prolonged heating time, furnace cooling time and flow rate of nitrogen (protective atmosphere). The effects of the spheroidized annealing parameters affect the quality characteristics of steel wire, such as the tensile strength and hardness. A series of experimental tests on AISI 1022 low carbon steel wire are carried out and the Taguchi method is used to obtain optimum spheroidized annealing conditions to improve the mechanical properties of steel wires for cold forming. The results show that the spheroidized annealing temperature and prolonged heating time have the greatest effect on the mechanical properties of steel wires. A comparison between the results obtained using the optimum spheroidizing conditions and the measures using the original settings shows the new spheroidizing parameter settings effectively improve the performance measures over their value at the original settings. The results presented in this paper could be used as a reference for wire manufacturers.

Genes are differentially expressed at transcriptional level of Neocaridina denticulata following short-term exposure to nonylphenol.

To assess the toxicity of nonylphenol towards aquatic crustaceans, Neocaridina denticulata were exposed short-term to sublethal concentration (0.001-0.5 mg/L). Following treatment, differentially expressed genes were identified using suppression subtractive hybridization on samples prepared from whole specimens. There were 20 differentially expressed sequence tags that corresponded to known genes and could be divided into six functional classes: defence, translation, metabolism, ribosomal gene expression, respiration, and genes involved in the stress response. Using semi-quantitative RT-PCR, we found that 14 of the differentially expressed sequence tags significantly responded to nonylphenol, including six at a nominal concentration of 0.01 mg/L; among them, 12 genes were down-regulated. These results suggest that under non-lethal concentrations of nonylphenol, the polluted aquatic environment may still present a potential risk to N. denticulata.

Differentially enhanced gene expression in hemocytes from Macrobrachium rosenbergii challenged in vivo with lipopolysaccharide.

In order to better understand the immune response in prawns after treatment with the immunostimulant lipopolysaccharide (LPS), in this study, the differential gene expression of the hemocytes from LPS-injected versus non-injected prawns (Macrobrachium rosenbergii) were isolated and identified using suppression subtractive hybridization (SSH). The hemocytes were extracted after treatment for 1, 6, and 12h. The upregulated genes (i.e., where gene expression was elevated) were identified and could be divided into four classes on the basis of physiological function: genes concerning defense-related molecules, genes involved in energy-production (respiration), genes related to protein synthesis and folding, and genes with unknown function. The time-course for gene expression indicated that, except for expression of the gene anti-microbial peptide (amp), which was increased at 12h after LPS treatment, the expression of the other two immune-related genes was much earlier (at 1h), including alpha-2-macroglobulin (alpha2-M) and Mas-like protein (mas). These results suggest that in the early phase of LPS stimulation some immune reactions regulated by alpha-2M and Mas may be induced, such as the activation of prophenoloxidase activating system, opsonization, and anti-microbial activity. In addition, six unigenes with unproven function were particularly interesting and worthy of further study because their expression in LPS-treated hemocytes was clearly enhanced.

Initiation of signal transduction of the respiratory burst of prawn haemocytes triggered by CpG oligodeoxynucleotides.

Phagocytosis is important in the immune system of the prawn and is believed to be a defence parameter. Previous studies have demonstrated that CpG oligonucleotides enhance the activation of the prophenoloxidase activating system of the prawn through either the G-protein/protein kinase C (PKC) or the cAMP pathway. This study investigated the influence of CpG ODN on the respiratory burst used as the indicator of phagocytic activity and on the initiation of the signal pathway in haemocytes of Macrobrachium rosenbergii. When haemocytes were treated in vitro with 50 microg ml(-1) of ODN2006 for 15 min, the increase of nitroblue-tetrazolium (NBT) reduction suggested that the respiratory burst of haemocytes can be enhanced by ODN2006 stimulation. In an attempt to determine which signal transduction pathway is involved in the enhancement effect, haemocytes were separately treated with activators or inhibitors of specific signalling components. The results showed that the NBT reduction of haemocytes increased after treatment with sodium fluoride (a G-protein activator) and decreased after treatment with GDP-beta-S (a G-protein inhibitor). When ODN2006-stimulated haemocytes were treated with GDP-beta-S, the inductive effect was significantly reduced. In haemocytes treated with 8-bromo-cAMP (a PKA activator), the NBT reduction was not significantly different from the control. The addition of phosphodiesterase-inhibiting caffeine, which inhibits the degradation of cAMP, decreased the NBT reduction of ODN2006-stimulated haemocytes; however, the addition of phenol-12-myristate-13-acetate (PMA) significantly increased the NBT reduction. When PMA-stimulated haemocytes were treated with chelerythrine (a PKC inhibitor), the induced NBT reduction was significantly reduced. Furthermore, the study of ODN2006-stimulated haemocytes treated with chelerythrine showed that the enhancement effect of ODN2006 on the NBT reduction was significantly decreased. All results suggest that the enhancement of the respiratory burst of prawn haemocytes is induced by ODN2006 via a PKC-activating signalling pathway, but negatively regulated via the cAMP pathway.