Effects of Genetic and Pharmacologic Inhibition of COX-2 on Colitis-associated Carcinogenesis in Mice

COX-2 has been inappropriately overexpressed in various human malignancies, and is considered as one of the representative targets for the chemoprevention of inflammation-associated cancer. In order to assess the role of COX-2 in colitis-induced carcinogenesis, the selective COX-2 inhibitor celecoxib and COX-2 null mice were exploited in an azoxymethane (AOM)-initiated and dextran sulfate sodium (DSS)-promoted murine colon carcinogenesis model. The administration of 2% DSS in drinking water for 1 week after a single intraperitoneal injection of AOM produced colorectal adenomas in 83% of mice, whereas only 27% of mice given AOM alone developed tumors. Oral administration of celecoxib significantly lowered the incidence as well as the multiplicity of colon tumors. The expression of COX-2 and inducible nitric oxide synthase (iNOS) was upregulated in the colon tissues of mice treated with AOM and DSS, and this was inhibited by celecoxib administration. Likewise, celecoxib treatment abrogated the DNA binding of NF-kappa B, a key transcription factor responsible for regulating expression of aforementioned pro-inflammatory enzymes, which was associated with suppression of I kappa B alpha degradation. In the COX-2 null (COX-2(-/-)) mice, there was about 30% reduction in the incidence of colon tumors, and the tumor multiplicity was also markedly reduced (7.7 +/- 2.5 vs. 2.43 +/- 1.4, P < 0.01). As both pharmacologic inhibition and genetic ablation of COX- 2 gene could not completely suppress colon tumor formation following treatment with AOM and DSS, it is speculated that other pro-inflammatory mediators, including COX-1 and iNOS, should be additionally targeted to prevent inflammation-associated colon carcinogenesis.

Superconformal Cu Electrodeposition on Various Substrates

For application to Cu interconnection, superconformal electrodeposition has been performed on various substrates, including physical vapor deposited ~PVD! Cu, two kinds of electroless deposited ~ELD! Cu, TiN barrier, and metallorganic chemical vapor deposited Ru. ELD Cu with HCHO as the reducing agent was compatible with PVD Cu in terms of conformal characteristics and film continuity. Both PVD and ELD Cu seed layers enabled superconformal filling with distinct bumps. Superfilling was also attained on resistive substrates of TiN and Ru through Pd activation and subsequent slight seeding by electrodeposition to enhance the action of additives

Leveling of Superfilled Damascene Cu Film Using Two-Step Electrodeposition

To enhance the compatibility of electrodeposition with the chemical mechanical polishing process, we attempted to prevent step formation on active areas. In the absence of benzotriazole BTA , the step heights increased with the decrease in the pattern width and the increase in the pattern density due to the locally condensed accelerator. However, the addition of BTA significantly suppressed the deposition kinetic through the deactivation of the accelerator. The two-step electrodeposition with modulated accelerator and BTA concentrations was found to be effective in the retardation of bump formation and the prevention of bumps from growing without an impact on the superfilling

Acceleration Effect of CuCN in Ag Electroplating for Ultralarge-Scale Interconnects

The addition of CuCN accelerated the deposition rate in cyanide-based Ag electroplating. The catalytic effect came from the high-order complexation of Cu with the free CN− ions in electrolyte. It changed the equilibrium state of the electrolyte, presented as an increase in the amount of Ag CN 2 − compared to Ag CN 3 2−. Because Ag CN 2 − could be reduced more easily, Ag electroplating was accelerated. Fourier transform infrared analysis showed the equilibrium change with the increase in Ag CN 2 − peak according to the CuCN addition. For superfilling, it is necessary to localize the complexation on the Cu surface.This work was supported by the Korea Science and Engineering Foundation through the Research Center for Energy Conversion and Storage RCECS , Dongbu HiTeK, and also by the Institute of Chemical Processes ICP

Copper Bottom-Up Filling by Electroplating Without any Additives on Patterned Wafer

In conventional Cu electroplating, various additives are used to fill pattern without defects in patterned wafers. Pulse plating and electrochemical oxidation were used to deposit Cu without any additives. Defects such as voids and seams were generated if only pulse plating was carried out. Electrochemical oxidation was performed to remove Cu metal containing defects and to remain Cu species only at the bottom part of the trenches. Then, defect free Cu films could be obtained when Cu electroplating without additives was performed on the etched substrate.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage RCECS , also by the Institute of Chemical Processes ICP in Seoul National University

Pathogen-inducible CaUGT1 is involved in resistance response against TMV infection by controlling salicylic acid accumulation

AbstractCapsicum annuum L. Bugang exhibits a hypersensitive response against Tobacco mosaic virus (TMV) P0 infection. The C. annuum UDP-glucosyltransferase 1 (CaUGT1) gene was upregulated during resistance response to TMV and by salicylic acid, ethephon, methyl viologen, and sodium nitroprusside treatment. When the gene was downregulated by virus-induced gene silencing, a delayed HR was observed. In addition, free and total SA concentrations in the CaUGT1-downregulated hot pepper were decreased by 52% and 48% compared to that of the control plants, respectively. This suggested that the CaUGT1 gene was involved in resistance response against TMV infection by controlling the accumulation of SA