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A stainless steel material is used as components for storing hydrogen gas and liquid hydrogen, or for transportation raw material and oil in storage container. Brittle fracture associated with hydrogen is observed for stainless steel and these phenomena of hydrogen embrittlement were very important for wide-ranging application of stainless steel. Many researchers have studied the hydrogen embrittlement from the mechanical and metallographic point of views. The aim of this study is to identify the material degradation by hydrogen embrittlement for 316L stainless steel using nondestructive evaluation. That is, the relationship between the mechanical properties of 316L stainless steel by hydrogen charging and nondestructive technique of acoustic emission technique and an ultrasonic wave is to be clarified. The relationship between fractography and ultrasonic wave characteristics on hydrogen charged material for 0hr and 24hr was discussed. SEM and optical microscope were used to inspect the fracture surface of hydrogen charged material. The fracture surface of the charged specimen became brittle, especially on the surface nearby. AE parameters of event, count, energy, amplitude and frequency were analyzed according to the degree of the damage of hydrogen charged stainless steel.

This paper dealt with the interfacial bonding properties of Cu/Al clad materials by the variation of aging treatment times. Cu/Al clad materials were fabricated by a hot-pressing process. A subsequent heat treatment was also performed for the interfacial strengthening of Cu/Al clad materials. The characterization of Cu/Al clad materials was evaluated by means of OM, SEM, EDX and Knoop hardness test. Several diffusional layers were created at the interfacial region of Cu/Al clad materials, due to the chemical reaction of Cu and Al elements. The thicknesses of interfacial diffusion layers for Cu/Al clad materials increased with the increase of aging treatment time, accompanying the variation of intermetallic compounds. The hardness strengthening of diffusion layers by the increase of aging treatment time was also affected by the formation of η2 phase at the bonding interfacial region.

The unique metabolic profile of cancer (aerobic glycolysis) is an attractive therapeutic target for cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase, has been shown to reverse glycolytic phenotype and induce mitochondrion-dependent apoptosis. In the present study, we investigated the effects of S6 kinase 1 (S6K1) inhibition on DCA-induced cell death and the underlying mechanisms in breast cancer cells. Cell death was evaluated by annexin V and PI staining. The synergistic effects of DCA and PF4708671 were assessed by isobologram analysis. Small interfering RNA (siRNA) was used for suppressing gene expression. The mRNA and protein levels were measured by RT-PCR and Western blot analysis, respectively. PF4708671, a selective inhibitor of S6K1, and knockdown of S6K1 with specific siRNA enhanced DCA-induced cell death. Interestingly, a combination of DCA/PF4708671 markedly reduced protein expression of a glycolytic enzyme, hexokinase 2 (HK2). Suppression of HK2 activity using specific siRNA and 2-deoxyglucose (2-DG) further enhanced cell sensitivity to DCA/PF4708671. Overexpression of Myc-tagged HK2 rescued cell death induced by DCA/PF4708671. Based on these findings, we propose that inhibition of S6K1, in combination with the glycolytic inhibitor, DCA, provides effective cancer therapy.

Piperlongumine (PL) has been shown to selectively induce apoptotic cell death in cancer cells via reactive oxygen species (ROS) accumulation. In this study, we characterized a molecular mechanism for PL-induced cell death.Cell viability and cell death were assessed by MTT assay and Annexin V-FITC/PI staining, respectively. ROS generation was measured using the H2DCFDA. Small interfering RNA (siRNA) was used for suppressing gene expression. The mRNA and protein expression were analyzed by RT-PCR and Western blot analysis, respectively.We found that PL promotes C/EBP homologous protein (CHOP) induction, which leads to the up-regulation of its targets Bim and DR5. Pretreatment with the ROS scavenger N-acetyl-cysteine abolishes the PL-induced up-regulation of CHOP and its target genes, suggesting an essential role for ROS in PL-induced CHOP activation. The down-regulation of CHOP or Bim with siRNA efficiently attenuates PL-induced cell death, suggesting a critical role for CHOP in this cell death. Furthermore, PL potentiates TRAIL-induced cytotoxicity in breast cancer cells by upregulating DR5, as DR5 knockdown abolished the sensitizing effect of PL on TRAIL responses.Overall, our data suggest a new mechanism for the PL-induced cell death in which ROS mediates CHOP activation, and combination treatment with PL and TRAIL could be a potential strategy for breast cancer therapy.

During the use of API X70 steel as a pipeline structural material for the transportation of natural gas, hydrogen embrittlement can occur due to the hydrogen contained in natural gas. The aim of this study is to investigate the effects of the hydrogen content under high-pressure hydrogen gas conditions on the hydrogen embrittlement of air-cooled API X70 steel. The air-cooled API X70 steel was manufactured by hot rolling and was then air-cooled to room temperature. Tensile test specimens were held for 0 h, 1000 h, and 2000 h within a pressure vessel filled with 100% hydrogen gas at a gas pressure of 10 MPa, with the tensile tests then performed at room temperature. The microstructure of the API X70 steel consists of coarse polygonal ferrite, coarse pearlite, and fine acicular ferrite. The yield and tensile strength increased and elongation decreased considerably after a holding time of 2000 h compared to those of 0 h and 1000 h within the pressure vessel. The morphology of the fracture surface changed from ductile to brittle upon hydrogen gas charging. Secondary cracks were observed in both of the hydrogen-gas-charged specimens. No external cracks were formed on the surface of the tensile-tested specimen with a 0 h holding time; however, many external cracks were observed on the specimen surface subjected to hydrogen gas charging.

The objective of this research is to study the effect of various hydrogen charging quantities in austenitic stainless steel using nondestructive technique. The hydrogen charging equipment was designed to make charging the steel, and the specimens were charged for 2, 4, 10 and 24 hours in the equipment. An acoustic emission (AE) technique, nondestructive test, was used to evaluate the dynamic behavior of the hydrogen charged austenitic stainless steel specimen. The tensile load was applied the charged specimen with the attached AE sensor, and elastic waves caused plastic deformation and cracking in the specimen by external tensile loading were caught at the AE sensor and analyzed by the AE parameters such as count, energy, duration time, event and amplitude. In addition, ultrasonic wave was also used to evaluate the degree of hydrogen charging. The velocity and the attenuation ratio of the ultrasonic wave on the specimen with different hydrogen charging conditions were measured. The velocity was not changed but the attenuation ratio was linearly increased with the hydrogen charging time. The relationship between the results of nondestructive test including AE test and ultrasonic test and fractographic analysis by using SEM was discussed.

A TIG welded 316 stainless steel materials will have a large impact on the design and the maintenance of invessel components including pipes used in a nuclear power plant, and it is important to clear the dynamic behavior in the weld part of stainless steel. Therefore, nondestructive techniques of acoustic emission (AE) and ultrasonic wave were applied to investigate the damage behavior of welded stainless steel. The velocity and attenuation ratio of the ultrasonic wave at each zone were measured, and a 10 MHz sensor was used. We investigated the relationship between dynamic behavior and AE parameters analysis and derived the optimum parameters to evaluate the damage degree of the specimen. By measuring the velocity and the attenuation of an ultrasonic wave propagating each zone of the welded stainless steel, the relation of the ultrasonic wave and metal structure at the base metal, heat affected zone (HAZ) metal and weld metal is also discussed. The generating tendency of cumulated counts is similar to that of the load curve. The attenuation ratios from the ultrasonic test results were 0.2 dB/mm at the base zone, and 0.52 dB/mm and 0.61 dB/mm at the HAZ zone and weld zone, respectively.

Berberine has been reported to inhibit tumor growth in lung cancer. Thus, the effects of berberine on cancer cells as well as the cancer stem cell (side population; SP) fraction were investigated in the H460 lung cancer cell line, and the effects of berberine treatment on cell growth, cell cycle, and cell death were evaluated. Changes in the SP fraction were examined after treatment with berberine, 5-fluorouracil (5-FU), and co-treatment. Berberine inhibited cancer cell growth in a dose-dependent manner. Treatment of the cells with berberine resulted in a 4% increase in cell death and an 8% increase in the number of cells of G0/G1 phase, compared to the untreated control. To examine the relationship between berberine and cancer stem cells, the SP fraction was analyzed. Surprisingly, the SP cell fraction was increased upon berberine treatment and further increased after cotreatment with 5-FU. These results are in contrast to the study of Kim et al. (2008) with MCF-7 breast cancer cells, in which berberine inhibited the growth of both cancer cells and the corresponding cancer stem cells. Results of the present study suggest that berberine should be used with caution in the treatment of various cancers, despite its positive effect on cancer cell growth inhibition.

A mode-switching servo is widely used in solid immersion lens (SIL)-based near-field recording (NFR) systems to control the air gap between the bottom surface of the SIL and the top surface of the rotating media. In the mode-switching servo, it is very important to reduce the initial overshoot in the near field region, as this overshoot can cause collisions between the SIL and the media, and increase the settling time required for the SIL to be initially moved to the final air gap. In this paper, the mode-switching servo with a brake pulse is proposed to reduce the initial overshoot and settling time. The effectiveness of the proposed method is proved by experiments of which results show that the minimum air gap due to the initial overshoot is improved from 6.86 to 18.73 nm and the settling time is reduced from 30 to 4.5 ms.

Spinal metastatic disease is characterised by the preservation of the intervertebral disc structure, even after severe destruction of the vertebral body by neoplastic tissues. Anatomical features of the discs are thought to be the reason for the disc’s resistance to metastatic cancer. However, little is known about the biochemical mechanism to prevent or attenuate the local invasion of cancer cells into the discs. The purpose of this study was to investigate the hypothesis that Fas ligand (FasL) produced by nucleus pulposus cells can kill Fas-expressing cancer cells infiltrating into the discs by the activation of caspases. Fas-expressing MCF-7 breast cancer cells were cultured with (experimental group) and without (control group) supernatant of nucleus pulposus cells containing FasL (50 pg/ml) for 48 h. The apoptosis of MCF-7 breast cancer cells was determined by the TUNEL technique. In addition, the activation of caspase-8, -9 and -3 was investigated by Western blot analysis. After treatment with supernatant of the nucleus pulposus cells containing FasL, the apoptosis of MCF-7 breast cancer cells was significantly increased, along with the activation of caspase-8, -9 and -3 compared with those of the control group. Our results suggest that the Fas/FasL interaction of nucleus pulposus and cancer cells might be a potential mechanism of the disc’s resistance to metastatic cancer.

Poly(ethylene oxide)-LiClO4-TiO2 organic-inorganic hybrids were synthesized for Li-polymer battery electrolytes using sol-gel processing. The hybrids containing TiO2 component showed the uniform film formation and also increased ionic conductivity. The hybrid films containing 10 wt% TiO2 showed the smooth surface morphologies and also the highest ionic conductivity. The molecular-level hybrid formation between PEO and TiO2 components was identified using FTIR analyses. The hybrids containing TiO2-Al2O3 mixtures showed the enhanced ionic conductivity compared to those containing only TiO2 most probably due to the Lewis acidic group formation at the surface of Al2O3 components. The PEO-LiClO4-TiO2-Al2O3 hybrids showed high stability both in ionic conductivity and crystallinity. By the sol-gel processing two inorganic components were successfully introduced in the PEO matrix and high-performance solid electrolytes were achieved.

Yuzu (Cittus junos) trees were examined from six geographically separate provinces in the Republic of Korea, including four islands (Geoje, Namhae, Wan, and Jeju), 1 peninsula (Goheung), and 1 inland area (Boseong). The population of sequence variants of citrus tristeza virus (CTV) was isolated and analyzed by single-strand conformation polymorphism (SSCP) analysis of cDNA from thep20 gene. SSCP profiles of 65 PCR products showed different band patterns but with similar intensities. Sixteen haplotypes were subgrouped according to their SSCP profiles and severity of symptoms. Their genomes were sequenced and compared. DNA analysis of thep20 genes revealed nucleotide identities ranging from 88-99.8%. Based on SSCP analysis, the pathologically mild isolates of CTV yielded two to three DNA bands, whereas the most virulent isolates contained more than two bands. Comparisons of these physically separate haplotypes suggest that CTV isolates with multiple SSCP profiles could have arisen as a result of a mixed infection and genetic recombination of two divergent isolates. Plants with severe disease symptoms, such as stem pitting, closely corresponded to a CTV strain showing typical SSCP profiles in Florida (USA) and Japan.

TiNi/A16061 shape memory alloy (SMA) composite was fabricated by hot press method to investigate the microstructure and mechanical properties. Interface bonding between TiNi reinforcement and A1 matrix was observed by using SEM and EDS. Pre-strain was imposed to generate compressive residual stress inside composite. A tensile test for specimen, which underwent pre-strain, was performed at high temperature to evaluate the variation of strength and the effect of pre-strain. It was shown that interfacial reactions occurred at the bonding between matrix and fiber, creating two inter-metallic layers. And yield stress increased with the amount of pre-strain. Acoustic Emission technique was also used to nondestructively clarify the microscopic damage behavior at high temperature and the effect of pre-strain of TiNi/A16061 SMA composite.

Aminoalcoholphosphotransferase catalyzes the synthesis of phosphatidyicholine and phosphatidylethanolamine from diacylglycerol plus CDP-choline or CDP-ethanolamine as the phosphobase donor. We screened a cDNA library to isolate a clone for use in studying the structure and expression pattern of this enzyme fromPimpinella brachycarpa. TheP. brachycarpa aminoalcoholphosphotransferase cDNA contains an open reading frame of 1,170 bp coding for a protein of 389 amino acids. The deduced amino acid sequence shares over 90% similarity with other aminoalcoholphosphotransferase sequences. Hydropathy profile analysis suggests that the secondary structure ofP. brachycarpa aminoalcoholphosphotransferase is very similar to that of soybean and Chinese cabbage enzymes, having an overall hydrophobicity and the same number of predicted transmembrane helices. The catalytic domain contains the CDP-alcohol phosphotransferase motif with two aspartate residues. Reverse transcriptase-PCR analysis indicates that the expression ofP. brachycarpa AAPT is regulated by temperature.