A Novel Hydroforming Process by Combining Internal and External Pressures for High-Strength Steel Wheel Rims.

As one of the key safety components in motor vehicles, the steel wheel rim is commonly fabricated with the roll forming process. However, due to the varied cross-sections of the rim and the low formability of high-strength steel, it is difficult to produce thin-wall and defect-free wheel rims to realize the purpose of light weight. To solve these problems, a novel hydroforming process by combining internal and external pressures (HIEP) was proposed to produce thin-wall wheel rims in the current study. The designed initial tube with diameter between the maximum and minimum diameter of the wheel rim ensures dispersed deformation and effectively avoids local excessive thinning. During HIEP, a hydroforming process was performed with two successive stages: the external pressure and internal pressure stages. Theoretical analysis and finite element method (FEM) were jointly used to investigate the effect of process parameters on the wrinkling and thinning. With the optimized parameters for internal and external pressure, the wrinkling of wheel rims is prevented under compressive state during the external pressure forming stage. Additionally, HIEP was experimentally carried out with high-strength steel rims of 650 MPa ultimate tensile strength (UTS). Finally, wheel rims with weight reduction of 13% were produced successfully, which shows a uniform thickness distribution with a local maximum thinning ratio of 11.4%.

[High Expression of Multidrug Resistance Gene-1 Can Aggravate Resistance to Methotrexate in Rheumatoid Arthritis Patients].

Objective To explore the role of multidrug resistance gene-1(MDR1)gene in methotrexate(MTX)resistance in patients with rheumatoid arthritis(RA).Methods Fibroblast-like synoviocytes(FLS)from RA patients were infected with recombinant adenovirus Ad-EGFP-MDR1 in vitro to obtain MDR1 over-expressed RA FLS.The transcription level of MDR1 gene and the expression level of its coding product P-glycoprotein(P-gp) rotein were detected by real-time PCR and Western blot analysis.The efflux function was verified by rhodamine 123 efflux assay.The resistance to MTX was detected by MTT assay.Results RA FLS were infected with recombinant adenovirus Ad-EGFP-MDR1;72 hours later,the particles size in MDR1 over-expressed RA FLS increased,the cell volume became larger,and the growth rate decreased.The transcription level of MDR1(1.4325±0.3924 vs.0.0650±0.0070;t=6.035,P=0.004),the expression level of P-gp protein(1.8667±0.2857 vs. 0.9367±0.0551;t=5.536,P=0.005),and the ability of extracellular rhodamine 123(979.43±196.81 vs.1680.06±147.04;t=-4.940,P=0.008) in MDR1 over-expressed RA FLS were significantly higher than those of negative virus control RA-FLS,and the survival rate of MDR1 over-expressed RA FLS was significantly increased at each concentration of MTX(P<0.05).Conclusion The high expression of MDR1 can affect the efflux ability to MTX by up-regulating the expression of P-gp,thus enhancing the drug resistance to MTX in RA FLS.

Enhanced mercuric chloride adsorption onto sulfur-modified activated carbons derived from waste tires.

A number of activated carbons derived from waste tires were further impregnated by gaseous elemental sulfur at temperatures of 400 and 650 degrees C, with a carbon and sulfur mass ratio of 1:3. The capabilities of sulfur diffusing into the micropores of the activated carbons were significantly different between 400 and 650 degrees C, resulting in obvious dissimilarities in the sulfur content of the activated carbons. The sulfur-impregnated activated carbons were examined for the adsorptive capacity of gas-phase mercuric chloride (HgC1) by thermogravimetric analysis (TGA). The analytical precision of TGA was up to 10(-6) g at the inlet HgCl2 concentrations of 100, 300, and 500 microg/m3, for an adsorption time of 3 hr and an adsorption temperature of 150 degrees C, simulating the flue gas emitted from municipal solid waste (MSW) incinerators. Experimental results showed that sulfur modification can slightly reduce the specific surface area of activated carbons. High-surface-area activated carbons after sulfur modification had abundant mesopores and micropores, whereas low-surface-area activated carbons had abundant macropores and mesopores. Sulfur molecules were evenly distributed on the surface of the inner pores after sulfur modification, and the sulfur content of the activated carbons increased from 2-2.5% to 5-11%. After sulfur modification, the adsorptive capacity of HgCl2 for high-surface-area sulfurized activated carbons reached 1.557 mg/g (22 times higher than the virgin activated carbons). The injection of activated carbons was followed by fabric filtration, which is commonly used to remove HgCl2 from MSW incinerators. The residence time of activated carbons collected in the fabric filter is commonly about 1 hr, but the time required to achieve equilibrium is less than 10 min. Consequently, it is worthwhile to compare the adsorption rates of HgCl2 in the time intervals of < 10 and 10-60 min.

1-Cyclo-propyl-6-fluoro-7-(4-nitro-so-piperazin-1-yl)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid.

The title compound, C(17)H(17)FN(4)O(4), is a derivative of ciprofloxacin [1-cyclo-propyl-6-fluoro-4-oxo-7-(1-piperazin-yl)-1,4-dihydro-quinoline-3-carboxylic acid]. The crystal packing is stabilized by inter-molecular C-H⋯O hydrogen bonds together with π-π electron ring inter-actions [centroid-centroid separations between quinoline rings of 3.5864 (11) and 3.9339 (13) Å]. A strong intra-molecular O-H⋯O hydrogen bonds is present as well as an intra-molecular C-H⋯F inter-action.

Effect of antisense oligodeoxynucleotide of telomerase RNA on telomerase activity and cell apoptosis in human colon cancer.

AIM: To explore the effect of antisense oligodeoxynucleotide (As-ODN) of telomerase RNA on telomerase activity and cell apoptosis in human colon cancer. METHODS: As-ODN was transfected into SW480 cells by liposomal transfection reagent. Telomerase activity of SW480 cells was examined by telomeric repeat amplification protocol (TRAP) and enzyme-linked immunosorbent assay (ELISA). Apoptosis was analyzed by morphology and flow cytometry. RESULTS: The telomerase activity in SW480 cells transfected with 1.0 micromol/L of As-ODN for 2-5 days, was significantly decreased in a time-dependent manner, and the cells underwent apoptosis. The missense ODN (Ms-ODN) and the control group transfected with SW480 cells did not show these changes. CONCLUSION: As-ODN can specifically inhibit the telomerase activity of SW480 cells and induce apoptosis.

Telomerase activity and cell apoptosis in colon cancer cell by human telomerase reverse transcriptase gene antisense oligodeoxynucleotide.

AIM: To evaluate the effect of human telomerase reverse transcriptase (hTERT) gene antisense oligodeoxynucleotide (As-ODN) on telomerase activity and cell apoptosis in colon cancer cell line SW480. METHODS: As-ODN was transfected into cells SW480 by liposomal transfection. Cultured cells were divided into three groups: ASODN (5'GGAGCGCGCGGCATCGCGGG-3'), sense oligodeoxynucleotide (5'-CCCGCGATGCCGCGCGCTCC-3', S-ODN) and control. The concentration of oligodeoxynucleotide and liposome was 10 micromol/L and 16 mg/L, respectively. The activity of telomerase was examined by telomeric repeat amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA), and cell apoptosis was observed by morphology and flow cytometry in each group. RESULTS: Telomerase activity began to be down-regulated or inhibited when cells SW480 were treated with As-ODN for 72 h, and cell apoptosis was induced. CONCLUSION: It is suggested that hTERT As-ODN might specially inhibit the activity of telomerase in colon cancer cells and it is further proved that the hTERT gene has a significant correlation with telomerase activity. Further evidence is needed to prove whether hTERT As-ODN is a potential tool for the treatment of colon cancer.