| 11. |
- Wang, Thanh, 1979-, et al.
(författare)
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The in vitro estrogenic activities of polyfluorinated iodine alkanes
- 2012
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Ingår i: Journal of Environmental Health Perspectives. - USA : National Institute of Environmental Health Sciences (NIEHS). - 0091-6765 .- 1552-9924. ; 120:1, s. 119-125
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Polyfluorinated iodine alkanes (PFIs) are important intermediates in the synthesis of organic fluoride products. Recently, PFIs have been detected in fluoropolymers as residual raw materials, as well as in the ambient environment.OBJECTIVES: High production volumes and potential environmental releases of PFIs might become a concern, but the exposure risk and toxicity of these chemicals are still unclear. In this study, we investigated the potential estrogenic effects of PFIs.METHODS: We studied the estrogenic effects of fluorinated iodine alkanes (FIAs), fluorinated telomer iodides (FTIs), and fluorinated diiodine alkanes (FDIAs) using the E-screen and MVLN assays and the evaluation of estrogen-responsive genes in MCF-7 cells.RESULTS: FIAs have an iodine atom at one end of the perfluorinated carbon chain. 1-Iodoperfluorohexane (PFHxI) and 1-iodoperfluorooctane (PFOI) promoted the proliferation of MCF-7 cells, induced luciferase activity in MVLN cells, and up-regulated the expression of TFF1 and EGR3. In these assays, other FIAs gave negative responses. FDIAs have an iodine atom at each end of the perfluorinated carbon chain, and all the FDIAs showed estrogenic effects. The estrogenic potencies of FIAs and FDIAs correlate well with the carbon chain length of the chemicals. The optimum chain length for estrogenic effects is six carbons, and then eight and four carbons. All FTIs have a single iodine atom at the end of a partially fluorinated carbon chain. None of the FTIs showed estrogenic effects in the tests.CONCLUSIONS: The estrogenic effects of PFIs are dependent on the structural features of iodine substitution and chain length. This research will be helpful in further understanding the estrogenic effects of perfluorinated compounds.
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| 12. |
- Wen, Chenyu, et al.
(författare)
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Efficient reduction and exfoliation of graphite oxide by sequential chemical reduction and microwave irradiation
- 2014
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 194, s. 71-76
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Tidskriftsartikel (refereegranskat)abstract
- An efficient hybrid method combining chemical reduction and microwave irradiation is used to reduce graphite oxide. The hybrid reduction method achieved a carbon/oxygen ratio of 10.33 which is 2.7 times and 1.4 times higher than those obtained with chemical solution and solid-phase microwave irradiation only methods, respectively. The reduced graphene oxide obtained by the hybrid method had a conductance (1.19 × 104 S/m) 84.2 times higher than that by chemical solution and 15.6 times higher than that by solid-phase microwave irradiation. In addition, we reveal that microwave irradiation removes CO bonds more efficiently than CO bonds.
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| 13. |
- Xu, Peng, et al.
(författare)
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Ultra-shallow junctions formed using microwave annealing
- 2013
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 102:12, s. 122114-
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Tidskriftsartikel (refereegranskat)abstract
- Microwave annealing is shown to be viable for achieving low thermal budget formation of ultra-shallow junctions. Regrowth of a 10 nm thick amorphous Si layer that is generated during a Ge amorphization process prior to BF2 or As dopant implantation proceeds at rates up to 0.53 nm/min for BF2 and up to 0.33 nm/min for As at 370 degrees C. The fraction of electrical activation for implanted dopants is as high as 13% for BF2 and 32% for As with negligible diffusion at 540 degrees C.
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| 14. |
- Zhang, Chen Hui, et al.
(författare)
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EHL properties of polyalkylene glycols and their aqueous solutions
- 2012
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Ingår i: Tribology letters. - : Springer. - 1023-8883 .- 1573-2711. ; 45:3, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- Polyalkylene glycols (PAGs) are a type of synthetic lubricants widely used as compressor lubricants, gear oils, hydraulic fluids, and metal working fluids. The PAGs with typical molecular structure can dissolve in water, which makes it a candidate for the base stock of water-based lubricants. Till now, most of the investigations on the water-based lubrication have focussed on the additives. In this work, the potential of PAGs aqueous solutions to replace water as base stocks has been investigated. Four types of PAGs with different molecular weight and their aqueous solutions with different concentrations were studied to reveal their elastohydrodynamic lubrication (EHL) behavior. It has been found that the PAGs solutions can form EHL film like traditional oils. The film-forming capability depends on the viscosity, the pressure-viscosity coefficient, and the molecular weight of PAGs. The results indicate that the PAGs aqueous solution can be employed as base stocks of water-based lubricant
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| 15. |
- Zhao, Bin
(författare)
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Functional studies of deubiquitinating enzymes
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The attachment of ubiquitin to substrate proteins is a key process in regulating cellular events such as cell cycle progression, signal transduction, differentiation, apoptosis, and the clearance of misfolded or aberrant proteins. Like other post-translational modifications, ubiquitination is also reversible. Deconjugation is performed by a family of cysteine- or metallo-proteases collectively known as deubiquitinating enzymes (DUBs). Approximately 100 putative DUBs have been identified in the human genome but only a minority of them has been functionally characterized. The aim of this thesis has been to study the function of selected DUBs in disease-relevant cellular pathways. Screen of the canonical Wnt-signaling pathway with an RNA interference (RNAi) library targeting the human DUBs identified the ubiquitin-specific protease (USP)-4 as a negative regulator. USP4 interacts with two known components in the pathway: the Nemo like kinase (Nlk) and the T-cell factor 4 (TCF4). NLK promotes nuclear accumulation of USP4 where a subpopulation of TCF4 is a substrate of USP4-dependent deubiquitination. Using a yeast-2 hybrid strategy to search for relevant interactions, we identified the proteasome as a binding partner of USP4. USP4 interacts with the S9 subunit of the 19S regulatory particle (RP) through an N-terminal ubiquitin-like (UBL) domain that resembles, but is functionally distinct from, the UBLs of hHR23a/b and Ubiquilin-1. S9 is as an essential proteasome subunit that may regulate the structural integrity of the 26S complex. Thus, USP4 may play a role in the dynamics of ubiquitination at the proteasome. A bioinformatics strategy was used to search for membrane-associated DUBs. We found that a putative transmembrane domain targets USP19 to the endoplasmic reticulum (ER). USP19 is a target of the unfolded protein response and rescues ERAD substrate from proteasomal degradation. Moreover, USP19 interacts with the E3 ligases seven in absentia homolog (SIAH) 1 and SIAH2 that mediate USP19 ubiquitination and degradation by the proteasome. Bioinformatics and biochemical analysis revealed the presence in USP19 of a SIAH-interacting motif that is found in a subset of SIAH targets and may function as a degradation signal. A non-enzymatic role of USP19 in the regulation of the reposed to hypoxia was suggested by the finding that wild-type and catalytic mutant USP19 interact with the hypoxia-inducible factor-1α (HIF-1α). In the absence of USP19, cells fail to mount a proper response to hypoxia.
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| 16. |
- Zhao, Nale, et al.
(författare)
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A Study on The Traffic Organzations of Ring Road Expressways Under Emergency Stituation
- 2013
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Ingår i: Proceedings of the 16th International Conference Road Safety on Four Continents. - Linköping : Statens väg- och transportforskningsinstitut.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- According to the physical and traffic flow characteristics of ring road expressways, the road section elements classification and numbering have been conducted, and three types of traffic organization such as diversion, evacuation and rescue under emergency situation have been studied. Taking the road section between Hongqitai Bridge and Beiliguan Bridge of Shenyang third ring road expressway as an example, the specific diversion, evacuation and rescue routes have been proposed.
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| 17. |
- Zhao, Y., et al.
(författare)
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Nanocomposite electrode materials for low temperature solid oxide fuel cells using the ceria-carbonate composite electrolytes
- 2012
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 37:24, s. 19351-19356
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature solid oxide fuel cell (LTSOFC, 300-600 °C) is one of the hot areas in recent fuel cell developments. In order to develop high performance LTSOFCs, compatible electrodes are highly demanded. We used NANOCOFC (nanocomposites for advanced fuel cell technology) approach to develop nanocomposite electrodes based on metal oxides Ni-Cu-Zn-oxide and samarium doped ceria (SDC). It was found that the materials consist of individual metal oxide and SDC phase, indicating the material as a composite with a homogenous distribution for all constituent components. Highly homogenous distribution of the particles enhanced the catalyst function for electrode applications in LTSOFC devices. We constructed the devices using the SDC-carbonate nanocomposite (NSDC) as the electrolyte and above as prepared composite as electrodes in a symmetrical configuration. We found that the prepared composite electrodes had good catalytic function for both H2 and O2, to prove its anode and cathode functions. Based on the material properties, the LTSOFC devices have reached a power output more than 730 mW cm-2 at 550 °C.
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| 18. |
- Zhao, Yufeng, et al.
(författare)
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Synthesis of hierarchically porous LiNiCuZn-oxide and its electrochemical performance for low-temperature fuel cells
- 2014
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 39:23, s. 12317-12322
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Tidskriftsartikel (refereegranskat)abstract
- In this work, hierarchically porous composite metal oxide LiNiCuZn-oxide (LNCZO) was successfully synthesized through a sol-gel method with a bio-Artemia cyst shell (AS) as a hard template. The phase and morphology of the products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM). The as-synthesized material was used as symmetrical electrodes, anode and cathode, for the SDC-LiNaCO3 (LNSDC) electrolyte based low temperature solid oxide fuel cell (LTSOFCs), achieving a maximum power density of 132 mW cm(-2) at 550 degrees C. Besides, a single-component fuel cell device was also demonstrated using a mixture of as-prepared LNCZO and ionic conductor LNSDC, and a corresponding peak power output of 155 mW cm(-2) was obtained, suggesting that the hierarchically porous product has high prospective in the single-component fuel cell.
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| 19. |
- Zhao, Zeng-Ren, et al.
(författare)
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Significance of mRNA and Protein Expression of MAC30 in Progression of Colorectal Cancer
- 2011
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Ingår i: Chemotherapy. - Basel : Karger AG. - 0009-3157 .- 1421-9794. ; 57:5, s. 394-401
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Tidskriftsartikel (refereegranskat)abstract
- Background: Meningioma-associated protein (MAC30), first described to be overexpressed in meningiomas, exhibits altered expression in certain human tumors. The aim of our study was to investigate the expression of MAC30 mRNA and its correlation with clinicopathological variables in human colorectal cancer (CRC). Methods: MAC30 mRNA expression was first examined in 55 CRCs, along with the samples from the matched distant normal and adjacent noncancerous tissue by RT-PCR, further verified in 18 CRCs by quantitative RT-PCR. MAC30 protein expression was detected by Western blot in 10 CRCs, and DNA sequencing was performed in 1 case of the paired CRC and the matched noncancerous specimen. MAC30 mRNA expression in two colon cancer cell lines, HCT-116(p53-/-) and HCT-116(p53+/+), was detected by quantitative RT-PCR. Results: The mRNA expression of MAC30 was increased in CRC when compared with distant normal (p < 0.01) and adjacent noncancerous mucosa (p < 0.01). The mean value of MAC30 mRNA expression in the tumor located in the colon was higher than in the rectum (0.677 +/- 0.419 vs. 0.412 +/- 0.162, p = 0.005). As the tumor penetrated the wall of the colon/rectum, MAC30 mRNA expression notably increased in tumors with T3+T4 stage compared to tumors with T1+T2 stage (0.571 +/- 0.364 vs. 0.404 +/- 0.115, p = 0.014). MAC30 protein expression in CRCs was also remarkably elevated compared to the adjacent noncancerous mucosa. There was no mutation in the coding region of the MAC30 gene either in CRC or in the noncancerous mucosa. mRNA expression of p53 was notably decreased in HCT-116(p53-/-) compared to HCT-116(p53+/+), while MAC30 did not vary greatly. Conclusion: The overexpression of MAC30 might be involved in the development and aggressiveness of CRCs, especially in the colon.
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| 20. |
- Zhou, Shuang, et al.
(författare)
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A novel thermometric biosensor for fast surveillance of beta-lactamase activity in milk
- 2013
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Ingår i: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 49, s. 99-104
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Tidskriftsartikel (refereegranskat)abstract
- Regulatory restrictions on antibiotic residues in dairy products have resulted in the illegal addition of beta-lactamase to lower antibiotic levels in milk in China. Here we demonstrate a fast, sensitive and convenient method based on enzyme thermistor (ET) for the surveillance of beta-lactamase in milk. A fixed amount of penicillin G, which is a specific substrate of beta-lactamase, was incubated with the milk sample, and an aliquot of the mixture was directly injected into the ET system to give a temperature change corresponding to the remained penicillin G. The amount of beta-lactamase present in sample was deduced by the penicillin G consumed during incubation. This method was successfully applied to quantify beta-lactamase in milk with the linear range of 1.1-20 U mL(-1) and the detection limit of 1.1 U mL(-1). The recoveries ranged from 93% to 105%, with relative standard deviations (RSDs) below 8%. The stability of the column equipped in ET was also studied, and only 5% decrease of activity was observed after 60 days of use. Compared with the conventional culture-based assay, the advantages of high throughput, timesaving and accurate quantification have made this method an ideal alternative for routine use. (C) 2013 Elsevier B.V. All rights reserved.
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