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ABSTRACT: We report that self-assembled gold (Au) nanopyramid arrays can greatly enhance the photocurrent of narrow bandgap organic solar cells using their plasmonic near-field effect. The plasmonic enhanced power conversion efficiency exhibited up to 200% increase under the AM 1.5 solar illumination.
Nanoscale 06/2012; 4(15):4421-5. · 5.91 Impact Factor
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ABSTRACT: Langerhans cell histiocytosis (LCH) is a disorder of clonal proliferation of Langerhans-type cells. The imaging findings of LCH are not specific. A 27-year-old woman was admitted to our hospital because of liver enzyme elevation without other hepatic signs. Radiological studies were originally interpreted as possible metastatic disease to the liver. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) images demonstrated a diffuse pattern of nodules in the liver with hypermetabolic activity. LCH was diagnosed histopathologically with an ultrasound-guided liver biopsy. This case illustrates the importance of considering proliferative/benign conditions of the liver when interpreting PET/CT. Failure to do so could result in patient mismanagement.
Annals of Nuclear Medicine 03/2012; · 1.50 Impact Factor
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ABSTRACT: Plasmonic graphene is fabricated using thermally assisted self-assembly of silver nanoparticles on graphene. The localized surface-plasmonic effect is demonstrated with the resonance frequency shifting from 446 to 495 nm when the lateral dimension of the Ag nanoparticles increases from about 50 to 150 nm. Finite-difference time-domain simulations are employed to confirm the experimentally observed light-scattering enhancement in the solar spectrum in plasmonic graphene and the decrease of both the plasmonic resonance frequency and amplitude with increasing graphene thickness. In addition, plasmonic graphene shows much-improved electrical conductance by a factor of 2-4 as compared to the original graphene, making the plasmonic graphene a promising advanced transparent conductor with enhanced light scattering for thin-film optoelectronic devices.
Advanced Materials 03/2012; 24(10):OP71-6. · 13.88 Impact Factor
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ABSTRACT: Triangular graphene nanoflakes (TGFs), due to their novel magnetic configurations, can serve as building blocks to design new magnetic materials. Based on spin polarized density functional theory, we show that the two dimensional (2D) structures composed of zigzag-edged TGFs linked by 1,3,5-benzenetriyl units (TGF(N)-C(6)H(3)) are ferromagnetic. Their magnetic moments can be tuned by changing the size and edge termination of TGFs, namely magnetic moments increase linearly with the size of TGFs, and double hydrogenation of the edge carbon atoms can significantly enhance stability of the ferromagnetic states. The dynamic stability of the assembled 2D structures is further confirmed by frequency calculations. The characteristic breathing mode is identified where the frequency changes with the inverse square root of the TGFs width, which can be used to identify the size of TGF(N)-C(6)H(3) in Raman experiments. This study provides new pathways to assemble 2D ferromagnetic carbon materials.
Physical Chemistry Chemical Physics 02/2012; 14(6):2065-9. · 3.57 Impact Factor
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Zhonghua zhong liu za zhi [Chinese journal of oncology] 02/2012; 34(2):136-7.
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ABSTRACT: Alcohol dehydrogenases (ADHs) from thermophilic microorganisms are interesting enzymes that have their potential applications in biotechnology and potentially provide insight into the mechanisms of action of thermo-tolerant proteins. The molecular mechanisms of ADHs under thermal stress in vivo have yet to be explored. Herein, we employed a proteomic strategy to survey the possible interactions of secondary-ADH (2-ADH) with other proteins in Thermoanaerobacter tengcongensis (T. tengcongensis) cultured at 75°C and found that 2-ADH, pyruvate-ferredoxin oxidoreductase (PFOR) and several glycolytic enzymes coexisted in a protein complex. Using anion exchange chromatography, the elution profile indicated that the native 2-ADH was present in two forms, PFOR-bound and PFOR-free. Immuno-precipitation and pull down analysis further validated the interactions between 2-ADH and PFOR. The kinetic behaviours of 2-ADH either in the recombinant or native form were evaluated with different substrates. The enzyme activity of 2-ADH was inhibited in a non-competitive mode by PFOR, implying the interaction of 2-ADH and PFOR negatively regulated alcohol formation. In T. tengcongensis, PFOR is an enzyme complex located at the upstream of 2-ADH in the alcohol generation pathway. These findings, therefore, offered a plausible mechanism for how alcohol metabolism is regulated by hetero-interactions between 2-ADH and PFOR, especially in anaerobic thermophiles.
Biochemical and Biophysical Research Communications 01/2012; 417(3):1018-23. · 2.48 Impact Factor
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ABSTRACT: The title compound, C(6)H(5)N(5), is almost planar, the triazole and pyrimidine rings forming a dihedral angle of 2.9 (13)°.
Acta Crystallographica Section E Structure Reports Online 01/2012; 68(Pt 1):o53. · 0.35 Impact Factor
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Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 10/2011; 32(10):699-700.
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ABSTRACT: Protein phosphorylation in bacteria is important for signaling and metabolic activity. Clostridium acetobutyicum can synthesize high yield of organic solvent under acidic condition. How solventogenesis is regulated at molecular level in this bacterium, is not clearly elucidated yet. We used two dimensional electrophoresis (2-DE) and mass spectrometry to have a differential analysis of the bacterial proteins from Clostridium acetobutylicum at acedogenic and solventogenic stage. We focused on these iso-spots with similar molecular mass and different pI values. Totally, eight string spots were identified, which displayed significant changes of pI values as well as spot volumes in response to solventogenic development. The data acquired from mass spectrometry demonstrated that all of the iso-spots contained the phosphrylated peptides. Bioinformatic analysis revealed that these proteins partake in the pathways of solvent synthesis.
Sheng wu gong cheng xue bao = Chinese journal of biotechnology 10/2010; 26(10):1357-62.
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ABSTRACT: Thermoanaerobacter tengcongensis could utilize galactose as a carbon source via the enzymes encoded by a novel gal operon, whose regulation mechanism has yet to be elucidated. We propose here that the gal operon in T. tengcongensis is regulated through a HisK:GalR two-component system. By using radioactive isotope assay and genetic analysis, we found that the kinase of this system, HisK, is phosphorylated by ATP, and the regulator, GalR, accepts a phosphoryl group during phosphorelay, in which the phosphoryl group at HisK-His-259 is transferred to GalR-Asp-56. Two-dimensional electrophoresis, followed by Western blotting, revealed that phosphorylation status of GalR is uniquely dependent on the galactose stimulus in vivo. Furthermore, DNA pulldown assays demonstrated that the phosphorylated GalR prefers binding to the operator DNA O(2), whereas the unphosphorylated GalR to O(1). A model of HisK:GalR is proposed to explain how galactose mediates the expression of the gal operon in T. tengcongensis.
Journal of bacteriology 09/2010; 192(17):4311-6. · 3.94 Impact Factor
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Bo Meng,
Zhong Qian,
Fan Wei,
Weiwei Wang,
Chuanqi Zhou,
Zhuowei Wang,
Quanhui Wang,
Wei Tong, Qian Wang,
Yanhe Ma,
Ningzhi Xu,
Siqi Liu
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ABSTRACT: It is generally accepted that protein complexes play an active role in avoiding the protein degradation of the thermophiles. Thermoanaerobacter tengcongensis was cultured at three different temperatures (55, 75 and 80 degrees C) and the extracts of protein complexes were prepared. Through blue native PAGE, the changes of the relative band volumes in response to different temperatures were semi-quantitatively compared and six temperature-dependent bands were obtained. These bands were excised, digested with trypsin and then analyzed with MS for the identification of protein components. With the combination of the proteins identified by LC MS/MS and MALDI TOF/TOF MS, a total of 92 unique proteins were ascertained in these complexes. Besides, some protein components were examined with Western blot, which gave us insights into the survival mechanism of thermophiles. These included (i) the composition of complex at 80 degrees C was significantly different from that at the other two temperatures; (ii) HSPs presented in all temperature-dependent complexes; (iii) several proteins associated with the functional pathways existed in the same complexes, indicating that the complex structure provided facility for the functional efficiency.
Proteomics 07/2009; 9(11):3189-200. · 4.43 Impact Factor
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ABSTRACT: On the basis of the Thermoanaerobacter tengcongensis genome, a novel type of gal operon was deduced. The gene expression and biochemical properties of this operon were further characterized. RT-PCR analysis of the intergenic regions suggested that the transcription of the gal operon was continuous. With gene cloning and enzyme activity assays, TTE1929, TTE1928 and TTE1927 were identified to be GalT, GalK and GalE, respectively. Results elicited from polarimetry assays revealed that TTE1925, a hypothetical protein, was a novel mutarotase, termed MR-Tt. TTE1926 was identified as a regulator that could bind to two operators in the operon promoter. The transcriptional start sites were mapped, and this suggested that there are two promoters in this operon. Expression of the gal genes was significantly induced by galactose, whereas only MR-Tt expression was detected in glucose-cultured T. tengcongensis at both the mRNA and the protein level. In addition, the abundance of gal proteins was examined at different temperatures. At temperatures ranging from 60 to 80 degrees C, the level of MR-Tt protein was relatively stable, but that of the other gal proteins was dramatically decreased. The operator-binding complexes were isolated and identified by electrophoretic mobility shift assay-liquid chromatography (EMSA-LC) MS-MS, which suggested that several regulatory proteins, such as GalR and a sensory histidine kinase, participate in the regulation of the gal operon.
Microbiology 05/2009; 155(Pt 5):1717-25. · 3.06 Impact Factor
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Quanhui Wang,
Huiming Han,
Yanfen Xue,
Zhong Qian,
Bo Meng,
Fuli Peng,
Zhuowei Wang,
Wei Tong,
Chuanqi Zhou, Qian Wang,
Yonghao Guo,
Gang Li,
Siqi Liu,
Yanhe Ma
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ABSTRACT: Identification of differentially proteomic responses to external pHs would pave an access for understanding of survival mechanisms of bacteria living at extreme pH environment. We cultured Alkalimonas amylolytica N10 (N10), a novel alkaliphilic bacterium found in Lake Chahannor, in media with three different pHs and extracted the correspondent membrane and cytoplasm proteins for proteomic analysis through 2-DE. The differential 2-DE spots corresponding to the altered pHs were delivered to MALDI TOF/TOF MS for protein identification. Since the genomic data of strain N10 was unavailable, we encountered a problem at low rate of protein identification with 18.1%. We employed, therefore, a combined strategy of de novo sequencing to analyze MS/MS signals generated from MALDI TOF/TOF MS. A significantly improved rate of protein identification was thus achieved at over than 70.0%. Furthermore, we extensively investigated the expression of these pH-dependent N10 genes using Western blot and real-time PCR. The conclusions drawn from immunoblot and mRNA measurements were mostly in agreement with the proteomic observations. We conducted the bioinformatic analysis to all the pH-dependent N10 proteins and found that some membrane proteins participated in iron transport were differentially expressed as external pH elevated and most of differential proteins with increased or bell-shape mode of pH-dependence were involved in bioenergetic process and metabolism of carbohydrates, fatty acid, amino acids, and nucleotides. Our data thus provide a functional profile of the pH-responsive proteins in alkaliphiles, leading to elucidation of alkaliphilic-adaptive mechanism.
Proteomics 04/2009; 9(5):1254-73. · 4.43 Impact Factor
