Publications by authors named "Xiaojuan Shen"

19 Publications

  • Page 1 of 1

Comparison of Viromes in Ticks from Different Domestic Animals in China.

Virol Sin 2020 Aug 10;35(4):398-406. Epub 2020 Mar 10.

Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.

Ticks are involved in the transmission of various arboviruses and some tick-borne viruses pose significant threats to the health of humans or livestock. This study aimed to investigate the geographical distribution of tick species and tick-associated viruses in central and eastern China. Total 573 ticks from domestic animals including dogs, sheep and cattle were collected in 2017. Two genera of ticks were identified including Rhipicephalus and Haemaphysalis. Sequencing was performed on Miseq Illumina platform to characterize the tick viromes from the four different sampling locations. Following trimming, 13,640 reads were obtained and annotated to 19 virus families. From these sequences, above 37.74% of the viral reads were related to the RNA viruses. Virome comparison study revealed that the tick viral diversity was considerably different in the two identified tick genera. The viral diversity of R. microplus was significantly different from that of other Rhipicephalus species. On the other hand, substantial overlap in viral species was observed between the same genera. In addition, we found no evidence that the natural host played a major role in shaping virus diversity based on the comparison of their viromes. Rather, the geographic location seems to significantly influence the viral families. Phylogenetic study indicated that the novel negative-sense RNA viruses identified in this study was closely related to Bole tick virus 1 and 3 viruses. In conclusion, the present study provides a baseline for comparing viruses detected in ticks, according to species, natural hosts, and geographic locations.
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http://dx.doi.org/10.1007/s12250-020-00197-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7462941PMC
August 2020

Adult Human Glioblastomas Harbor Radial Glia-like Cells.

Stem Cell Reports 2020 02 30;14(2):338-350. Epub 2020 Jan 30.

Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA. Electronic address:

Radial glia (RG) cells are the first neural stem cells to appear during embryonic development. Adult human glioblastomas harbor a subpopulation of RG-like cells with typical RG morphology and markers. The cells exhibit the classic and unique mitotic behavior of normal RG in a cell-autonomous manner. Single-cell RNA sequencing analyses of glioblastoma cells reveal transcriptionally dynamic clusters of RG-like cells that share the profiles of normal human fetal radial glia and that reside in quiescent and cycling states. Functional assays show a role for interleukin in triggering exit from dormancy into active cycling, suggesting a role for inflammation in tumor progression. These data are consistent with the possibility of persistence of RG into adulthood and their involvement in tumor initiation or maintenance. They also provide a putative cellular basis for the persistence of normal developmental programs in adult tumors.
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http://dx.doi.org/10.1016/j.stemcr.2020.01.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014025PMC
February 2020

Entry of sapelovirus into IPEC-J2 cells is dependent on caveolae-mediated endocytosis.

Virol J 2019 03 25;16(1):37. Epub 2019 Mar 25.

Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China.

Background: Porcine sapelovirus (PSV), a species of the genus Sapelovirus within the family Picornaviridae, are a significant cause of enteritis, pneumonia, polioencephalomyelitis and reproductive disorders in pigs. However, the life cycle of PSV on the molecular level is largely unknown.

Methods: Here, we used chemical inhibitors, RNA interference, and overexpression of dominant negative (DN) mutant plasmids to verify the roles of distinct endocytic pathways involved in PSV entry into porcine small intestinal epithelial cell line (IPEC-J2).

Results: Our experiments indicated that PSV infection was inhibited when cells were pre-treated with NHCl or chloroquine. Inhibitors nystatin, methyl-β-cyclodextrin, dynasore and wortmannin dramatically reduced PSV entry efficiency, whereas the inhibitors chlorpromazine and EIPA had no effect. Furthermore, overexpression caveolin DN mutant and siRNA against caveolin also decreased virus titers and VP1 protein synthesis, whereas overexpression EPS15 DN mutant and siRNA against EPS15 did not reduce virus infection.

Conclusions: Our findings suggest that PSV entry into IPEC-J2 cells depends on caveolae/lipid raft mediated-endocytosis, that is pH-dependent and requires dynamin and PI3K but is independent of clathrin and macropinocytosis.
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http://dx.doi.org/10.1186/s12985-019-1144-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6434631PMC
March 2019

Porcine sapelovirus enters PK-15 cells via caveolae-dependent endocytosis and requires Rab7 and Rab11.

Virology 2019 03 11;529:160-168. Epub 2019 Jan 11.

Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China. Electronic address:

To comprehensively understand the endocytosis of Sapelovirus A (PSV) entry into PK-15 cells, we studied PSV infection in the context of cell perturbations through drug inhibition, siRNA silencing and overexpression of dominant negative (DN) mutants. We showed here that PSV infection of PK-15 cells was unaffected by pretreated with chlorpromazine, EIPA, knockdown of the clathrin heavy chain or overexpression of Eps15 DN mutant. Conversely, PSV infection was sensitive to NHCl, chloroquine, dynasore, nystatin, MβCD and wortmannin with reduced PSV VP1 expression levels and virus titer. Additionally, PSV invasion leaded to rapid actin rearrangement and disruption of the cellular actin network enhanced PSV infection. After internalization the virus was transported to late endosomes and/or cycling endosomes that requires the participation of Rab7 and Rab11. Our findings demonstrate that PSV uses caveolae-dependent endocytosis as the predominant entry portal into PK-15 cells which requires low pH, dynamin, Rab7 and Rab11.
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http://dx.doi.org/10.1016/j.virol.2019.01.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7125664PMC
March 2019

Epidemiological and molecular analysis of avian influenza A(H7N9) virus in Shanghai, China, 2013-2017.

Infect Drug Resist 2018 22;11:2411-2424. Epub 2018 Nov 22.

Department of Animal Science, Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China,

Background: Human infections with a novel avian influenza A virus (H7N9) were reported in Shanghai municipality, China, at the beginning of 2013. High-pathogenic avian influenza (HPAI) H7N9 virus emerged in late February 2017 along with existing low-pathogenic avian influenza (LPAI) H7N9 virus, and this has the potential to develop into a pandemic that could be harmful to humans.

Methods: To elucidate the epidemiological characteristics of H7N9-infected cases from 2013 to 2017 in Shanghai, data on the 59 laboratory-confirmed human cases and 26 bird and environmental contamination cases were collected from the WHO website and Food and Agriculture Organization Emergency Prevention System for Animal Health (FAO EMPRES-AH). Full-length sequences of H7N9 viruses that emerged in Shanghai were collected from the Global Initiative on Sharing Avian Influenza Data to analyze the evolutionary and genetic features.

Results: We found that genetically different strains emerged in every epidemic in Shanghai, and most of the circulating H7N9 strains had affinity to human-type receptors, with the characteristics of high-virulence and low-pathogenic influenza viruses. Furthermore, our findings suggest that the Shanghai chicken strains are closely related to the HPAI H7N9 virus A/Guangdong/17SF003/2016, indicating that this viral strain is of avian origin and generated from the LPAI H7N9 viruses in Shanghai. The gradual decrease in H7N9 human infection in Shanghai was probably due to the control measures taken by the Shanghai government and the enhanced public awareness leading to a reduced risk of H7N9 virus infection. However, LPAI H7N9 viruses from poultry and environmental samples were continually detected in Shanghai across the epidemics, increasing the risk of new emerging H7N9 outbreaks.

Conclusion: It is important to consistently obtain sufficient surveillance data and implement prevention measures against H7N9 viruses in Shanghai municipality.
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http://dx.doi.org/10.2147/IDR.S179517DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6254586PMC
November 2018

Benefits of procyanidins on gut microbiota in Bama minipigs and implications in replacing antibiotics.

J Vet Sci 2018 Nov;19(6):798-807

Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.

Several studies have reported the effect of absorption of procyanidins and their contribution to the small intestine. However, differences between dietary interventions of procyanidins and interventions via antibiotic feeding in pigs are rarely reported. Following 16S rRNA gene Illumina MiSeq sequencing, we observed that both procyanidin administration for 2 months (procyanidin-1 group) and continuous antibiotic feeding for 1 month followed by procyanidin for 1 month (procyanidin-2 group) increased the number of operational taxonomic units, as well as the Chao 1 and ACE indices, compared to those in pigs undergoing antibiotic administration for 2 months (antibiotic group). The genera and were more abundant in the antibiotic group than in the procyanidin-1 and procyanidin-2 groups. Principal component analysis revealed clear separations among the three groups. Additionally, using the online Molecular Ecological Network Analyses pipeline, three co-occurrence networks were constructed; was in a co-occurrence relationship with and and a co-exclusion relationship with and . Furthermore, metabolic function analysis by phylogenetic investigation of communities by reconstruction of unobserved states demonstrated modulation of pathways involved in the metabolism of carbohydrates, amino acids, energy, and nucleotides. These data suggest that procyanidin influences the gut microbiota and the intestinal metabolic function to produce beneficial effects on metabolic homeostasis.
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http://dx.doi.org/10.4142/jvs.2018.19.6.798DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265587PMC
November 2018

Antimicrobial and antioxidant capacity of glucosamine-zinc(II) complex via non-enzymatic browning reaction.

Food Sci Biotechnol 2018 Feb 21;27(1):1-7. Epub 2017 Sep 21.

Institute of Polymer Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang, 212013 Jiangsu Province People's Republic of China.

Coordination compounds play an important role in the life process, and have been widely used in food, cosmetics and pharmaceutical industry. Herein, we have developed a novel kind of glucosamine-zinc(II) complex (GlcN-ZC) for food additive using non-enzymatic browning reaction. The GlcN-ZC was characterized by FTIR and XRD. Moreover, UV absorbance changes, browning intensity, fluorescence changes, antioxidant activity and antimicrobial assessment of GlcN-ZC were also evaluated. Results showed the GlcN-ZC intermediate compounds were accumulated in non-enzymatic browning while prolonging heating time and melanoidins were produced in the final stage. The fluorescence changes confirmed that fluorophores were formed during the non-enzymatic reaction and fluorescence intensity reached a maximun at 60 min. The highest radical scavenging activity of GlcN-ZC formed after 180 min of heating was 79.2%. Furthermore, GlcN-ZC exhibited excellent antibacterial activity against and . . Therefore, GlcN-ZC can be used as a novel promising additive in the food industry.
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http://dx.doi.org/10.1007/s10068-017-0192-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049746PMC
February 2018

Integrated signal probe based aptasensor for dual-analyte detection.

Biosens Bioelectron 2017 Oct 26;96:268-274. Epub 2017 Apr 26.

Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Changsha 410083, Hunan, PR China; College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. Electronic address:

For the multi-analyte detection, although the sensitivity has commonly met the practical requirements, the reliability, reproducibility and stability need to be further improved. In this work, two different aptamer probes labeled with redox tags were used as signal probe1 (sP1) and signal probe2 (sP2), which were integrated into one unity DNA architecture to develop the integrated signal probe (ISP). Comparing with the conventional independent signal probes for the simultaneous multi-analyte detection, the proposed ISP was more reproducible and accurate. This can be due to that ISP in one DNA structure can ensure the completely same modification condition and an equal stoichiometric ratio between sP1 and sP2, and furthermore the cross interference between sP1 and sP2 can be successfully prevented by regulating the complementary position of sP1 and sP2. The ISP-based assay system would be a great progress for the dual-analyte detection. Combining with gold nanoparticles (AuNPs) signal amplification, the ISP/AuNPs-based aptasensor for the sensitive dual-analyte detection was explored. Based on DNA structural switching induced by targets binding to aptamer, the simultaneous dual-analyte detection was simply achieved by monitoring the electrochemical responses of methylene blue (MB) and ferrocene (Fc) This proposed detection system possesses such advantages as simplicity in design, easy operation, good reproducibility and accuracy, high sensitivity and selectivity, which indicates the excellent application of this aptasensor in the field of clinical diagnosis or other molecular sensors.
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http://dx.doi.org/10.1016/j.bios.2017.04.039DOI Listing
October 2017

Improved Work Function of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonic acid) and its Effect on Hybrid Silicon/Organic Heterojunction Solar Cells.

Nanoscale Res Lett 2016 Dec 30;11(1):532. Epub 2016 Nov 30.

College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 215006, People's Republic of China.

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (HPtCl) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to ~20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.
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http://dx.doi.org/10.1186/s11671-016-1759-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5131012PMC
December 2016

How the Sequence of a Gene Specifies Structural Symmetry in Proteins.

PLoS One 2015 7;10(12):e0144473. Epub 2015 Dec 7.

Key Laboratory of Human-Machine Intelligence-Synergy Systems of Chinese Academy of Sciences (CAS), Shenzhen Institutes of Advanced Technology, CAS, Shenzhen, China.

Internal symmetry is commonly observed in the majority of fundamental protein folds. Meanwhile, sufficient evidence suggests that nascent polypeptide chains of proteins have the potential to start the co-translational folding process and this process allows mRNA to contain additional information on protein structure. In this paper, we study the relationship between gene sequences and protein structures from the viewpoint of symmetry to explore how gene sequences code for structural symmetry in proteins. We found that, for a set of two-fold symmetric proteins from left-handed beta-helix fold, intragenic symmetry always exists in their corresponding gene sequences. Meanwhile, codon usage bias and local mRNA structure might be involved in modulating translation speed for the formation of structural symmetry: a major decrease of local codon usage bias in the middle of the codon sequence can be identified as a common feature; and major or consecutive decreases in local mRNA folding energy near the boundaries of the symmetric substructures can also be observed. The results suggest that gene duplication and fusion may be an evolutionarily conserved process for this protein fold. In addition, the usage of rare codons and the formation of higher order of secondary structure near the boundaries of symmetric substructures might have coevolved as conserved mechanisms to slow down translation elongation and to facilitate effective folding of symmetric substructures. These findings provide valuable insights into our understanding of the mechanisms of translation and its evolution, as well as the design of proteins via symmetric modules.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144473PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4671585PMC
June 2016

A Cascade-Reaction Nanoreactor Composed of a Bifunctional Molecularly Imprinted Polymer that Contains Pt Nanoparticles.

Chemistry 2015 May 1;21(20):7532-9. Epub 2015 Apr 1.

School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (P.R. China) http://material.ujs.edu.cn/en/people-view.asp?id=15.

This study was aimed at addressing the present challenge of cascade reactions, namely, how to furnish the catalysts with desired and hierarchical catalytic ability. This issue was addressed by constructing a cascade-reaction nanoreactor made of a bifunctional molecularly imprinted polymer containing acidic catalytic sites and Pt nanoparticles. The acidic catalytic sites within the imprinted polymer allowed one specified reaction, whereas the encapsulated Pt nanoparticles were responsible for another coupled reaction. To that end, the unique imprinted polymer was fabricated by using two well-coupled templates, that is, 4-nitrophenyl acetate and 4-nitrophenol. The catalytic hydrolysis of the former compound at the acidic catalytic sites led to the formation of the latter compound, which was further reduced by the encapsulated Pt nanoparticles to 4-aminophenol. Therefore, this nanoreactor demonstrated a catalytic-cascade ability. This protocol opens up the opportunity to develop functional catalysts for complicated chemical processes.
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http://dx.doi.org/10.1002/chem.201406285DOI Listing
May 2015

Role for gene sequence, codon bias and mRNA folding energy in modulating structural symmetry of proteins.

Annu Int Conf IEEE Eng Med Biol Soc 2013 ;2013:596-9

Structural symmetry in proteins is commonly observed in the majority of fundamental protein folds. Meanwhile, nascent polypeptide chains of proteins have the potential to start the co-translational folding process and this process can have drastic effects on protein structure. Thus we are interested in understanding mechanisms that gene adopts in specifying structural symmetry in proteins. In the present paper, we reveal that for two representative symmetric proteins from (aβ)8-barrel fold and beta-trefoil fold, intragenic symmetry is detected in the corresponding gene sequences. Codon bias and mRNA folding energy might be involved in mediating translation speed for the formation of structural symmetry: at least one major decrease in both codon bias and mRNA folding energy can be observed in the connecting region of the symmetric substructures along the codon sequence. Results suggest that gene duplication and fusion is responsible for structural symmetry in these proteins, and the usage of rare codons or higher order of secondary structure near the boundaries of symmetric substructures might be selected in order to slow down translation speed for effectively co-translational folding process of symmetric proteins.
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http://dx.doi.org/10.1109/EMBC.2013.6609570DOI Listing
July 2015

Low temperature solution-processed high performance photodiode based on Si-ZnO core-shell structure.

Phys Chem Chem Phys 2013 Apr;15(14):4970-4

Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, P R China.

Radial heterojunction photodiodes based on a silicon nanowire arrays (SiNWs)-zinc oxide (ZnO) core-shell structure is demonstrated in this report. The heterojunction can be constructed by spin-coating ZnO nanoparticles onto SiNWs and a low temperature post-annealing process (<270 °C). The photodiode displays typical diode rectifying characteristics with an ideality factor of as low as 1.28, and shows an excellent photoresponse in both visible and near infrared regions in which a peak value of 0.54 A/W at zero bias was attained. The sensitivity is superior to that of previously reported devices fabricated with vacuum-deposition methods. In contrast, the planar silicon-ZnO junction only displays the peak photoresponsivity of 0.34 A/W. The superior performance of radial junction is ascribed to the highlight-harvesting capability, large interfacial area and efficient charge carrier collection arising from the core (SiNWs)-shell (ZnO) structure. Here, high temperature processes are dispensable by using facile solution-processed techniques, which avoid thermal minority lifetime degradation of silicon and simplify the fabrication process of the photodiodes.
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http://dx.doi.org/10.1039/c3cp43083aDOI Listing
April 2013

Robust and aligned carbon nanotube/titania core/shell films for flexible TCO-free photoelectrodes.

Small 2013 Jan 11;9(1):148-55. Epub 2012 Sep 11.

Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, 215123, China.

Carbon nanotube (CNT)/semiconducting oxide hybrids are an ideal architecture for light-harvesting devices, in which the CNTs are expected to not only act as a scaffold but also provide fast transport paths for photogenerated charges in the oxide. However, the current potential of CNTs for charge transport is largely suppressed due to the nanotubes not being interconnected but isolated by the low conductive oxide coatings. Herein, a flexible and conductive CNT/TiO(2) core/shell heterostructure film is reported, with aligned and interconnected CNTs wrapped in a continuous TiO(2) coating. Without using additional transparent conducting oxide (TCO) substrates, this unique feature of the film boosts the incident photon-to-electron conversion efficiency to 32%, outperforming TiO(2) nanoparticle electrodes fabricated on TCO substrates. Moreover, the film shows high structural stability and can generate a stable photocurrent even after being bent hundreds of times.
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http://dx.doi.org/10.1002/smll.201201168DOI Listing
January 2013

Hybrid heterojunction solar cell based on organic-inorganic silicon nanowire array architecture.

J Am Chem Soc 2011 Dec 14;133(48):19408-15. Epub 2011 Nov 14.

Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123, China.

Silicon nanowire arrays (SiNWs) on a planar silicon wafer can be fabricated by a simple metal-assisted wet chemical etching method. They can offer an excellent light harvesting capability through light scattering and trapping. In this work, we demonstrated that the organic-inorganic solar cell based on hybrid composites of conjugated molecules and SiNWs on a planar substrate yielded an excellent power conversion efficiency (PCE) of 9.70%. The high efficiency was ascribed to two aspects: one was the improvement of the light absorption by SiNWs structure on the planar components; the other was the enhancement of charge extraction efficiency, resulting from the novel top contact by forming a thin organic layer shell around the individual silicon nanowire. On the contrary, the sole planar junction solar cell only exhibited a PCE of 6.01%, due to the lower light trapping capability and the less hole extraction efficiency. It indicated that both the SiNWs structure and the thin organic layer top contact were critical to achieve a high performance organic/silicon solar cell.
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http://dx.doi.org/10.1021/ja205703cDOI Listing
December 2011

Conformation and sequence evidence for two-fold symmetry in left-handed beta-helix fold.

Authors:
Xiaojuan Shen

J Theor Biol 2011 Sep 22;285(1):77-83. Epub 2011 Jun 22.

Neural Engineering Center, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen University Town, Nanshan District, Shenzhen 518055, China.

The left-handed beta-helix (LβH) has received interest recently as it folds as a possible solution for the structure of misfolded proteins associated with prion and Huntington's diseases. Through a combination of sequence and structure analysis, we uncover a novel feature that is common to this unique fold: a two-fold symmetry in both sequence and structure, and this feature always coupled with extended loops in the middle of the helix. Since the results reveal a two-fold symmetric pattern both in the sequence and structure, it may indicate that the symmetry in tertiary structure is coded by the symmetry in primary sequence, which agrees with Anfisen's proposal that a protein's amino-acid sequence specify its three-dimensional structure. It may also indicate that LβH adopts a two-fold repeat pattern during the evolution process and symmetry helps maintaining the stability of the helix structure. The two-fold symmetric pattern and extended loops might be important in maintaining stability of helix proteins. This discovery can be useful in understanding the folding mechanisms of this protein fold and provide insights in the relation between sequences and structures.
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http://dx.doi.org/10.1016/j.jtbi.2011.06.011DOI Listing
September 2011

High-performance photoelectrochemical cells from ionic liquid electrolyte in methyl-terminated silicon nanowire arrays.

ACS Nano 2010 Oct;4(10):5869-76

Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, China.

Photoelectrochemical (PEC) cells based on silicon nanowire arrays (SiNWs) have, to date, exhibited modest power conversion efficiency (PCE) and suffered serious degradation, though they exhibit advantageous properties of charge-transfer/transport properties at the radial-junction and strong light-trap capabilities. The main challenge for this low-cost PEC cell is the surface photooxidation and photocorrosion of the silicon surface when contacting with the electrolyte. In this report, SiNWs derivatized with covalently attached methyl groups, prepared via a two-step chlorination/methylation procedure, demonstrate excellent stability even in the presence of water. Furthermore, SiNWs PEC cells utilizing a room temperature ion liquid (IL) acting as an electrolyte solvent display neglectable surface oxidation. A PEC cell based on a platinum (Pt) nanodots decorated and methylated (-CH(3)) SiNWs electrode in combination with an IL electrolyte yields a PCE of 6.0% and shows excellent stability under simulated air mass (AM) 1.5 solar spectrum irradiation, while the PCE of a PEC cell based on planar silicon only exhibits 0.003%. The inherent performance of these structures indicates that a -CH(3) (Pt) SiNWs electrode in combination with an IL is a new approach to develop a high-performance and low-cost solar cell.
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http://dx.doi.org/10.1021/nn101980xDOI Listing
October 2010

1,7-Dihydr-oxy-2,3,4-trimeth-oxy-9H-xanthen-9-one monohydrate from Halenia elliptica.

Acta Crystallogr Sect E Struct Rep Online 2008 Mar 5;64(Pt 4):o651-2. Epub 2008 Mar 5.

The title compound, C(16)H(14)O(7)·H(2)O, possesses a planar three-ring skeleton; its carbonyl, one of the two hydroxy and two of the three methoxy O atoms and the water mol-ecule form hydrogen bonds, giving rise to a layer structure.
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http://dx.doi.org/10.1107/S1600536808004832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2960944PMC
March 2008