Multilayer structural determination of the GaAs(1¯1¯1¯)2×2 reconstruction by automated tensor LEED

The multilayer atomic coordinates for the GaAs(1¯ 1¯ 1¯)(2×2) surface have been determined using automated tensor low-energy electron diffraction. The results confirm the As adatom trimer model found by total-energy calculations and scanning tunneling microscopy studies although details of the displacements are different. The low-energy electron diffraction analysis, being sensitive to multilayer spacings in the surface region, shows that substantial subsurface relaxations are present.published_or_final_versio

Breathers and rogue waves for a third order nonlocal partial differential equation by a bilinear transformation

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Nanocomposite field effect transistors based on zinc oxide/polymer blends

The authors have examined the field effect behavior of nanocomposite field effect transistors containing ZnO (zinc oxide) tetrapods or nanocrystals dispersed in a polymer matrix of poly[2-methoxy,5-(2-ethylhexyloxy)-1,4- phenylenevinylene] (MEH-PPV). The electrical characteristics of ZnO tetrapods/MEH-PPV composite devices exhibit an increase in hole mobility up to three orders of magnitude higher than the polymer MEH-PPV device. © 2007 American Institute of Physics.published_or_final_versio

Genetic diversity among Toxoplasma gondii isolates from different hosts and geographical locations revealed by analysis of ROP13 gene sequences

Toxoplasma gondii can infect almost all the warm-blooded animals and human beings, causing serious public health problems and economic losses worldwide. Rhoptry protein 13 (ROP13) plays some roles in the invasion process of T. gondii. In this study, sequence variation in ROP13 gene among 14 T. gondii isolates from different geographical locations and hosts was examined. The ROP13 gene was amplified from individual isolates and sequenced. Results show that the length of the ROP13 sequences was 1203 bp. In total, there were 44 variable nucleotide positions in the ROP13 sequences, and sequence variations were 0.1 to 2.0% among the 14 examined T. gondii isolates, representing higher rate in transversion than in transition. Intra-specific nucleotide variations were mainly at the second codon positions. Phylogenetic analysis of the 14 examined T. gondii isolates indicate that the ROP13 sequence was not a suitable genetic marker to differentiate T. gondii isolates of different genotypes from different hosts and geographical regions. Low variation in ROP13 gene sequence may suggest that ROP13 gene could represent a good vaccine candidate against toxoplasmosis.Key words: Toxoplasma gondii, toxoplasmosis, rhpotry protein 13 (ROP13), sequence variation, phylogenetic analysis

Clinical relevance and therapeutic potential of angiopoietin-like protein 4 in hepatocellular carcinoma

published_or_final_versio

Influence of reconstruction on the structure of self-assembled normal-alkane monolayers on Au(111) surfaces

Ordered normal-alkane monolayers of lamellar structures are found to form in the interface between alkane solutions and the reconstructed Au (111) surfaces. The boundaries of the lamellae may exhibit a zigzag shape. In the alkane monolayers, two kinds of packing of the alkane molecules are observed. The packing patterns are correlated to the structure of the gold surface and the molecular lengths of the alkanes. The orientation of alkane molecules is gently disturbed by the reconstructed gold ridges. Furthermore, the lamellar boundaries are located on the elbow positions of the reconstructed gold surfaces for long-chain alkanes. These results demonstrate that the structures of self-assembled monolayers of normal alkanes are sensitive to the structures of the Au (111) surfaces

Bis(diisopropylammonium) dimethyldioxalatostannate

The six-coordinate Sn atom in bis(diisopropylammonium) dimethyldioxalatostannate, [(C3H7)(2)NH2](2)(+) [(CH3)(2)Sn(O2CCO2)](2-), exists in a cis-C2SnO4 coordination sphere [Sn-C 2.127 (5) Angstrom; C-Sn-C 109.2 (3)degrees]. The anion lies on a special position of 2 symmetry. The ammonium cations and the stannate anions are linked by hydrogen bonds into a linear chain

Bis(diisopropylammonium) diphenyldioxalatostannate(IV)

The six-coordinate Sn atom in bis(diisopropylammonium) diphenyldioxalatostannate(IV), [(C3H7)(2)NH2](2)(+) [(C6H5)(2)Sn(O2CCO2)](2-), exists in a cis-C2SnO4 octahedral coordination sphere [Sn-C 2.139 (7) and 2.144 (7) Angstrom; C-Sn-C 103.8 (3)degrees]. The ammonium cations and the stannate anions are linked by hydrogen bonds into a zigzag chain, running along the c axis of the monoclinic cell