bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of in-plane anisotropic strains on the dielectric and pyroelectric properties of Ba0.7Sr0.3TiO3 thin films
Authors: Cao Hai-Xia , Lo Veng Cheong , Li Zhen-Ya
Published: January 2007

A modified Landau-Devonshire phenomenological thermodynamic theory is used to describe the influence of in-plane anisotropic strains on the dielectric and pyroelectric properties of epitaxial Ba0.7Sr0.3TiO3 thin films grown on dissimilar tetragonal substrates. The in-plane anisotropic strain factor-temperature phase diagram is developed. The in-plane anisotropic strains play a crucial role in the dielectric and pyroelectric properties of BST thin films. The theoretical maximum dielectric tunability approaching 100% can be attained at the critical anisotropic strain factor corresponding to the structural phase transformation from ca1 to a1 phase. Moreover, the anisotropic strain factor has an opposite effect on the figure of merit and pyroelectric coefficient, respectively. Furthermore, in the case of isotropic strains, our theoretical results are well consistent with the experimental results.
Ge
1
−
y
Sn
y
∕
Si
(
100
)
composite substrates for growth of InxGa1−xAs and GaAs1−xSbx alloys
Authors: Roucka Radek , Tolle John , Forrest Brandon , Kouvetakis John , D’Costa Vijay R. , Menéndez José
Published: January 2007

We describe unique methodologies for integration of InxGa1−xAs and GaAs1−xSbx semiconductor alloys with Si involving an innovative buffer layer approach based on lattice-engineered Ge1−ySny alloys. These are grown strain-free on Si(100) via formation of Lomer edge dislocations and exhibit a continuous selection of lattice parameters higher than that of Ge. This allows close lattice matching with the InxGa1−xAs and GaAs1−xSbx compounds, thereby providing a manifestly different approach to the integration of mismatched III-V semiconductors with silicon. A series of compositions across the entire alloy range were grown for both systems using metal organic chemical vapor deposition at low temperatures between 500–550°C. The materials displayed high quality morphological, structural, and optical properties as evidenced by Rutherford backscattering spectroscopy, ion channeling, cross sectional transmission electron microscopy, atomic force microscopy, and photoluminescence characterizations. High resolution x-ray diffraction measurements indicated that the films grow with much less strain than those grown on conventional substrates.
Realization and electrical characterization of ultrathin crystals of layered transition-metal dichalcogenides
Authors: Ayari Anthony , Cobas Enrique , Ogundadegbe Ololade , Fuhrer Michael S.
Published: January 2007

Ultrathin crystals of the layered transition-metal dichalcogenide MoS2 (semiconducting) and TaS2 (metallic) were obtained by mechanical peeling or chemical exfoliation techniques and electrically contacted using electron-beam lithography. The MoS2 devices showed high field-effect mobility in the tens of cm2∕Vs and an on/off ratio higher than 105. The TaS2 devices remained metallic despite the fabrication process and showed an enhancement of the superconducting transition temperature and disappearance of the charge density wave phase anomaly at low temperature.
Electron holography of single-crystal iron nanorods encapsulated in carbon nanotubes
Authors: Fujita Takeshi , Chen Mingwei , Wang Xiaomin , Xu Bingshe , Inoke Koji , Yamamoto Kazuo
Published: January 2007

α - Fe nanorods encapsulated in multiwall carbon nanotubes (CNTs) were characterized by x-ray diffraction (XRD), high resolution electron microscopy (HREM), and electron holography. HREM observations revealed that the α-Fe nanoparticles were single crystals with a preferential growth direction of ⟨200⟩α-Fe oriented along CNTs. Phase distributions of an α-Fe nanorod were measured by electron holography and the remanent state was retrieved by a three-dimensional morphological model and an algorithm with the consideration of irregular nanoparticle shape. It was found that the saturated magnetization of the α-Fe nanorod with a CNT outer shell was very close to that of bulk pure α-Fe, suggesting that the core-shell nanostructure effectively prevented the surface oxidation that had been found to significantly degrade the magnetic properties of nanostructured α-Fe.
Gas flow near a plate oscillating longitudinally with an arbitrary frequency
Authors: Sharipov Felix , Kalempa Denize
Published: January 2007

A gas flow near a longitudinally oscillating plate is considered on the basis of the kinetic equation. It is assumed that the oscillation is fully established and the dependence of the solution on the time is harmonic, while its dependence on the spatial coordinate is obtained numerically. The main parameter determining the problem solution is the ratio of intermolecular collision frequency to the oscillation frequency. Moreover, the solution depends on the gas-surface interaction law. To take into account a nondiffuse scattering of particles on the surface the Cercignani-Lampis scattering kernel is applied in the boundary conditions. The numerical calculations were carried out for a wide range of the frequency ratio and for several values of the accommodation coefficients. Two numerical methods were employed to solve the kinetic equation: the integro-moment method and the discrete velocity one. The results obtained by both methods are in a good agreement with each other.
Effect of nuclear motion on the absorption spectrum of dipicolinic acid
Authors: Sauer Petra , Rostovtsev Yuri , Allen Roland E.
Published: January 2007

Using semiclassical electron-radiation-ion dynamics, the authors have examined the effect of nuclear motion, resulting from both finite temperature and the response to a radiation field, on the line broadening of the excitation profile of 2,6-pyridinedicarboxylic acid (dipicolinic acid). With nuclei fixed, there is a relatively small broadening associated with the finite time duration of an applied laser pulse. When the nuclei are allowed to move, the excitation spectrum exhibits a much larger broadening, and is also reduced in height and shifted toward lower frequencies. In both cases, the excitation is due to well-defined π to π* transitions. The further inclusion of thermal motion at room temperature broadens the linewidth considerably because of variations in the molecular geometry: Transitions that had zero or negligible transition probabilities in the ground state geometry are weakly excited at room temperature.
Nonlinear signal mixing in a three-terminal molecular wire
Authors: Liu Christopher , Speyer Joe , Ovchinnikov Igor V. , Neuhauser Daniel
Published: January 2007

The authors study the electronic response of two simple molecular devices to a bichromatic field, where the device acts as a mixer. Two closely related model systems are considered: one is a benzene molecule and the other is a single grapheme sheet, and in both cases the systems are connected to three polyacetylene chains. The electronic response to the dichromatic alternating electric fields is studied by following the electron density fluctuation along the chain lengths. In both cases the electron transfer follows the field frequency at low electric fields. At higher amplitude, a significant amount of nonlinear mixing resulting in new combinations of the input frequencies is found in the spectrum. The influence of gating on the output frequencies is also shown.
Influence of electromagnetic oscillating two-stream instability on the evolution of laser-driven plasma beat-wave
Authors: Gupta D. N. , Singh K. P. , Suk H.
Published: January 2007

The electrostatic oscillating two-stream instability of laser-driven plasma beat-wave was studied recently by Gupta et al. [Phys. Plasmas 11, 5250 (2004)], who applied their theory to limit the amplitude level of a plasma wave in the beat-wave accelerator. As a self-generated magnetic field is observed in laser-produced plasma, hence, the electromagnetic oscillating two-stream instability may be another possible mechanism for the saturation of laser-driven plasma beat-wave. The efficiency of this scheme is higher than the former.
Efficient, single-layer molecular organic light-emitting diodes
Authors: Lane Paul A. , Kushto Gary P. , Kafafi Zakya H.
Published: January 2007

The authors demonstrate efficient molecular organic light-emitting diodes that use direct hole injection from poly(3,4-ethylene-dioxythio-phene):poly(styrene-sulfonate) into a single layer of tris(8-hydroxyquinoline) aluminum (III) for carrier transport and electroluminescence. Single-layer devices have a lower operating bias and higher luminous power efficiency than conventional bilayer devices with a 4,4-bis[N-1-napthyl-N-phenyl-amino]biphenyl hole transport layer. The current density-voltage characteristics of single-layer devices follow Schottky-Richardson behavior and are consistent with an Ohmic contact at the anode.
Performance enhancement of n-channel impact-ionization metal-oxide-semiconductor transistor by strain engineering
Authors: Toh Eng-Huat , Wang Grace Huiqi , Lo Guo-Qiang , Chan Lap , Samudra Ganesh , Yeo Yee-Chia
Published: January 2007

The introduction of lattice strain in impact-ionization metal-oxide-semiconductor (I-MOS) transistors for performance enhancement is reported. Lattice strain affects impact ionization and its impact on device performance is explained in relation to the physics of I-MOS device operation. By integrating epitaxial silicon-carbon (Si0.99C0.01) source and drain regions in a complementary-MOS-compatible fabrication process, strained n-channel I-MOS devices were fabricated. Tensile strain in the channel and impact-ionization regions contributes to enhanced electron transport and device characteristics. The strained I-MOS technology demonstrates an excellent subthreshold swing of 5.3mV∕decade at room temperature. Compared to control I-MOS devices with Si raised source/drain, strained I-MOS devices show significantly higher drive current and a steeper subthreshold swing.
Highly efficient near-infrared organic excimer electrophosphorescent diodes
Authors: Cocchi M. , Virgili D. , Fattori V. , Williams J. A. G. , Kalinowski J.
Published: January 2007

The authors report the fabrication of very high efficiency near-infrared (NIR) organic light-emitting diodes (LEDs) based on a series of terdentate cyclometallated phosphorescent Pt(II) complexes PtLCl as the emitting layer. The LEDs exhibit exclusive NIR excimeric phosphorescence peaking between 705 and 720nm for three different organic ligands (L). Due to the high excimer emission quantum yields of these Pt complexes and to confinement of the recombination zone within the emission layer, unusually high external quantum efficiencies from 9.8% to 10.7% photons/electron and a high forward light output exceeding 15mW∕cm2 were achieved.
Self-propagation of an electrode in leaky dielectrics and its possible relation to bacterial flagellar motors
Authors: Yarin A. L.
Published: January 2007

In this letter, the origin of a force resulting in steady-state propagation of a spherical electrode in a leaky dielectric is explained and the force is calculated. The phenomenon of self-propagation begins from a perturbation in any direction resulting in the electrode motion in that direction. After that, the process sustains itself and a macroscopic electrode moves in the direction of the initial perturbation with a constant velocity U proportional to the potential difference ΔV applied to the system. Microscopic electrodes and bacterial flagellar motors should move with a velocity U∼(ΔV)2. The predicted velocities agree fairly well with the experimental data.
Study of the structural evolution within polystyrene and polystyrene-gold composite colloidal crystals by atomic force microscopy and scanning electron microscopy
Authors: Badilescu Simona , Hajiaboli Ahmad-Reza , Seirafianpour Nader , Sadeghian Ramin Banan , Kahrizi Mojtaba , Truong Vo-Van
Published: January 2007

The simultaneous presence of hexagonal and quadratic arrangements of polystyrene microspheres in the top layers of polystyrene and gold-polystyrene composite colloidal crystals has been evidenced by both atomic force microscopy and scanning electron microscopy. It is thought that the formation of layers with the two different packing modes is in agreement with the phase transformations found in systems with confined geometries. The results of this study are relevant to the fabrication of high quality photonic crystals.
Dielectric abnormities of complex perovskite Ba(Fe1∕2Nb1∕2)O3 ceramics over broad temperature and frequency range
Authors: Wang Z. , Chen X. M. , Ni L. , Liu X. Q.
Published: January 2007

Dielectric characteristics of Ba(Fe1∕2Nb1∕2)O3 ceramics were investigated over a broad temperature and a frequency range. Two dielectric relaxations following Arrhenius law were observed at 150–400 and 406–650K. An extremely high relaxorlike dielectric peak (202 270 at 5Hz, 91 930 at 1kHz, and 37 030 at 100kHz) with very strong frequency dispersion was observed at 406–650K, and it was not relaxor ferroelectric but an oxygen defect induced dielectric abnormity. The significant drop of dielectric constant at 146–400K was also frequency dependent, and it was nearly a Debye relaxation. Between these two dielectric relaxations, there was a frequency dependent dielectric constant plateau over a wide temperature interval.
Defect-induced loading of Pt nanoparticles on carbon nanotubes
Authors: Kim Sung Jin , Park Yong Jin , Ra Eun Ju , Kim Ki Kang , An Kay Hyeok , Lee Young Hee , Choi Jae Young , Park Chan Ho , Doo Seok Kwang , Park Min Ho , Yang Cheol Woong
Published: January 2007

Carbon nanotubes-supported Pt nanoparticles were loaded using a microwave oven on the defective carbon nanotubes generated by an additional oxidant during acid treatment. The authors’ Raman spectra and x-ray diffraction analysis demonstrated that defects created during oxidation and microwave treatment acted as nucleation seeds for Pt adsorption. The generated Pt nanoparticles had the size distributions of 2–3nm and were uniformly distributed on the defects of carbon nanotubes. The authors’ density functional calculations showed that the adsorption of Pt atom on the vacancy of nanotube was significantly stronger by s-p hybridization with carbon atoms near the defect site.
Structural transformation of ZnO nanostructures
Authors: Zhang Lixin , Huang Hanchen
Published: January 2007

Many nanostructures experience structural transformation, either from one type of crystalline structure to another or from one orientation to another orientation within the same crystalline structure. Using a combination of ab initio calculations and analytical formulation, the authors show that such structural transformation is a direct result of surface reconstruction. In particular, the ab initio results show that infinite large ZnO nanoplates and infinite long ZnO nanowires transform from wurtzite to graphitic structure below a critical thickness or diameter. The analytical formulation further shows that nanowires of finite length can go through the same structural transformation at larger critical diameters.
Large area mass analyzer instrument for the chemical analysis of interstellar dust particles
Authors: Sternovsky Z. , Amyx K. , Bano G. , Landgraf M. , Horanyi M. , Knappmiller S. , Robertson S. , Grün E. , Srama R. , Auer S.
Published: January 2007

A new instrument to analyze the chemical composition of dust particles in situ in space has been developed. The large target area (∼0.2m2) makes this instrument well suited for detecting a statistically significant number of interstellar dust grains or other dust particles with a low flux. The device is a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential. The instrument analyzes the ions from the impact generated plasma due to hypervelocity dust impacts onto a solid target surface. The SIMION ion optics software package is used to investigate different potential field configurations and optimize the mass resolution and focusing of the ions. The cylindrically symmetric instrument operates with six ring electrodes and six annular electrodes biased to different potentials to create the potential distribution of the reflectron. The laboratory model of the instrument has been fabricated and tested. Hypervelocity dust impacts are simulated by laser ablation using a frequency doubled Nd:YAG laser with ∼8ns pulse length. The experimental data show typical mass resolution m∕Δm≈200.
Energy quantization of chaos with the semiclassical phases alone
Authors: Takatsuka Kazuo , Takahashi Satoshi , Koh Yang Wei , Yamashita Takefumi
Published: January 2007

The mechanism of energy quantization is studied for classical dynamics on a highly anharmonic potential, ranging from integrable, mixed, and chaotic motions. The quantum eigenstates (standing waves) are created by the phase factors (the action integrals and the Maslov index) irrespective of the integrability, when the amplitude factors are relatively slowly varying. Indeed we show numerically that the time Fourier transform of an approximate semiclassical correlation function in which the amplitude factors are totally removed reproduces the spectral positions (energy eigenvalues) accurately in chaotic regime. Quantization with the phase information alone brings about dramatic simplification to molecular science, since the amplitude factors in the lowest order semiclassical approximation diverge exponentially in a chaotic domain.
Growth of very-high-mobility AlGaSb∕InAs high-electron-mobility transistor structure on si substrate for high speed electronic applications
Authors: Lin Y. C. , Yamaguchi H. , Chang E. Y. , Hsieh Y. C. , Ueki M. , Hirayama Y. , Chang C. Y.
Published: January 2007

The growth of the AlGaSb∕InAs high-electron-mobility transistor (HEMT) epitaxial structure on the Si substrate is investigated. Buffer layers consisted of UHV/chemical vapor deposited grown Ge∕GeSi and molecular beam epitaxy-grown AlGaSb∕AlSb∕GaAs were used to accommodate the strain induced by the large lattice mismatch between the AlGaSb∕InAs HEMT structure and the Si substrate. The crystalline quality of the structure grown was examined by x-ray diffraction, transmission electron microscopy, and atomic force microscopy. Finally, very high room-temperature electron mobility of 27300cm2∕Vs was achieved. It is demonstrated that a very-high-mobility AlGaSb∕InAs HEMT structure on the Si substrate can be achieved with the properly designed buffer layers.
Combinatorial approach for ferroelectric material libraries prepared by liquid source misted chemical deposition method
Authors: Kim Ki Woong , Jeon Min Ku , Oh Kwang Seok , Kim Tai Suk , Kim Yun Seok , Woo Seong Ihl
Published: January 2007

Combinatorial approach for discovering novel functional materials in the huge diversity of chemical composition and processing conditions has become more important for breakthrough in thin film electronic and energy-conversion devices. The efficiency of combinatorial method depends on the preparation of a reliable high-density composition thin-film library. The physico-chemical properties of each sample on the library should be similar to those of the corresponding samples prepared by one-by-one conventional methods. We successfully developed the combinatorial liquid source misted chemical deposition (LSMCD) method and demonstrated its validity in screening the chemical composition of Bi
3.75
La
x
Ce
0.25-x
Ti
3
O
12
(BLCT) for high remanent polarization (
P
r
). LSMCD is a cheap promising combinatorial screening tool. It can control the composition up to ppm level and produce homogeneous multicomponent library. LSMCD method allows us to prepare BLCT thin-film library at the variation of 0.4 mol% of La. Maximum 2
P
r
is 35 μC/cm
−2
at
x
= 0.21. The intensity of (117) XRD peak is quantitatively related to 2
P
r
. Newly developed scanning piezoelectric deformation measurement for nano-sized samples using scanning probe microscope (SPM) is also found out to be reliable for determining the relative ranking of
P
r
value rapidly.
Geobacter pickeringii sp. nov., Geobacter argillaceus sp. nov. and Pelosinus fermentans gen. nov., sp. nov., isolated from subsurface kaolin lenses
Authors: Shelobolina Evgenya S. , Nevin Kelly P. , Blakeney-Hayward Jessie D. , Johnsen Claudia V. , Plaia Todd W. , Krader Paul , Woodard Trevor , Holmes Dawn E. , VanPraagh Catherine Gaw , Lovley Derek R.
Published: January 2007

The goal of this project was to isolate representative Fe(III)-reducing bacteria from kaolin clays that may influence iron mineralogy in kaolin. Two novel dissimilatory Fe(III)-reducing bacteria, strains G12T and G13T, were isolated from sedimentary kaolin strata in Georgia (USA). Cells of strains G12T and G13T were motile, non-spore-forming regular rods, 1–2 μm long and 0.6 μm in diameter. Cells had one lateral flagellum. Phylogenetic analyses using the 16S rRNA gene sequence of the novel strains demonstrated their affiliation to the genus Geobacter. Strain G12T was most closely related to Geobacter pelophilus (94.7 %) and Geobacter chapellei (94.1 %). Strain G13T was most closely related to Geobacter grbiciae (95.3 %) and Geobacter metallireducens (95.1 %). Based on phylogenetic analyses and phenotypic differences between the novel isolates and other closely related species of the genus Geobacter, the isolates are proposed as representing two novel species, Geobacter argillaceus sp. nov. (type strain G12T=ATCC BAA-1139T=JCM 12999T) and Geobacter pickeringii sp. nov. (type strain G13T=ATCC BAA-1140T=DSM 17153T=JCM 13000T). Another isolate, strain R7T, was derived from a primary kaolin deposit in Russia. The cells of strain R7T were motile, spore-forming, slightly curved rods, 0.6×2.0–6.0 μm in size and with up to six peritrichous flagella. Strain R7T was capable of reducing Fe(III) only in the presence of a fermentable substrate. 16S rRNA gene sequence analysis demonstrated that this isolate is unique, showing less than 92 % similarity to bacteria of the Sporomusa–Pectinatus–Selenomomas phyletic group, including ‘Anaerospora hongkongensis’ (90.2 %), Acetonema longum (90.6 %), Dendrosporobacter quercicolus (90.9 %) and Anaerosinus glycerini (91.5 %). On the basis of phylogenetic analysis and physiological tests, strain R7T is proposed to represent a novel genus and species, Pelosinus fermentans gen. nov., sp. nov. (type strain R7T=DSM 17108T=ATCC BAA-1133T), in the Sporomusa–Pectinatus–Selenomonas group.
Terribacillus saccharophilus gen. nov., sp. nov. and Terribacillus halophilus sp. nov., spore-forming bacteria isolated from field soil in Japan
Authors: An Sun-Young , Asahara Mika , Goto Keiichi , Kasai Hiroaki , Yokota Akira
Published: January 2007

Three strains, 002-048T, RB589 and 002-051T, isolated from field soil in Japan, were characterized using a polyphasic approach. The isolates were Gram-positive, strictly aerobic, non-motile rods that formed ellipsoidal, subterminal endospores. The chemotaxonomic characteristics of these isolates included the presence ofmeso-diaminopimelic acid as the cell-wall peptidoglycan, anteiso-C15 : 0and anteiso-C17 : 0as the major cellular fatty acids and MK-7 as the predominant menaquinone. The DNA G+C content was 44–46 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the isolates represented an independent lineage that is distinct from related taxa and exhibited less than 94.3 % sequence similarity with respect to those taxa. Moreover, a DNA–DNA hybridization analysis showed that the three isolates represented two species. On the basis of their phenotypic and phylogenetic distinctiveness, the isolates represent two species within a novel genus, for which the namesTerribacillus saccharophilusgen. nov., sp. nov. andTerribacillus halophilussp. nov. are proposed. The type strain ofT. saccharophilusis 002-048T(=IAM 15309T=KCTC 13936T) and the type strain ofT. halophilusis 002-051T(=IAM 15310T=KCTC 13937T).
Haladaptatus paucihalophilus gen. nov., sp. nov., a halophilic archaeon isolated from a low-salt, sulfide-rich spring
Authors: Savage Kristen N. , Krumholz Lee R. , Oren Aharon , Elshahed Mostafa S.
Published: January 2007

Two novel strains of halophilic archaea, DX253Tand GY252, were isolated from Zodletone Spring, a low-salt, sulfide- and sulfur-rich spring in south-western Oklahoma, USA. The cells were cocci or coccobacilli and occurred singly or in pairs. The two strains grew in a wide range of salt concentrations (0.8–5.1 M) and required at least 5 mM Mg2+for growth. The pH range for growth was 5–7.5 and the temperature range was 25–45 °C. In addition to having the capacity to grow at relatively low salt concentrations, cells remained viable in distilled water after prolonged incubation. The two diether phospholipids that are typical of members of the orderHalobacteriales, phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, were present. Phosphatidylglycerol sulfate and two unidentified glycolipids were also detected. Each strain had two distinct 16S rRNA gene sequences that were only 89.5–90.8 % similar to sequences from the most closely related cultured and recognized species within the orderHalobacteriales. The DNA G+C content of the type strain was found to be 60.5 mol%. The closest relatives were clones and uncharacterized isolates obtained from coastal salt-marsh sediments with salinities equivalent to that of seawater. The physiological, biochemical and phylogenetic differences between strains DX253Tand GY252 and other previously described genera of extremely halophilic archaea suggest that these novel strains represent a novel species and genus within the familyHalobacteriaceae, for which the nameHaladaptatus paucihalophilusgen. nov., sp. nov. is proposed. The type strain is DX253T(=JCM 13897T=DSM 18195T=ATCC BAA-1313T=KCTC 4006T).
Burkholderia soli sp. nov., isolated from soil cultivated with Korean ginseng
Authors: Yoo Seung-Hee , Kim Byung-Yong , Weon Hang-Yeon , Kwon Soon-Wo , Go Seung-Joo , Stackebrandt Erko
Published: January 2007

A polyphasic study was carried out to clarify the taxonomic position of a Gram-negative bacterium isolated from soil cultivated with Korean ginseng in the Eumseong region of Korea. The novel strain, GP25-8T, grew optimally at pH 6–7, 28 °C and 0–1 % NaCl (w/v). The major fatty acids were C18 : 1
ω7c, summed feature 3 (C16 : 1
ω7c/C15 : 0 iso 2-OH) and C16 : 0 (together representing 71.2 % of the total). The 16S rRNA gene sequence similarities between strain GP25-8T and members of the genus Burkholderia ranged from 94.7 to 97.4 %, indicating that this novel strain was phylogenetically related to members of that genus. The novel strain showed the highest sequence similarities to Burkholderia caryophylli ATCC 25418T (97.4 %) and Burkholderia phenazinium LMG 2247T (97.2 %); the levels of DNA–DNA hybridization with these strains were 28 and 12 %, respectively. These results support the conclusion that strain GP25-8T represents a novel species within the genus Burkholderia, for which the name Burkholderia soli sp. nov. is proposed. The type strain is GP25-8T (=KACC 11589T=DSM 18235T).
Micrococcus flavus sp. nov., isolated from activated sludge in a bioreactor
Authors: Liu Xing-Yu , Wang Bao-Jun , Jiang Cheng-Ying , Liu Shuang-Jiang
Published: January 2007

Bacterial strain LW4T was isolated from activated sludge of a wastewater-treatment bioreactor. Cells of strain LW4T were Gram-positive cocci, with a diameter of 0.7–1.0 μm. Colonies produced on LB agar plates were yellow, smooth, circular and 0.5–1.5 mm in diameter. Strain LW4T was aerobic and grew over the temperature range 26–34 °C and pH range 5–9, with optimal growth at 30.5–31.5 °C and pH 6.0–6.2. The cell-wall peptidoglycan of strain LW4T contained amino acid residues of lysine, glutamic acid, alanine, glycine and aspartic acid. The most abundant cellular fatty acids of strain LW4T were anteiso-C15 : 0 (32.15 %) and iso-C15 : 0 (31.65 %). Major respiratory quinones were MK-8(H2) (57.3 %) and MK-7(H2) (32.9 %). The DNA G+C content was 71.4 mol% (T
m). 16S rRNA gene sequence analysis indicated that strain LW4T was phylogenetically related to members of the genus Micrococcus, with similarities ranging from 96.5 to 97.3 %. Levels of DNA–DNA relatedness of strain LW4T to Micrococcus luteus DSM 20030T, Micrococcus lylae DSM 20315T and Micrococcus antarcticus AS 1.2372T were 55, 48 and 36 %, respectively. Based on these results, it is concluded that strain LW4T represents a novel species of the genus Micrococcus, for which the name Micrococcus flavus sp. nov. is proposed. The type strain is strain LW4T (=CGMCC 1.5361T=JCM 14000T).
Shewanella psychrophila sp. nov. and Shewanella piezotolerans sp. nov., isolated from west Pacific deep-sea sediment
Authors: Xiao Xiang , Wang Peng , Zeng Xiang , Bartlett Douglas Hoyt , Wang Fengping
Published: January 2007

TwoShewanella-like bacterial strains, WP2Tand WP3T, which were isolated from west Pacific deep-sea sediment, were studied to determine their taxonomic position. Cells of the two bacteria were facultatively anaerobic, Gram-negative rods and motile by means of a single polar flagellum. Strain WP2Twas psychrophilic, growing optimally at about 10–15 °C, whereas strain WP3Twas psychrotolerant, growing optimally at 15–20 °C. The two strains grew in the pressure range 0.1–50 MPa, with optimal growth at 20 MPa. Strain WP3Twas able to use nitrate, fumarate, trimethylamineN-oxide (TMAO), DMSO and insoluble Fe(III) as terminal electron acceptors during anaerobic growth, whereas strain WP2Twas able to use only nitrate, TMAO and DMSO. The 16S rRNA gene sequences of strains WP2Tand WP3Twere 97 % identical, and showed highest similarity (97 %) to those ofShewanella fidelisKMM 3589 andShewanella benthicaATCC 43992T, respectively. ThegyrBgene sequences of strains WP2Tand WP3Twere also determined, and showed highest similarity to those ofShewanella violaceaJCM 10179T(90 %) andShewanella sairaeSM2-1T(87 %), respectively. Contrary to the 16S rRNA gene sequence results, the phylogeny based ongyrBgene sequence analysis placed strain WP2T,S. violaceaandS. benthicain one group, while strain WP3Tgrouped withS. fidelisandS. sairae. DNA–DNA hybridization experiments supported the placement of strain WP2TwithS. violaceaandS. benthica. Phylogenetic evidence, together with DNA–DNA relatedness and phenotypic characteristics, indicated that the two new strains represented two novel deep-seaShewanellaspecies. The namesShewanella psychrophilasp. nov. (type strain WP2T=JCM 13876T=CGMCC 1.6159T) andShewanella piezotolerans(type strain WP3T=JCM 13877T=CGMCC 1.6160T) are proposed.
Petrotoga halophila sp. nov., a thermophilic, moderately halophilic, fermentative bacterium isolated from an offshore oil well in Congo
Authors: Miranda-Tello Elizabeth , Fardeau Marie-Laure , Joulian Catherine , Magot Michel , Thomas Pierre , Tholozan Jean-Luc , Ollivier Bernard
Published: January 2007

A novel thermophilic, moderately halophilic, rod-shaped bacterium, strain MET-BT, with a sheath-like outer structure (toga) was isolated from an offshore oil-producing well in Congo, West Africa. Strain MET-BTwas a Gram-negative bacterium with the ability to reduce elemental sulfur, but not sulfate, thiosulfate or sulfite into sulfide. The optimum growth conditions were 60 °C, pH 6.7–7.2 and 4–6 % NaCl. The DNA G+C content was 34.6 mol%. Strain MET-BTwas phylogenetically related to members of the genusPetrotoga;Petrotoga miotherma,Petrotoga oleariaandPetrotoga mexicanawere the closest relatives, with type strains exhibiting more than 99 % identity in an analysis of small-subunit rRNA gene sequences. The values for DNA–DNA relatedness between the type strains of these three species and strain MET-BTwere less than 42 %. As MET-BTwas found to be genetically and physiologically different from other species of the genusPetrotoga, this strain is proposed as representing a novel species, for which the namePetrotoga halophilasp. nov. is proposed. The type strain is MET-BT(=DSM 16923T=CCUG 50214T).
Pseudoalteromonas marina sp. nov., a marine bacterium isolated from tidal flats of the Yellow Sea, and reclassification of Pseudoalteromonas sagamiensis as Algicola sagamiensis comb. nov.
Authors: Nam Young-Do , Chang Ho-Won , Park Ja Ryeong , Kwon Hyuk-Yong , Quan Zhe-Xue , Park Yong-Ha , Lee Jung-Sook , Yoon Jung-Hoon , Bae Jin-Woo
Published: January 2007

Two Gram-negative, motile and strictly aerobic marine bacteria were isolated from a tidal flat sediment sample obtained from Dae-Chun, Chung-Nam, Korea. They were preliminarily identified asPseudoalteromonas-like bacteria, based on 16S rRNA gene sequence analysis showing nearly identical sequences (>99.7 % sequence similarity) and the highest similarity (98.4 %) to the speciesPseudoalteromonas undina. Some phenotypic features of the newly isolated strains were similar to those of members of the genusPseudoalteromonas, but several physiological and chemo-taxonomical properties readily distinguished the new isolates from previously described species. DNA–DNA hybridization with type strains of phylogenetically closely related species demonstrated that the isolates represent a novelPseudoalteromonasspecies, for which the namePseudoalteromonas marinasp. nov. is proposed, with the type strain mano4T(=KCTC 12242T=DSM 17587T). In addition, on the basis of this study and polyphasic data obtained from previous work, it is proposed that the speciesPseudoalteromonas sagamiensisshould be reclassified asAlgicola sagamiensiscomb. nov. and that strain B-10-31T(=DSM 14643T=JCM 11461T) be designated the type strain.
Paenibacillus soli sp. nov., a xylanolytic bacterium isolated from soil
Authors: Park Min-Ju , Kim Ho-Bin , An Dong-Shan , Yang Hee-Chan , Oh Seok-Tae , Chung Hae-Jung , Yang Deok-Chun
Published: January 2007

Two novel polysaccharide-degrading bacteria (strains DCY03T and DCY04) were isolated from a soil sample of a ginseng field in the Republic of Korea and were identified as representing members of the genus Paenibacillus on the basis of phenotypic characteristics and phylogenetic inference based on 16S rRNA gene sequences. Cells of the two isolates were Gram-positive, spore-forming, non-motile, straight rods. Based on DNA–DNA relatedness data, the strains were considered to belong to the same species. The DNA G+C content ranged from 56.6 to 57.0 mol%. The predominant cellular fatty acid was anteiso-C15 : 0 (63.8–62.8 %). Levels of 16S rRNA gene sequence similarity between the two novel isolates and the type strains of recognized Paenibacillus species were 91.4–96.5 %. Strains DCY03T and DCY04 could clearly be distinguished from phylogenetically closely related Paenibacillus species on the basis of DNA–DNA relatedness data and phenotypic characteristics. Therefore, on the basis of these data, the two isolates are considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus soli sp. nov. is proposed. The type strain is DCY03T (=KCTC 13010T=LMG 23604T).
Simplicispira limi sp. nov., isolated from activated sludge
Authors: Lu Shipeng , Ryu Seung Hyun , Chung Bok Sil , Chung Young Ryun , Park Woojun , Jeon Che Ok
Published: January 2007

A Gram-negative, motile, rod-shaped bacterium, designated strain EMB325T, was isolated from activated sludge that performed enhanced biological phosphorus removal in a sequencing batch reactor. The predominant fatty acids of strain EMB325T were summed feature 3 (C16 : 1
ω7c and/or iso-C15 : 0 2-OH), C16 : 0, C18 : 1
ω7c and C18 : 1
ω7c 11-methyl. The strain contained phosphatidylethanolamine and diphosphatidylglycerol as polar lipids. The G+C content of the genomic DNA was 63.3 mol%. The major quinone was Q-8. Phylogenetic analysis of 16S rRNA gene sequences showed that strain EMB325T formed a phyletic lineage with members of the genus Simplicispira and was most closely related to Simplicispira psychrophila LMG 5408T and Simplicispira metamorpha DSM 1837T with similarities of 98.1 and 97.9 %, respectively. Levels of DNA–DNA relatedness between strain EMB325T and S. psychrophila LMG 5408T and S. metamorpha DSM 1837T were 28 and 23 %, respectively. On the basis of chemotaxonomic data and molecular characteristics, strain EMB325T is considered to represent a novel species within the genus Simplicispira, for which the name Simplicispira limi sp. nov. is proposed. The type strain is EMB325T (=KCTC 12608T=DSM 17964T).
Chryseobacterium caeni sp. nov., isolated from bioreactor sludge
Authors: Quan Zhe-Xue , Kim Kwang Kyu , Kim Myung-Kyum , Jin Long , Lee Sung-Taik
Published: January 2007

A Gram-negative, non-spore-forming, yellow-pigmented bacterium, strain N4T, was isolated from a nickel-complexed cyanide-degrading bioreactor and subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain N4T is affiliated to the genus Chryseobacterium of the family Flavobacteriaceae. The levels of 16S rRNA gene sequence similarity between strain N4T and the type strains of all known Chryseobacterium species were 93.2–95.8 %, suggesting that strain N4T represents a novel species within the genus Chryseobacterium. The strain contained iso-C15 : 0 and summed feature 4 as the major fatty acids and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 38.2 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain N4T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium caeni sp. nov. is proposed. The type strain is N4T (=KCTC 12506T=CCBAU 10201T=DSM 17710T).
Nocardioides insulae sp. nov., isolated from soil
Authors: Yoon Jung-Hoon , Kang So-Jung , Lee Choong-Hwan , Oh Tae-Kwang
Published: January 2007

A Gram-positive, rod-shaped or coccoid bacterial strain, DS-51T, was isolated from a soil in Dokdo, Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain DS-51T grew optimally at pH 8.0 and 30 °C without NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DS-51T forms a distinct line of descent within the radiation enclosed by the genus Nocardioides. The chemotaxonomic properties of strain DS-51T were consistent with those of the genus Nocardioides: the cell-wall peptidoglycan type was based on ll-2,6-diaminopimelic acid, MK-8(H4) was the predominant menaquinone and iso-C16 : 0 was the major fatty acid. The DNA G+C content was 71.1 mol%. The 16S rRNA gene sequence of strain DS-51T had similarity levels of 92.5–95.1 % with the sequences of the type strains of Nocardioides species. Strain DS-51T could be distinguished from other Nocardioides species by differences in some phenotypic characteristics. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain DS-51T represents a novel species of the genus Nocardioides, for which the name Nocardioides insulae sp. nov. is proposed. The type strain is DS-51T (=KCTC 19180T=DSM 17944T).
Metschnikowia cerradonensis sp. nov., a yeast species isolated from ephemeral flowers and their nitidulid beetles in Brazil
Authors: Rosa Carlos A. , Lachance Marc-André , Teixeira Lia C. R. S. , Pimenta Raphael S. , Morais Paula B.
Published: January 2007

A novel yeast species, Metschnikowia cerradonensis sp. nov., is described from 12 strains isolated from flowers of Ipomoea carnea and from beetles of the genus Conotelus in the Cerrado ecosystem in the region of Jalapão, Tocantins State, Brazil. Analysis of the sequences of the rRNA gene cluster suggested that M. cerradonensis is closely related to Metschnikowia santaceciliae, Metschnikowia continentalis and an undescribed species represented by strain UWOPS 00-154.1. These species mate together but ascospores are very rarely formed, showing that they represent distinct biological species. M. cerradonensis is apparently endemic to the Cerrado ecosystem of the Jalapão area. The type strain of M. cerradonensis is UFMG 03-T67.1T (h+) (=CBS 10409T=NRRL Y-48067T) and the designated allotype is UFMG 03-T68.1 (h−) (=CBS 10410=NRRL Y-48068).
Desulfovirgula thermocuniculi gen. nov., sp. nov., a thermophilic sulfate-reducer isolated from a geothermal underground mine in Japan
Authors: Kaksonen Anna H. , Spring Stefan , Schumann Peter , Kroppenstedt Reiner M. , Puhakka Jaakko A.
Published: January 2007

A thermophilic, Gram-positive, endospore-forming, sulfate-reducing bacterial strain, designated RL80JIVT, was isolated from a geothermally active underground mine in Japan. Cells were rod-shaped and motile. The temperature and pH ranges for growth were 61–80 °C (optimum at 69–72 °C) and pH 6.4–7.9 (optimum at pH 6.8–7.3), and the strain tolerated up to 0.5 % NaCl. Strain RL80JIVTutilized sulfate, sulfite, thiosulfate and elemental sulfur as electron acceptors. Electron donors utilized were H2in the presence of CO2, and carboxylic acids. Fermentative growth occurred on lactate and pyruvate. The cell wall containedmeso-diaminopimelic acid and the major respiratory isoprenoid quinone was menaquinone MK-7. Major whole-cell fatty acids were iso-C15 : 0, iso-C17 : 0and C16 : 0. Strain RL80JIVTwas found to be affiliated with the thiosulfate-reducerThermanaeromonas toyohensisDSM 14490T(90.9 % 16S rRNA gene sequence similarity) and with the sulfate-reducerDesulfotomaculum thermocisternumDSM 10259T(90.0 % similarity). Strain RL80JIVTis therefore considered to represent a novel species of a new genus, for which the nameDesulfovirgula thermocuniculigen. nov., sp. nov. is proposed. The type strain ofDesulfovirgula thermocuniculiis RL80JIVT(=DSM 16036T=JCM 13928T).
Adoptive transfer of syngeneic T cells in HIV‐1 discordant twins indicates rapid regulation of T‐cell homeostasis
Authors: Hoffmann Christian , Stellbrink Hans‐Juergen , Dielschneider Thomas , Degen Olaf , Stoehr Albrecht , Knechten Heribert , Wolf Eva , Van Lunzen Jan
Published: January 2007

The safety and efficacy of adoptive T‐cell transfer (ATT) was tested in the context of viral suppression in syngeneic twins discordant for human immunodeficiency virus type 1 (HIV‐1) infection. Human leucocyte antigen‐matched T cells of seven HIV‐negative twins were obtained by lymphapheresis and immediately transfused into the HIV‐infected sibling. Four twins received 12 ATTs each, with a mean of 2·10 ± 0·97 × 109CD4+T cells and 1·74 ± 0·81 × 109CD8+T cells. Additional transfers were performed in three more twin pairs to study the short‐term kinetics of transfused syngeneic T cells. Mean CD4+T‐cell counts increased significantly, by 0·133 ± 0·136 × 109 cells/l at 1 h and 0·144 ± 0·12 × 109 cells/l at 3 h post‐transfusion (P < 0·0001). Short‐term kinetic studies suggested a rapid clearance of transferred T cells from the peripheral blood within minutes due to a distribution to marginal pools. After a mean follow up of 39 months, however, a sustained increase of the mean CD4+T‐cell count was observed (from 0·232 × 109to 0·523 × 109 cells/l) without changes of plasma viraemia. We conclude that ATT combined with highly active antiretroviral therapy is safe and leads to a considerable increase in CD4+T‐cell numbers. The clearance kinetics of the transfused cells from peripheral blood indicates a very rapid regulation of T‐cell homeostasis in HIV infection.
Bone mass density in adults with sickle cell disease
Authors: Sarrai Mona , Duroseau Herold , D‘Augustine Jean , Moktan Sabita , Bellevue Rita
Published: January 2007

Sickle cell disease (SCD) leads to many complications including osteoporosis and osteopenia. We studied the prevalence and predisposing factors of low bone mass density (BMD) in adults with SCD. In this retrospective study, dual X‐ray absorptiometry bone scans were used to determine BMD in the lumbar spine, femoral neck and ultra distal radius of 103 patients (73 females, 30 males, aged 15–80 years). Chart reviews and a patient questionnaire were used to collect patient characteristics, disease course and severity, and low BMD risk factors. The 79·6% of patients (mean age 36·5 ± 12·5 years) had an abnormal BMD, with a predilection for the lumbar spine (P = 0·001). Analysis by 3 (low BMD versus very low BMD versus normal) or by 2 groups (abnormal versus normal) showed that abnormal BMD was associated with lower body mass index (BMI) (P = 0·003), lower Hb level (P = 0·001) and higher ferritin (P = 0·003). Low BMD patients were more likely to be SS, SC or Sβ0thal than Sβ+thal (P = 0·022). Abnormal BMD was not related to age, sex, menarche, SCD complications, number of crises, iron overload, treatment with hydroxycarbamide or desferal, renal disease, smoking or alcohol. Patients treated with hydroxycarbamide for at least 6 months were more likely to have an abnormal BMD. In this SCD population, abnormal BMD seemed to be independent of sex, age and menopause, whereas BMI, ferritin level, Hb type and level appeared to play a major role.
Charge differences between in vivo deposits in immunoglobulin light chain amyloidosis and non‐amyloid light chain deposition disease*
Authors: Kaplan Batia , Livneh Avi , Gallo Gloria
Published: January 2007

Immunoglobulin light chain amyloidosis (AL) and non‐amyloid light chain deposition disease (NALCDD) are different forms of protein aggregation disorders that may occur in plasma cell dyscrasias with dysproteinemia. In systemic AL, the deposits are fibrillar and patchy in distribution, within and amongst different organs, whereas in NALCDD, the deposits are granular and diffusely distributed in systemic basement membranes, suggesting different mechanisms of aggregation and deposition. Previous evidence, that charge differences between the light chains in AL and NALCDD might account for their different phenotypes, prompted the present study, which compared the isoelectric points (pIs) of AL and NALCDD protein deposits extracted from human tissues. The pI profiles (5·2–8·8) of polypeptides in AL deposits were heterogenous in four cases, with a spread of both anionic and cationic isoforms; in contrast, in three of NALCDD the pI profiles (8·2–8·8) were homogeneous and restricted in the cationic range. These in vivo findings in human disease, together with other reported in vitro and in vivo experimental data, suggest that the fibrillar deposits in AL may form by electrostatic interaction between oppositely charged polypeptides, whereas the granular deposits in NALCDD form by the binding of cationic polypeptides to anionic proteoglycans sites in basement membranes.
Putting context in the statistics: paediatricians’ experiences discussing obesity during office visits
Authors: Barlow S. E. , Richert M. , Baker E. A.
Published: January 2007

Introduction  Surveys poorly capture how paediatric providers interact with individual patients and families to encourage behaviour change for obesity treatment. Paediatricians’ descriptions of their specific experiences may suggest new ways to approach office‐based obesity care.

Methods  Face‐to‐face interviews with eight paediatricians from diverse backgrounds and practice settings in the Saint Louis area. They described their experiences identifying and treating obesity, the perceived response and suggestions for improved office‐based treatment. Transcriptions of audiotaped interviews were analysed using qualitative techniques.

Results  Paediatricians believed they identify most overweight children but without the use of body mass index (BMI). They recognized excess weight using weight and height charts, which also helped them inform families of the condition. Consistent with available recommendations, the paediatricians emphasized health problems of obesity, advised simple behaviour changes for the entire household and adapted messages to individual families. They sometimes took extra time to discuss obesity. Despite their efforts, they observed almost no success. In addition to poor home environments in many families, they described low family commitment. In their experience, the rare, successful patients came to office visits already motivated. They suggested some office‐based improvements, such as better handouts although they stressed the need for improved school and community environments.

Conclusion  Despite following available obesity treatment recommendations, the paediatricians observed little success. These findings suggest that promoting paediatrician compliance with recommendations will not improve outcome. Instead, improving patient motivation prior to visits and new handouts designed with parent input may be more effective. BMI use will likely increase only when paediatricians are persuaded of its utility.