bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental basis for telencephalon expansion in waterfowl: enlargement prior to neurogenesis
Authors: Charvet Christine J. , Striedter Georg F.
Published: July 2009

Some altricial and some precocial species of birds have evolved enlarged telencephalons compared with other birds. Previous work has shown that finches and parakeets, two species that hatch in an immature (i.e. altricial) state, enlarged their telencephalon by delaying telencephalic neurogenesis. To determine whether species that hatch in a relatively mature (i.e. precocial) state also enlarged their telencephalon by delaying telencephalic neurogenesis, we examined brain development in geese, ducks, turkeys and chickens, which are all precocial. Whereas the telencephalon occupies less than 55 per cent of the brain in chickens and turkeys, it occupies more than 65 per cent in ducks and geese. To determine how these species differences in adult brain region proportions arise during development, we examined brain maturation (i.e. neurogenesis timing) and estimated telencephalon, tectum and medulla volumes from serial Nissl-stained sections in the four species. We found that incubation time predicts the timing of neurogenesis in all major brain regions and that the telencephalon is proportionally larger in ducks and geese before telencephalic neurogenesis begins. These findings demonstrate that the expansion of the telencephalon in ducks and geese is achieved by altering development prior to neurogenesis onset. Thus, precocial and altricial species evolved different developmental strategies to expand their telencephalon.
A probabilistic approach for SNP discovery in high-throughput human resequencing data
Authors: Hoberman Rose , Dias Joana , Ge Bing , Harmsen Eef , Mayhew Michael , Verlaan Dominique J. , Kwan Tony , Dewar Ken , Blanchette Mathieu , Pastinen Tomi
Published: July 2009

New high-throughput sequencing technologies are generating large amounts of sequence data, allowing the development of targeted large-scale resequencing studies. For these studies, accurate identification of polymorphic sites is crucial. Heterozygous sites are particularly difficult to identify, especially in regions of low coverage. We present a new strategy for identifying heterozygous sites in a single individual by using a machine learning approach that generates a heterozygosity score for each chromosomal position. Our approach also facilitates the identification of regions with unequal representation of two alleles and other poorly sequenced regions. The availability of confidence scores allows for a principled combination of sequencing results from multiple samples. We evaluate our method on a gold standard data genotype set from HapMap. We are able to classify sites in this data set as heterozygous or homozygous with 98.5% accuracy. In de novo data our probabilistic heterozygote detection (“ProbHD”) is able to identify 93% of heterozygous sites at a <5% false call rate (FCR) as estimated based on independent genotyping results. In direct comparison of ProbHD with high-coverage 1000 Genomes sequencing available for a subset of our data, we observe >99.9% overall agreement for genotype calls and close to 90% agreement for heterozygote calls. Overall, our data indicate that high-throughput resequencing of human genomic regions requires careful attention to systematic biases in sample preparation as well as sequence contexts, and that their impact can be alleviated by machine learning-based sequence analyses allowing more accurate extraction of true DNA variants.
Gas Pressure Sintering of Silicon Nitride Powder Coated with Al2O3 and TiO2
Authors: Biswas Sampad K. , Riley Frank L.
Published: July 2009

Gas pressure sintering kinetics of silicon nitride powder coated with 10 wt% (9:1) Al2O3 and TiO2 have been studied at 1850°C with a pressure schedule of 0.3 MPa in the first stage and 1 MPa in the second stage. The rates have been analyzed with a liquid‐phase sintering model. Diffusion‐controlled intermediate‐stage kinetics have been observed. The role of second‐step pressurization with nitrogen and argon has been determined by monitoring the kinetics. Pressurization at an earlier stage (∼90% relative density) reduces the densification rate but produces a denser material at the final stage. Although final density is greater, a porous surface layer forms on samples sintered with argon pressurization at the second stage. No such porous layer is formed in the case of pressurization with nitrogen. The mechanism of the intermediate‐stage kinetics has been discussed with respect to the nature of the product analyzed by XRD after sintering.
Single‐Calcination Synthesis of Pyrochlore‐Free 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 and Pb(Mg1/3Nb2/3)O3 Ceramics Using a Coating Method
Authors: Gu Huiming , Shih Wan Y. , Shih Wei‐Heng
Published: July 2009

A coating approach for synthesizing 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 (0.9PMN–0.1PT) and PMN using a single calcination step was demonstrated. The pyrochlore phase was prevented by coating Mg(OH)2 on Nb2O5 particles. Coating of Mg(OH)2 on Nb2O5 was done by precipitating Mg(OH)2 in an aqueous Nb2O5 suspension at pH 10. The coating was confirmed using optical micrographs and zeta‐potential measurements. A single calcination treatment of the Mg(OH)2‐coated Nb2O5 particles mixed with appropriate amounts of PbO and PbTiO3 powders at 900°C for 2 h produced pyrochlore‐free perovskite 0.9PMN–0.1PT and PMN powders. The elimination of the pyrochlore phase was attributed to the separation of PbO and Nb2O5 by the Mg(OH)2 coating. The Mg(OH)2 coating on the Nb2O5 improved the mixing of Mg(OH)2 and Nb2O5 and decreased the temperature for complete columbite conversion to ∼850°C. The pyrochlore‐free perovskite 0.9PMN–0.1PT powders were sintered to 97% density at 1150°C. The sintered 0.9PMN–0.1PT ceramics exhibited a dielectric constant maximum of ∼24 660 at 45°C at a frequency of 1 kHz.
Ceramization of Reflux‐Treated Polymethylsilane Precursors to Silicon Carbide
Authors: Narisawa Masaki , Iseki Takashi , Katase Yoshiro , Okamura Kiyohito , Oka Kunio , Dohmaru Takaaki
Published: July 2009

The pyrolysis of polymethylsilane (PMS) in an argon gas environment with a flow rate of 1 L/min was investigated as a standard pyrolytic process, and the investigation showed SiSi network formation at 573 K. Subsequently, various condensed PMS resins were prepared by adjusting pre‐heat‐treatment or reflux conditions in the temperature range of 423–723 K. The effect of pre‐heat treatment or refluxing on the ceramic yield at 1273 K was quantitatively evaluated. Structural evolution in the PMS resins prepared under various reflux conditions was investigated during pyrolysis up to 1873 K. The X‐ray diffraction patterns of the pyrolysis products revealed crystallite growth of β‐SiC and silicon at 1273–1473 K. 29Si solid‐state nuclear magnetic resonance with the single‐pulse method was also conducted on the pyrolysis products at 1273 K.
Performance of Alumina Membranes from New Nanosynthesis in Ultrafiltration and Nanofiltration
Authors: Krell Andreas , Ma Hongwei
Published: July 2009

Starting from simple inorganic or organic raw materials in aqueous or alcoholic solvents, a synthesis process has been developed for (i) the preparation of sol–gel‐derived alumina (Al2O3) membranes or (ii) the manufacture of membranes by the deposition of precalcined nanocorundum (α‐Al2O3) powders. Because of the equiaxed shape of the synthesized constituent particles, the permeability of the membranes is a factor of 3–5 greater than in previous products. In contrast to the case for known porous transitional Al2O3, the equiaxed shape of the particles in this case is enabled for any of the transitional phases and for the final corundum by a synthesis method that avoids the intermediate crystallization of platelet‐shaped boehmite. By this means, nanoporous Al2O3 components with pore sizes of ∼1 nm or up to 5 nm can be derived preferentially by sol–gel processing, whereas both sol–gel and nanopowder techniques are used to manufacture ultrafiltration α‐Al2O3 membranes with a high chemical and thermal stability and with average pore sizes of 10–60 nm. Compared with the sol–gel approach, powder processing decreases the drying and sintering shrinkage and, thus, the frequency and size of flaws, improving the cutoff characteristics of the membranes. For catalytic applications, the porous ceramic microstructures also can be applied on larger metal substrates.
Reel‐to‐Reel Continuous Chemical Solution Deposition of Epitaxial Gd2O3 Buffer Layers on Biaxially Textured Metal Tapes for the Fabrication of YBa2Cu3O7−δ Coated Conductors
Authors: Aytug Tolga , Paranthaman Mariappan P. , Kang Byeongwon W. , Beach David B. , Sathyamurthy Srivatsan , Specht Eliot D. , Lee Dominic F. , Feenstra Roeland , Goyal Amit , Kroeger Donald M. , Leonard Keith J. , Martin Patrick M. , Christen David K.
Published: July 2009

A nonvacuum reel‐to‐reel dip‐coating system has been used to continuously fabricate epitaxial Gd2O3 buffer layers on mechanically strengthened, biaxially textured Ni–(3 at.% W–1.7 at.% Fe), defined as Ni‐alloy, metal tapes. Because of its significance as a seed layer, optimum processing conditions (postannealing speed and temperature) of Gd2O3 buffer layers have been studied. Highly textured films were obtained under reducing (96% Ar + 4% H2) atmosphere at temperatures between 1100° and 1150°C; postannealing speed did not significantly affect the crystalline quality of the Gd2O3. Scanning electron microscopy revealed a continuous, dense, and crack‐free surface morphology for these dip‐coated buffers. The Gd2O3 layer thickness led to pronounced differences in the growth characteristics of the subsequent YSZ and CeO2 layers deposited by rf‐magnetron sputtering. Epitaxial YBCO films grown by pulsed laser deposition on the short prototype CeO2/YSZ/Gd2O3/Ni–(3 at.% W–1.7 at.% Fe) conductors yielded self‐field critical current densities (Jc) as high as 1.2 × 106 A/cm2 at 77 K. Pure Ni tapes were used to assess the viability of dip‐coated buffers for long length coated conductor fabrication. The YBCO films, grown on 80 cm long and 1 cm wide CeO2/YSZ/Gd2O3 buffered Ni tapes by the industrially scalable ex situ BaF2 precursor process, exhibited end‐to‐end self‐field Jc values of 6.25 × 105 A/cm2 at 77 K. These results demonstrate the reproducible epitaxy of solution‐derived seed layers on pure Ni and Ni‐alloy tapes as well as underscore the viability of solution approaches for the production of long length YBCO‐based coated conductors.
Electroless Copper Coating of Zirconia Utilizing Palladium Catalyst
Authors: Shukla Satyajit , Seal Sudipta
Published: July 2009

Electroless Cu coating of zirconia particles using a Pd0 catalyst is investigated in this paper. Uncoated and Cu‐coated ZrO2 particles are characterized by various analytical techniques to understand the mechanism of electroless Cu coating of ZrO2 particles, which involves reduction of Pd2+ on ZrO2 particle surfaces by Sn2+ to produce pure metallic Pd0 clusters, which provide catalytic sites for Cu deposition. The concept of XPS core‐level binding energy shift due to small cluster size is utilized to predict the size of pure Pd0 clusters. The electroless Cu‐coating process can be utilized in the future to produce Cu‐doped ZrO2 particles required for various potential applications.
Spectroscopic Properties and Local Structure of Eu3+ in Ge–Ga–S–CsBr (or CsCl) Glasses
Authors: Chung Woon Jin , Heo Jong
Published: July 2009

Spectroscopic properties and local structure of Eu3+ in Ge–Ga–S–CsBr (or CsCl) glasses were investigated using fluorescence measurements and several spectroscopic methods. Fluorescence from Eu3+:5D0→7F2 was observed only from glasses with CsBr/Ga ratios greater than unity and disappeared at temperatures above 140 K. Phonon sideband (PSB) spectra revealed that Eu3+ ions are located next to halogen ions, which form part of well‐structured complexes such as EuCl3, tetrahedral [GaS3/2Cl]−, subunits and/or Ga2Cl6. These new bonds showed reduced coupling strength compared with Eu3+–S bonds in Ge–Ga–S glass. Fluorescence line narrowing experiments showed little site‐to‐site variation of Eu3+ ions.
Influence of Interfacial Roughness on Fiber Sliding in Oxide Composites with La‐Monazite Interphases
Authors: Davis Janet B. , Hay Randall S. , Marshall David B. , Morgan Peter E. D. , Sayir Ali
Published: July 2009

Room‐temperature debonding and sliding of fibers coated with La‐monazite is assessed using a composite with a polycrystalline alumina matrix and fibers of several different single crystal (mullite and sapphire) and directionally solidified eutectic (Al2O3/Y3Al5O12 and Al2O3/Y‐ZrO2) compositions. These fibers provide a range of residual stresses and interfacial roughnesses. Sliding occurred over a debond crack at the fiber‐coating interface when the sliding displacement and surface roughness were relatively small. At large sliding displacements with relatively rough interfaces, the monazite coatings were deformed extensively by fracture, dislocations, and occasional twinning, whereas the fibers were undamaged. Dense, fine‐grained areas (10 nm grain size) resembling recrystallized microstructures were also observed in the most heavily deformed regions of the coatings. Frictional heating during sliding is assessed. Potential mechanisms for forming such microstructures at low temperature are discussed, and a parallel is drawn with the known resistance of monazite to radiation damage. The ability of La‐monazite to undergo both debonding and plastic deformation relatively easily at low temperatures may enable its use as a composite interface.
Effectiveness of Monazite Coatings in Oxide/Oxide Composites after Long‐Term Exposure at High Temperature
Authors: Keller Kristin A. , Mah Tai‐Il , Parthasarathy Triplicane A. , Boakye Emmanuel E. , Mogilevsky Pavel , Cinibulk Michael K.
Published: July 2009

The effectiveness of monazite (LaPO4) in providing an oxidation‐resistant weak fiber/matrix interface was evaluated in a fiber roving/thin coating/ceramic‐matrix composite with >20% fiber volume fraction. Nextel™ 610/monazite/alumina composites were fabricated and tensile tested after isothermal exposures of up to 1000 h. Some strength loss was seen after short‐term exposures (1100°–1200°C/5–250 h); however, no further loss was observed after 1000 h at 1200°C. Conversely, control samples containing uncoated fiber displayed >70% strength losses after only 5 h at 1200°C. Fiber pullout was seen in monazite‐containing samples even after 1000 h at 1200°C. Debonding was predominantly in the coating or at either the fiber/coating or coating/matrix interface. Push‐out testing confirmed the weakness of the monazite coating interface.
Effect of Ni and Co Additives on Phase Decomposition in TiB2–WB2 Solid Solutions Formed by Induction Field Activated Combustion Synthesis
Authors: Shibuya Masachika , Yoneda Takanori , Yamamoto Yutaka , Ohyanagi Manshi , Munir Zuhair A.
Published: July 2009

Solid solutions of TiB2–WB2 were densified and annealed simultaneously to cause the decomposition into the phases (Ti,W)B2 and (W,Ti)B2. Ni and Co were added to solid solutions formed by induction field activated combustion synthesis. The presence of these metals as additives markedly enhanced the kinetics of the subsequent decomposition process. With these additives, decomposition to the two phases occurred within minutes (360 s) in contrast to hours when the solutions did not include the additives. The phases resulting from decomposition, (Ti,W)B2 and (W,Ti)B2, were identified by X‐ray to have the hexagonal AlB2 and W2B5 structures, respectively. The precipitated phase, (W,Ti)B2, occurred as elongated grains with aspect ratios of as high as about 10 in samples containing Ni as the additive.
Interactions in the Silicon Carbide–Polyacrylic Acid–Yttrium Ion System
Authors: Hirata Yoshihiro , Tabata Shuhei , Ideue Jun
Published: July 2009

Interactions in the SiC powder–polyacrylic acid (PAA, dispersant)–Y3+ ion (sintering additive) system were investigated in the pH range from 2 to 6. The amount of Y3+ ions adsorbed on SiC particles increased with an increase of pH because of the electrostatic attraction between the negatively charged SiC surface and Y3+ ions. On the other hand, the amount of PAA adsorbed on SiC particles decreased with increasing pH because of the electrostatic repulsion between the negatively charged SiC surface and dissociated PAA. The addition of PAA to the SiC suspension with Y3+ ions increased the amount of Y3+ ions fixed to SiC particles through the strong interaction between Y3+ ions and PAA adsorbed on SiC particles. The above‐described interactions in the SiC–PAA–Y3+ ions system were closely related to the coagulation of SiC particles and the rheology of SiC suspensions. The coagulation of SiC particles through the adsorbed Y3+ ions decreased the specific surface area of SiC powder after calcination in an argon atmosphere. The addition of PAA to the SiC suspensions with Y3+ ions kept the SiC particles separate during calcination, i.e., the PAA addition contributed to enhancement of the driving force of sintering (no decrease of specific surface area) and to control of the amount of Y3+ ions uniformly fixed to the SiC surface.
Fabrication of Silicon Carbide‐Mullite Composite by Melt Infiltration
Authors: Tian Jintao , Shobu Kazuhisa
Published: July 2009

The melt infiltration method was used to fabricate a SiC‐mullite composite at high temperature. Mullite was successfully obtained from a SiO2 and Al2O3 powder mixture by melting above 1830°C in a BN crucible with a lid. When infiltrated into a porous SiC preform, the mullite significantly reacted with SiC to form gaseous SiO and CO, even at the lowest investigated temperature of 1830°C, consuming SiO2 and leaving Al2O3 and silicon phases in the sample. The relevant reactions were studied in detail. A closed system was adopted to suppress the reaction, and a dense composite was successfully obtained.
Kinetic Study of Amorphous Yttria‐Alumina Fibers Using Differential Thermal Analysis
Authors: Reyes Ena A. Aguilar , Drew Robin A. L.
Published: July 2009

Differential thermal analysis (DTA) was used to study the crystallization phenomena in Y2O3‐Al2O3 fibers formed via a melt extraction process. Such fibers are X‐ray amorphous and optically transparent regardless of composition in the as‐extracted state but can be crystallized to produce various equilibrium phases that depend on the original composition of the ceramic rods used in the extraction process. The activation energy values were calculated using Kissinger and Augis‐Bennett equations by measuring the variation of the peak temperature in the differential thermal patterns with heating rate. X‐ray diffractometry analysis was used to determine the phase formation in the fibers crystallized after the DTA scan.
Numerical Simulation of Solid‐State Sintering: I, Sintering of Three Particles
Authors: Tikare Veena , Braginsky Michael , Olevsky Eugene A.
Published: July 2009

A kinetic, Monte Carlo model, capable of simulating microstructural evolution sintering in a two‐dimensional system of three particles, has been presented. The model can simulate several mechanisms simultaneously. It can simulate curvature‐driven grain growth, pore migration and coarsening by surface diffusion, and densification by diffusion of vacancies to grain boundaries and annihilation of these vacancies. Morphologic changes and densification kinetics are used to verify the model.
Push‐Pull Fatigue of Sintered Silicon Nitride Ceramics at Elevated Temperatures
Authors: Hatanaka Kenji , Katsuyama Masashi , Takagi Hideki
Published: July 2009

The fatigue tests under push‐pull completely reversed loading and pulsating loading were performed for silicon nitride ceramics at elevated temperatures. Then the effects of stress wave form, stress rate, and cyclic understressing on fatigue strength, and cyclic straining behavior, were examined. The cycle‐number‐based fatigue life is found to be shorter under trapezoidal stress wave loading than under triangular stress wave loading, and to become shorter with increasing hold time under the trapezoidal stress wave loading. Meanwhile, the equivalent time‐based life curve, which is estimated from the concept of slow crack growth, almost agrees with the static fatigue life curve in the short and intermediate life regions, showing the small cyclic stress effect and the dominant stress‐imposing period effect on cyclic fatigue life. The fatigue strength increased in stepwise stress amplitude increasing test, where stress amplitude is increased stepwise every given number of stress cycles, at 1100° and 1200°C. Occurrence of cyclic strengthening was proved through a gradual decrease in strain amplitude during a pulsating loading test at 1200°C in this material, corresponding to the above cyclic understressing effect on fatigue strength.
Two‐Layer Crystallization of Amorphous YMnO3 Thin Films on Si (100) Substrates
Authors: Yoo Dong Chul , Lee Jeong Yong , Kim Ik Soo , Kim Yong Tae
Published: July 2009

During a rapid thermal annealing process at 850°C in a N2 ambient, an as‐deposited amorphous YMnO3 thin film on Si (100) substrates was crystallized with two distinct layers. High‐resolution transmission electron microscopy showed a top layer of c‐axis‐oriented YMnO3 and a bottom layer of polycrystalline YMnO3 in the 100‐nm‐thick YMnO3 thin film. The abrupt change of the crystalline orientation from the c‐axis‐preferred orientation to the random orientation is caused primarily by high stress induced by the c‐axis‐oriented YMnO3 layer. High‐resolution X‐ray diffraction showed that the c‐axis‐oriented YMnO3/polycrystalline YMnO3 structure effectively relieved the stress.
{111} Twin Formation and Abnormal Grain Growth in Barium Strontium Titanate
Authors: Lee Byoung‐Ki , Jung Yang‐Il , Kang Suk‐Joong L. , Nowotny Janusz
Published: July 2009

Two series of experiments were performed to study the experimental conditions for the formation of {111} twins and related microstructures in barium strontium titanate ((Ba, Sr)TiO3). In the first series, the phase equilibria in the BaTiO3–SrTiO3–TiO2 system were determined. XRD and WDS analysis, done in the BaTiO3‐rich region, of 45(Ba,Sr)TiO3–10TiO2 samples annealed at 1250°C for 200 h in air showed that (Ba,Sr)TiO3 was in equilibrium with Ba6Ti17O40 (B6T17) and Ba4Ti13O30 phases with strontium solubility (Sr/(Ba + Sr)) of ∼0.02 and 0.20, respectively. In the second series the microstructures of samples consisting of a mixture of (Ba,Sr)TiO3 and 2.0 mol% TiO2, were observed after sintering at 1250°C for 100 h in air. {111} twins formed only in the samples with faceted B6T17 second phase particles, similar to the case of BaTiO3. In these samples, abnormal grain growth occurred in the presence of the {111} twins. In contrast, no {111} twins formed and no abnormal grain growth occurred in the samples containing second phase particles other than B6T17. With an increased substitution of strontium for barium, the aspect ratio of abnormal grains containing {111} twin lamellae was reduced. This result was attributed to a reduction in the relative stability of the {111} planes with the strontium substitution.
Precipitation of MgO·nAl2O3 in Mg‐Doped α‐Al2O3 under Electron Irradiation
Authors: Kaneko Kenji , Kato Takeharu , Kitayama Mikio , Tomokiyo Yoshitsugu
Published: July 2009

A number of nanoscale precipitates with random orientations were produced by electron irradiation of polycrystalline Mg‐doped α‐Al2O3. The precipitation behavior and microstructural changes were observed using in situ high‐resolution transmission electron microscopy. A ring pattern corresponding to a polycrystalline fcc structure was obtained from the region of these precipitates by selected‐area diffraction, and they were identified as nonstoichiometric MgO·nAl2O3. It is believed that Al2O3 with MgO(ss) and/or MgO at the grain boundaries is effectively stabilized by the electron irradiation process, forming the fundamental structure of MgO·nAl2O3. The average size of the precipitates is about 10 nm.
Energy‐Filtering Transmission Electron Microscopy (EF‐TEM) Study of a Modulated Structure in Metakaolinite, Represented by a 14 Å Modulation
Authors: Lee Sujeong , Kim Youn Joong , Moon Hi‐Soo
Published: July 2009

For the first time, a periodicity of 14 Å is recognized as a typical modulation period in metakaolinite. Energy‐filtered electron diffraction data confirm that dehydroxylation does not occur abruptly in kaolinite. The degree of ordering becomes much lower during the progression of dehydroxylation in metakaolinite than in kaolinite. However, different types of modulations, with periods in the range from ∼1.4d001 (9.47 Å) to 2.9d001 (19.89 Å), form along the c*‐axis in metakaolinite. Modules (14.2 Å= 2.1d001) that have a length that is approximately twice as long as the metakaolinite layer (6.86 Å) are the most common. Presumably, the remnant oxygens and vacant anion sites rearrange to acquire stability in the layer structure, which builds modulations along the c*‐axis in the metakaolinite.
Toughening of Glass by a Piezoelectric Secondary Phase
Authors: Boccaccini Aldo R. , Pearce David H.
Published: July 2009

A toughening concept for glass, based on exploiting the ferroelastic effect of piezoelectric particles embedded in a glass matrix, is described. It is hypothesized that the domains within a piezoelectric phase will align themselves in the direction of the stress field around an advancing crack, thus absorbing energy and contributing to toughening. A powder technology route was optimized to fabricate lead‐containing glass‐matrix composites with up to 30 wt% of a lead zirconate titanate (PZT) particulate phase. An increase in fracture toughness of >50% was achieved via the addition of 30 wt% of PZT particles. Although other toughening mechanisms could be excluded in the present composites, the actual contribution of piezoelectric toughening remains under investigation.
Role of α‐Fe2O3 Morphology on the Color of Red Pigment for Porcelain
Authors: Katsuki Hiroaki , Komarneni Sridhar
Published: July 2009

To produce a new red pigment for Japanese porcelains, some hematite (α‐Fe2O3) powders produced by different methods were investigated by mixing them with lead‐free frit powders and firing them on white porcelain plates at 800°C. Commercial hematite powders and uniform α‐Fe2O3 powders 155 and 53 nm in diameter which were prepared using conventional‐ and microwave‐hydrothermal reactions, respectively, were used as sources of red pigments. The morphology and dispersion of the above α‐Fe2O3 powders were found to have a significant effect on the tone of red color for porcelain pigment.
Measurement of Small Concentrations of Manganese in Lime (CaO) Using Electron Spin Resonance
Authors: de Biasi Ronaldo S. , Grillo Maria L. N.
Published: July 2009

Electron spin resonance (ESR) line widths of Mn2+ in lime were measured in samples doped with small concentrations (up to 0.4 mol%) of Mn. The line width was found to change in a predictable way with Mn concentration, according to the theoretical equation ΔHpp= 0.23 + 240f(1 −f)42, where ΔHpp is the line width in milliteslas and f is the Mn concentration in mole percent. The experimental results show that the technique can be used to measure, rapidly and nondestructively, small concentrations of Mn in commercial CaO.
Gastric mucosal interleukin‐17 and ‐18 mRNA expression in Helicobacter pylori‐induced Mongolian gerbils
Authors: Sugimoto Mitsushige , Ohno Tomoyuki , Graham David Y. , Yamaoka Yoshio
Published: July 2009

Helicobacter pylori infection causes characteristic mucosal infiltration of inflammatory cells, resulting in the development of peptic ulcers and gastric cancer in approximately 10% of cases. Different clinical expressions of the infection may reflect different patterns of cytokine expression. Interleukin (IL)‐1ß, tumor necrosis factor (TNF)‐α, IL‐17, and IL‐18 have been reported to be involved in H. pylori‐induced gastric mucosal inflammation, but the details and relation to different patterns of inflammation remain unclear. Moreover, the proinflammatory virulence factor outer inflammatory protein (OipA) was reported to be associated with gastric mucosal inflammatory cytokine levels. To clarify these findings, Mongolian gerbils were infected for up to 12 months with wild‐type H. pylori 7.13 or with isogenic oipA mutants for 3 months, and mucosal cytokines (IL‐1ß, IL‐17, IL‐18, and TNF‐α) mRNA levels were then assessed using real‐time RT‐PCR. Antral mucosal IL‐1β and IL‐18 mRNA levels peaked 1 month after infection, whereas the peak of TNF‐α mRNA was at 6–12 months; IL‐17 levels peaked at 12 months. The inflammatory cell infiltration and mRNA levels of all cytokines studied were significantly lower in oipA mutants than in wild‐type‐infected gerbils. Mucosal IL‐1ß, IL‐17, and TNF‐α expression, but not that of IL‐18, were significantly associated with the grade of inflammatory cell infiltration. The pattern of increased inflammatory cytokines differed relative to the phase of the infection and pattern of inflammation. OipA appears to play a role in IL‐1ß, IL‐17, and TNF‐α expression and the resulting inflammation. (Cancer Sci 2009)
Phase 2 study of weekly bortezomib in mantle cell and follicular lymphoma
Authors: Gerecitano John , Portlock Carol , Moskowitz Craig , Hamlin Paul , Straus David , Zelenetz Andrew D. , Zhang Zhigang , Dumitrescu Otilia , Sarasohn Debra , Lin Dorothy , Pappanicholaou Jennifer , Cortelli Barbara M. , Neylon Ellen , Hamelers Rachel , Wright John , O’Connor Owen A.
Published: July 2009

Twice‐weekly bortezomib has proven activity in mantle cell (MCL) and indolent lymphomas. This study explored a weekly schedule of bortezomib in follicular lymphoma (FL) and MCL. Although weekly bortezomib was better tolerated, the overall response rate (ORR) was inferior (18% vs. 50%, P = 0·02) with no complete remissions (CR) (compared with 18% CR for the twice‐weekly schedule). Progression‐free survival (PFS) was not different. The weekly schedule of bortezomib was less toxic, but yielded fewer and lower quality responses than twice‐weekly bortezomib. Given the similar PFS, the weekly schedule may still be appropriate for some patients.
RQ‐PCR based WT1 expression in comparison to BCR‐ABL quantification can predict Philadelphia negative clonal evolution in patients with imatinib‐treated chronic myeloid leukaemia
Authors: Schnittger Susanne , Bacher Ulrike , Kern Wolfgang , Tschulik Claudia , Weiss Tamara , Haferlach Claudia , Haferlach Torsten
Published: July 2009

A retrospective comparison of WT1 and BCR‐ABL1 expression was performed in 40 imatinib‐treated chronic myeloid leukaemia patients. The overall correlation of WT1 and BCR‐ABL1 was low. In two patients WT1 expression was increasing despite very low BCR‐ABL1 levels. As both revealed Ph‐negative aberrant clones, a second independent cohort of 20 cases, all with Ph‐negative clonal evolution, was analysed. High WT1 expression (5·0–177·0%) was detected in a case with +11 and in four of eight cases with +8, but not in cases with del(20q) or −Y. Thus, increasing WT1 levels in molecular responders may indicate Ph‐negative clonal cytogenetic evolution during imatinib treatment.
The non‐specific lipid transfer protein, Ara h 9, is an important allergen in peanut
Authors: Lauer I. , Dueringer N. , Pokoj S. , Rehm S. , Zoccatelli G. , Reese G. , Miguel‐Moncin M. S. , Cistero‐Bahima A. , Enrique E. , Lidholm J. , Vieths S. , Scheurer S.
Published: July 2009

Background
Plant food allergy in the Mediterranean area is mainly caused by non‐specific lipid transfer proteins (nsLTP). The aim of this study was to characterize peanut nsLTP in comparison with peach nsLTP, Pru p 3, and assess its importance in peanut allergy.

Methods
Peanut‐allergic patients from Spain (n=32) were included on the basis of a positive case history and either a positive skin prick test or specific IgE to peanut. For comparison, sera of 41 peanut‐allergic subjects from outside the Mediterranean area were used. Natural Ara h 9 and two isoforms of recombinant Ara h 9, expressed in Pichia pastoris, were purified using a two‐step chromatographic procedure. Allergen characterization was carried out by N‐terminal sequencing, circular dichroism (CD) spectroscopy, immunoblotting, IgE inhibition tests and basophil histamine release assays.

Results
Compared with natural peanut nsLTP, the recombinant proteins could be purified in high amounts from yeast supernatant (45 mg/L). The identity of the proteins was verified by N‐terminal amino acid sequencing and with rabbit nsLTP‐specific antibodies. CD spectroscopy revealed similar secondary structures for all preparations and Pru p 3. The Ara h 9 isoforms showed 62–68% amino acid sequence identity with Pru p 3. IgE antibody reactivity to rAra h 9 was present in 29/32 Spanish and 6/41 non‐Mediterranean subjects. Recombinant Ara h 9 showed strong cross‐reactivity to nPru p 3 and similar IgE‐binding capacity as nAra h 9. The two Ara h 9 isoforms displayed similar IgE reactivity. In peanut‐allergic patients with concomitant peach allergy, Ara h 9 showed a weaker allergenic potency than Pru p 3 in histamine release assays.

Conclusions
Ara h 9 is a major allergen in peanut‐allergic patients from the Mediterranean area. Ara h 9 is capable of inducing histamine release from basophils, but to a lesser extent than Pru p 3.
CD4+CD25+ T cell depletion impairs tolerance induction in a murine model of asthma
Authors: Boudousquié C. , Pellaton C. , Barbier N. , Spertini F.
Published: July 2009

Background
Regulatory T cells (Tregs) are key players in controlling the development of airway inflammation. However, their role in the mechanisms leading to tolerance in established allergic asthma is unclear.

Objective
To examine the role of Tregs in tolerance induction in a murine model of asthma.

Methods
Ovalbumin (OVA) sensitized asthmatic mice were depleted or not of CD25+ T cells by anti‐CD25 PC61 monoclonal antibody (mAb) before intranasal treatment (INT) with OVA, then challenged with OVA aerosol. To further evaluate the respective regulatory activity of CD4+CD25+ and CD4+CD25− T cells, both T cell subsets were transferred from tolerized or non‐tolerized animals to asthmatic recipients. Bronchoalveolar lavage fluid (BALF), T cell proliferation and cytokine secretion were examined.

Results
Intranasal treatment with OVA led to increased levels of IL‐10, TGF‐β and IL‐17 in lung homogenates, inhibition of eosinophil recruitment into the BALF and antigen specific T cell hyporesponsiveness. CD4+CD25+Foxp3+ T cells were markedly upregulated in lungs and suppressed in vitro and in vivo OVA‐specific T cell responses. Depletion of CD25+ cells before OVA INT severely hampered tolerance induction as indicated by a strong recruitment of eosinophils into BALF and a vigorous T cell response to OVA upon challenge. However, the transfer of CD4+CD25− T cells not only suppressed antigen specific T cell responsiveness but also significantly reduced eosinophil recruitment as opposed to CD4+CD25+ T cells. As compared with control mice, a significantly higher proportion of CD4+CD25− T cells from OVA treated mice expressed mTGF‐β.

Conclusion
Both CD4+CD25+ and CD4+CD25− T cells appear to be essential to tolerance induction. The relationship between both subsets and the mechanisms of their regulatory activity will have to be further analyzed.
High‐risk HPV detection in specimens collected in SurePath preservative fluid: comparison of ambient and refrigerated storage
Authors: Hardie A. , Moore C. , Patnick J. , Cuschieri K. , Graham C. , Beadling C. , Ellis K. , Frew V. , Cubie H. A.
Published: July 2009

Objective:  With moves to introduce human papillomavirus (HPV) triage at sentinel sites in England, it is essential that optimal storage and transport conditions are determined for efficient HPV detection using residual liquid‐based cytology specimens.

Methods:  Two cytology laboratories with comparable workloads sent residual cervical cytology specimens collected in BD Surepath™ Preservative Fluid to the Specialist Virology Centre for HPV testing. Storage and transport of specimens was at ambient (site A) or refrigerated (site R) temperatures. The effect of temperature on the ability to detect high‐risk human papillomavirus (HR‐HPV) using Digene Hybrid Capture® 2 High‐Risk HPV DNA Test (hc2) and Roche AMPLICOR® HPV Test (AMPLICOR) was assessed. All specimens with discordant results were tested using Roche Linear Array HPV Genotyping test.

Results:  A total of 796 residual cytology specimens, with cytology ranging from normal to severe dyskaryosis, were provided (399 from site A and 397 from site R). Ambient storage and transit of cervical specimens in SurePath medium did not appear to affect significantly the suitability of the specimen for HPV testing, as measured by the concordance of the HR‐HPV screening assays for ambient versus refrigerated specimens and by the proportion of specimens which tested invalid.

Conclusion:  Residual cytology specimens in SurePath medium, stored and transported at ambient temperature, appear suitable for HR‐HPV detection by AMPLICOR beyond the manufacturer’s recommended time and potentially up to four weeks.
A compact STED microscope providing 3D nanoscale resolution
Authors: WILDANGER D. , MEDDA R. , KASTRUP L. , HELL S.W.
Published: July 2009

The advent of supercontinuum laser sources has enabled the implementation of compact and tunable stimulated emission depletion fluorescence microscopes for imaging far below the diffraction barrier. Here we report on an enhanced version of this approach displaying an all‐physics based resolution down to (19 ± 3) nm in the focal plane. Alternatively, this single objective lens system can be configured for 3D imaging with resolution down to 45 × 45 × 108 nm in a cell. The obtained results can be further improved by mathematical restoration algorithms. The far‐field optical nanoscale resolution is attained in a variety of biological samples featuring strong variations in the local density of features.
Light‐emitting diode flashlights as effective and inexpensive light sources for fluorescence microscopy
Authors: ROBERTSON J.B. , ZHANG Y. , JOHNSON C.H.
Published: July 2009

Light‐emitting diodes (LEDs) are becoming more commonly used as light sources for fluorescence microscopy. We describe the adaptation of a commercially available light‐emitting diode flashlight for use as a source for fluorescence excitation. This light source is long‐lived, inexpensive and is effective for excitation in the range of 440–600 nm.
Re‐examination of a proposed case of stasipatric speciation: phylogeography of the Australian morabine grasshoppers (Vandiemenella viatica species group)
Authors: KAWAKAMI TAKESHI , BUTLIN ROGER K. , ADAMS MARK , SAINT KATHLEEN M. , PAULL DAVID J. , COOPER STEVEN J. B.
Published: July 2009

Karyotypic differences have been used for delimiting populations or species, although whether these mutations provide strong barriers to gene flow between populations and promote speciation remains contentious. In this study, we assessed whether 11 chromosomal races of Australian morabine grasshoppers (Vandiemenella viatica species group) represent genetically distinct populations by analyses of cytological and allozyme (35 loci) data and DNA sequences of the elongation factor‐1 alpha (EF‐1α), anonymous Mvia11, and mitochondrial cytochrome c oxidase subunit I (COI) loci. While the Vandiemenella chromosomal taxa generally represent genetically distinct units, a substantial portion of the total genetic variation in our samples was not explained by the chromosomal variation. Mantel tests indicated that Vandiemenella populations were spatially structured and have maintained gene flow at a local scale within each of the taxa. The group was subdivided into 13 genetic clusters; four chromosomal taxa comprised single exclusive clusters, while others comprised more than one cluster or clusters shared with other taxa. Boundaries of these cryptic population subdivisions correspond with several biogeographical barriers, such as straits, gulfs, the Murray River, and an ancient mega‐lake, Lake Bungunnia. The viatica species group was previously proposed to have diversified without major geographical separation based on the stasipatric speciation model; however, the present study suggests the involvement of allopatric fragmentation. Given extensive nonmonophyly of chromosomal taxa and incomplete barriers to gene flow among taxa, all Vandiemenella chromosomal taxa and genetically distinct populations within chromosomal taxa, except Vandiemenella pichirichi, should be regarded as populations of one species: Vandiemenella viatica.
Small bowel motility in functional chronic constipation
Authors: Seidl H. , Gundling F. , Pehl C. , Pfeiffer A. , Schepp W. , Schmidt T.
Published: July 2009

Abstract  In functional constipation, three pathophysiological subgroups have been identified: slow‐transit constipation (STC); normal‐transit constipation (NTC) and outlet delay (OD). Extracolonic manifestations, especially disturbed small bowel motility, are well known to occur in STC, but have rarely been studied in NTC and OD. To perform 24‐h‐ambulatory jejunal manometry in a large prospective series of clinical patients with chronic constipation of all subtypes. A total of 61 consecutive patients, referred to our tertiary gastroenterologic centre for chronic constipation (48 female, 13 male; mean age 57 (range 20–87) years), underwent jejunal 24‐h‐ambulatory manometry (standardized meal) after a transit‐time study (radio‐opaque markers), anorectal manometry, defecography and colonoscopy. Computerized and visual analysis by two independent observers was compared with the normal range of manometric variables, defined by data previously obtained in 50 healthy subjects (Gut 1996;38:859). Five patients were excluded from the study because of coexistence of OD and STC. No patient with OD (n = 8), but all patients with STC (n = 32) and 94% of patients with NTC (n = 16) showed small bowel motor abnormalities; both in postprandial response and fasting motility. The abnormal findings ranged from severe disturbances with complete loss of MMC to subtle changes of contraction parameters that could only be assessed by computerized analysis. No significant differences between STC‐ and NTC‐patients were found. Most findings pointed to an underlying enteric neuropathy. Intestinal prolonged‐ambulatory manometry adds valuable information to the pathophysiologic understanding of functional chronic constipation of STC‐ and NTC‐type, however there are no distinct manometric features to differentiate between both.
Quantification of collider‐stratification bias and the birthweight paradox
Authors: Whitcomb Brian W. , Schisterman Enrique F. , Perkins Neil J. , Platt Robert W.
Published: July 2009

The ‘birthweight paradox’ describes the phenomenon whereby birthweight‐specific mortality curves cross when stratified on other exposures, most notably cigarette smoking. The paradox has been noted widely in the literature and numerous explanations and corrections have been suggested. Recently, causal diagrams have been used to illustrate the possibility for collider‐stratification bias in models adjusting for birthweight. When two variables share a common effect, stratification on the variable representing that effect induces a statistical relation between otherwise independent factors. This bias has been proposed to explain the birthweight paradox.

Causal diagrams may illustrate sources of bias, but are limited to describing qualitative effects. In this paper, we provide causal diagrams that illustrate the birthweight paradox and use a simulation study to quantify the collider‐stratification bias under a range of circumstances. Considered circumstances include exposures with and without direct effects on neonatal mortality, as well as with and without indirect effects acting through birthweight on neonatal mortality. The results of these simulations illustrate that when the birthweight–mortality relation is subject to substantial uncontrolled confounding, the bias on estimates of effect adjusted for birthweight may be sufficient to yield opposite causal conclusions, i.e. a factor that poses increased risk appears protective. Effects on stratum‐specific birthweight–mortality curves were considered to illustrate the connection between collider‐stratification bias and the crossing of the curves. The simulations demonstrate the conditions necessary to give rise to empirical evidence of the paradox.
Mastocytosis and insect venom allergy: diagnosis, safety and efficacy of venom immunotherapy
Authors: Niedoszytko M. , De Monchy J. , Van Doormaal J. J. , Jassem E. , Oude Elberink J. N. G.
Published: July 2009

The most important causative factor for anaphylaxis in mastocytosis are insect stings. The purpose of this review is to analyse the available data concerning prevalence, diagnosis, safety and effectiveness of venom immunotherapy (VIT) in mastocytosis patients. If data were unclear, authors were contacted personally for further information. Quality of evidence (A: high, B: moderate, C: low and D: very low) and strength of recommendation (strong 1 and weak 2) concerning VIT in mastocytosis patients are assessed according to the Grading of Recommendations Assessment, Development and Evaluation and are marked in square brackets. Results of VIT were described in 117 patients to date. The mean rate of side‐effects during treatment in studies published so far is 23.9% (7.6% requiring adrenaline) with an overall protection rate of 72%. Based on the review we conclude that (1) mastocytosis patients have a high risk of severe sting reactions in particular to yellow jacket, (2) VIT could be suggested [2] in mastocytosis, (3) probably should be done life long [2], (4) VIT in mastocytosis is accompanied by a higher frequency of side‐effects, so (5) special precautions should be taken into account notably during the built up phase of the therapy [2], (6) VIT is able to reduce systemic reactions, but to a lesser extent compared to the general insect venom allergic population [2], so (7) patients should be warned that the efficacy of VIT might be less than optimal and they should continue carrying two adrenaline auto injectors [2].
Neuromuscular features in Marfan syndrome
Authors: Voermans NC , Timmermans J , Van Alfen N , Pillen S , Op Den Akker J , Lammens M , Zwarts MJ , Van Rooij IALM , Hamel BC , Van Engelen BG
Published: July 2009

Marfan syndrome is a clinically and allelic heterogeneous, heritable connective tissue disorder with infrequently reported neuromuscular features. This study is the first to delineate these symptoms in a non‐selected population. Neuromuscular involvement was evaluated in 10 Marfan patients through a standardized questionnaire, physical examination, nerve conduction study (NCS), needle electromyography (EMG), muscle ultrasound, laboratory investigation, and muscle biopsy. Existing neuroimages were screened for dural ectasia and spinal meningeal cysts. Twenty healthy controls with similar age distribution completed the questionnaire.

The results showed that various neuromuscular symptoms occur more frequently in the patients. Four older patients reported muscle weakness, five patients had a mild‐to‐moderate reduction in vibration sense, and all older patients mentioned mild functional impairments. NCS showed axonal polyneuropathy in four and EMG myopathic and neurogenic changes in all patients. Increased echo intensity and atrophy on muscle ultrasound was found in more than half of the patients. Muscle biopsies obtained in two patients showed myopathic changes in the older, female patient.

In conclusion, the majority of Marfan patients exhibited neuromuscular symptoms characterized as myopathy or polyneuropathy or both, and signs of lumbosacral radiculopathy, with symptoms being most pronounced in the older patients. Although meriting corroboration, these findings indicate a need to further the awareness of neuromuscular involvement in this population.
An important risk factor in idiopathic generalized epilepsies
Authors: Stein RA
Published: July 2009

15q13.3 microdeletions increase risk of idiopathic generalized epilepsy

Helbig et al. (2009)

Nature Genetics 41(2):160–162