bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Core Materials on the Formation of Hollow Alumina Microspheres by Mechanofusion Process
Authors: Kato Takayuki , Ushijima Hitoshi , Katsumata Makoto , Hyodo Takeo , Shimizu Yasuhiro , Egashira Makoto
Published: July 2009

Core/shell structures have been prepared via a mechanofusion system by employing several kinds of spherical polymers as a core material and Al2O3 powder or a mixture of Al2O3 and SiO2 powders as a shell material. The effect of the kind of core polymers on the quality of the resulting hollow alumina microspheres has been discussed on the basis of the thermal decomposition behavior of spherical polymers used as a core material. A large fraction of hollow alumina microspheres reflecting the shape and the particle size distribution of the core polymer could be fabricated after sintering at 1600°3C for 3 h, when highly cross‐linked poly(methyl methacrylate) (PMMA) microspheres with a gel fraction of 99.03% were used as a core polymer, and abrupt firing at temperatures higher than 500°3C was adopted to remove the PMMA microspheres. The addition of 5 mass% SiO2 to the Al2O3 shell layer was found to be useful for maintaining the spherical shell structure during the firing process and for fabricating a large fraction of hollow alumina microspheres after the sintering.
Processing of Lithium Zirconate for Applications in Carbon Dioxide Separation: Structure and Properties of the Powders
Authors: Nair Balagopal N. , Yamaguchi Takeo , Kawamura Hiroto , Nakao Shin‐Ichi , Nakagawa Kazuaki
Published: July 2009

Lithium zirconate, Li2ZrO3, has been reported as a candidate material for high‐temperature CO2 separation. The reaction of Li2ZrO3 with CO2 is extremely fast, and the material can store significant quantities of CO2 at high temperature. The reacted CO2 can be regenerated by thermal cycling. Alternatively, a membrane system might be developed based on the reversible reaction process. For absorption and membrane separation, the particle size, crystal structure, and state of agglomeration of the Li2ZrO3 powders are important. Therefore, we have synthesized Li2ZrO3 using sol‐gel procedures and compared its properties with powders made via a powder‐mixing route and a commercial‐grade powder. The morphologic and structural characteristics of the powders and their CO2 absorption properties are discussed.
Synthesis of BaTiO3 Particles with Tailored Size by Precipitation from Aqueous Solutions
Authors: Testinon Andrea , Buscaglia Maria Teresa , Viviani Massimo , Buscaglia Vincenzo , Nanni Paolo
Published: July 2009

Well‐defined and stoichiometric spherical particles of BaTiO3 of narrow size distribution were produced at 82° and 92°3C by precipitation from chloride solutions in a strong alkaline environment. The size of the particles can be tailored in the range from ≅103 to 70–80 nm by increasing the barium concentration from ≅0.07 to 0.7 mol/L. The particles are composed of tight aggregates resulting from the assembly of several nanocrystals. The size of the nanocrystals decreases from 200–300 to 30–40 nm by increasing reactant concentration. At low barium concentration (≤0.07 mol/L at 82°3C, ≤0.06 mol/L at 92°3C), formation of BaTiO3 is strongly slowed down and nonstoichiometric, Ti‐rich powders are produced. Under these conditions, the particles have the tendency to develop a dendritic‐like morphology.
Thermal Expansion of δ‐Yttrium Disilicate
Authors: Fukuda Koichiro , Matsubara Hiroyuki
Published: July 2009

Crystals of δ‐Y2Si2O7 (space group P121/c1) were examined using high‐temperature powder X‐ray diffractometry to determine their unit‐cell dimensions from 296 to 1473 K. The lattice deformation induced by thermal expansion was investigated using matrix algebra analysis to determine the directions and magnitudes of the principal distortions (Λi, i= 1,2, and 3). The directions of Λ1 and Λ3 were defined by the acute angle Λ1c, which linearly decreased from 5(2)° to —5.5(3)° with increased temperature from 504 to 1473 K. The Λ2‐axis invariably coincided with the crystallographic b‐axis. The magnitudes of Λ1 and Λ2 steadily increased to, respectively, 1.0061(1) and 1.0068(1) during heating to 1473 K, while Λ3 remained almost constant for the entire temperature range. The mean principal distortion, Λm (= (Λ1+Λ2+Λ3)/3), steadily increased to 1.0044(1) with increased temperature to 1473 K. The coefficient of mean linear thermal expansion (α) was derived from the mean principal strain (Λm ‐ 1) as α= (Λm ‐ 1)/ΔT. The temperature dependence was determined to be α= 2.03 times 103+ 1.36(T ‐ 296) (10‐9 K‐1). Provided that the rule‐of‐mixtures holds for the Y2Si2O7/Y2SiO5 composites as protective coating on SiC substrates, the volume fractions of 0.72‐0.77 (70–75 mass%) would be necessary for the Y2Si2O7 component to match the α‐values of both materials.
Effect of a Boron Nitride Interphase That Debonds between the Interphase and the Matrix in SiC/SiC Composites
Authors: Morscher Gregory N. , Yun Hee Mann , DiCarlo James A. , Thomas‐Ogbuji Linus
Published: July 2009

Typically, the debonding and sliding interface enabling fiber pullout for SiC‐fiber‐reinforced SiC‐matrix composites with BN‐based interphases occurs between the fiber and the interphase. Recently, composites have been fabricated where interface debonding and sliding occur between the BN interphase and the matrix. This results in two major improvements in mechanical properties. First, significantly higher failure strains were attained due to the lower interfacial shear strength with no loss in ultimate strength properties of the composites. Second, significantly longer stress‐rupture times at higher stresses were observed in air at 815°3C. In addition, no loss in mechanical properties was observed for composites that did not possess a thin carbon layer between the fiber and the interphase when subjected to burner‐rig exposure. Two primary factors were hypothesized for the occurrence of debonding and sliding between the BN interphase and the SiC matrix: a weaker interface at the BN/matrix interface than the fiber/BN interface and a residual tensile/shear stress‐state at the BN/matrix interface of melt‐infiltrated composites. Also, the occurrence of outside debonding was believed to occur during composite fabrication, i.e., on cooldown after molten silicon infiltration.
Dependence of Grain Growth and Grain‐Boundary Structure on the Ba/Ti Ratio in BaTiO3
Authors: Cho Young Kyu , Kang Suk‐Joong L. , Yoon Duk Yong
Published: July 2009

The grain‐growth behavior and grain‐boundary structure in titanium‐excess BaTiO3 depend on the amount of excess titanium at 1250° and 1300°3C. With excess titanium, abnormal grain growth (AGG) occurs and the grain boundaries are mostly flat or faceted with hill‐and‐valley shapes. With 0.5 at.% excess titanium, the large grains have flat {111} faces forming singular grain boundaries parallel to {111} double twins. With excess‐titanium content between 0.1 and 0.3 at.%, the abnormal grains appear to have polyhedral shapes with {100} faces. These flat or faceted grain boundaries are expected to have singular structures, and hence AGG can occur by the step growth mechanism. When the excess‐titanium content is decreased to 0, the grain boundaries become curved, indicating a rough atomic structure, and normal grain growth occurs.
Microstructural Studies on the Low‐Temperature Crystallization Process of Strontium Bismuth Tantalate Thin Films
Authors: Ricote Jesús , Calzada M. Lourdes , González Ana , Ocal Carmen
Published: July 2009

The preparation of strontium bismuth tantalate (SBT) thin films at low temperatures for electronic applications is at present the subject of intense study. However, the microstructural evolution of these films has not been extensively reported, despite its importance in the determination of the final properties of the film. In this work, we study SBT thin films with various nominal compositions obtained by the crystallization at 650°3C of spin‐coated solutions on a silicon‐based substrate. Both the formation of the perovskite phase and the evolution of the grains are analyzed, with special attention to the formation of platelet‐like grains. A process of coalescence of initially round grains is proposed to explain the grain growth in this system. We also show that the use of a preannealing step inhibits the grain growth and, therefore, should be avoided. The role that the film thickness plays in the development of large grains is discussed.
Dense Mullite from Attrition‐Milled Kyanite and Aluminum Metal
Authors: Balmori‐Ramírez Heberto , Rocha‐Rangel Enrique , Refugio‐García Elizabeth , Bradt Richard C.
Published: July 2009

Dense mullite was produced through the reaction and sintering of an attrition‐milled mixture of kyanite (Al2O3·SiO2) and aluminum metal. Kyanite and aluminum were attrition‐milled then slowly heated at 1°3C/min to 1100°3C in air, and rapidly heated to 1600°3C and held for 1 h. During heating, the aluminum metal is oxidized first in the solid state and then as a liquid. The attrition‐milled kyanite decomposes yielding mullite and rejecting silica, which then reacts with the alumina formed from oxidation of the aluminum. Expansion from the aluminum oxidation and kyanite decomposition partially compensates for the normal sintering shrinkage. A dense, fine‐grain‐size mullite results.
Synthesis of Boron Nitride Coating on Carbon Nanotubes
Authors: Chen Linlin , Ye Haihui , Gogotsi Yury
Published: July 2009

A method to synthesize boron nitride coating on the surface of carbon nanotubes (nanofibers) without damaging the tube walls has been developed. A reaction between boric acid and ammonia was performed at moderate temperatures on the surface of carbon nanotubes to form boron nitride (BN) coatings. The surface structure of the carbon nanotubes significantly influences the morphology of the boron nitride coating. If the surface of the tubes is free of defects, highly crystallized insulating BN nanotubes can encapsulate carbon nanotubes. On the surface of carbon nanotubes with disordered wall structure, a polycrystalline BN sheath was produced.
Novel Microcellular Ceramics from a Silicone Resin
Authors: Colombo Paolo , Bernardo Enrico , Biasetto Lisa
Published: July 2009

Microcellular silicon oxycarbide open cell ceramic foams were fabricated from a silicone resin. Microcellular foams, with a cell size ranging from ∼1–80 μm, were fabricated using poly(methyl methacrylate) microbeads as sacrificial templates. The compression strength of the foams decreased with increasing cell size.
Large Photoinduced Densification in Organically Modified Germanosilicate Glasses
Authors: Jang Jae Hyeok , Kang Dong Jun , Bae Byeong‐Soo
Published: July 2009

Organically modified germanosilicate (ORMOGSIL) glasses prepared by a sol‐gel method showed a large refractive index change on ultraviolet exposure. The large photoinduced refractive index change in the ORMOGSIL glasses is mainly due to the structural densification caused by ultraviolet irradiation. The shifts in frequency of the Raman bands measured at room temperature reveal structural densification by reduction of the average intertetrahedral bonding angle θ in the ORMOGSIL glasses. Surface relief patterns by photoinduced densification were directly inscribed on the ORMOGSIL glasses.
Oxygen‐Deficient Anatase Precipitated from High‐Temperature Plasma
Authors: Kato Yoshikiyo , Yokobayashi Hiroko , Kasuya Atsuo , Kagawa Masahiro , Kawasaki Masashi
Published: July 2009

Feeding atomized aqueous solutions containing TiCl4 into an argon high‐temperature inductively coupled plasma (ICP) resulted in the formation of mixtures of white and blue particles. The mixtures consisted of anatase and an extra phase of rutile. Adding oxygen to the ICP led to the production of a single phase of white anatase. The blue particles could be characterized as oxygen‐deficient anatase. Electrophoretic mobility measurements indicated that Na+ participated in determining the surface potential of the mixtures. The oxygen defects may provide the adsorption sites to Na+.
Effects of Fluids on the Simulated Clinical‐Dental Machining of a Glass Ceramic
Authors: Yin Ling , Ives Lewis K. , Jahanmir Said
Published: July 2009

Effects of fluids on material removal rate, chipping damage, and surface roughness in the simulated clinical‐dental machining of a dental‐type glass ceramic were investigated. Significant differences in removal rate were obtained among the fluids investigated, but only a 4 wt% boric acid solution gave a higher removal rate than conventionally used water. Chipping damage was substantially lower for the boric acid and an oil‐emulsion coolant compared with other fluids tested. Surface roughness was independent of the fluids used. The results indicate that improvement can be achieved in both material removal rate and machining damage by the appropriate selection of coolant chemistry.
Effect of Dispersant Concentration on Preparation of an Ultrahigh Density ZnO–Al2O3 Target by Slip Casting
Authors: Sun YiHua , Xiong WeiHao , Li ChenHui , Yuan Lu
Published: July 2009

The rheological behavior of concentrated ZnO–Al2O3 aqueous suspensions has been studied in order to obtain an ultrahigh‐density ZnO–Al2O3 composite ceramic target by slip casting. The influence of the mass fraction of polyacrylic acid (PAA) on the fluidity of slurries and the density and strength of the green and sintered bodies was investigated. The slurries exhibited a near‐Newtonian flow behavior and had a lower viscosity with 0.3 wt% PAA. The excess of PAA enhanced the green strength and the density and strength of the sintered bodies. An ultrahigh density sintered body (>99.7% theoretical density) could be obtained after pressureless sintering at 1400°C. The Al species were well distributed in the sintered bodies, which showed a homogeneous, defect‐free microstructure with no abnormal grain growth.
Effect of Li2CO3 Addition on the Sintering Temperature and Microwave Dielectric Properties of Mg2V2O7 Ceramics
Authors: Joung Mi‐Ri , Kim Jin‐Seong , Song Myung‐Eun , Choi Jae‐Hong , Sun Jong‐Woo , Nahm Sahn , Paik Jong‐Hoo , Choi Byung‐Hyun
Published: July 2009

Li2CO3 was added to Mg2V2O7 ceramics in order to reduce the sintering temperature to below 900°C. At temperatures below 900°C, a liquid phase was formed during sintering, which assisted the densification of the specimens. The addition of Li2CO3 changed the crystal structure of Mg2V2O7 ceramics from triclinic to monoclinic. The 6.0 mol% Li2CO3‐added Mg2V2O7 ceramic was well sintered at 800°C with a high density and good microwave dielectric properties of ɛr=8.2, Q×f=70 621 GHz, and τf=−35.2 ppm/°C. Silver did not react with the 6.0 mol% Li2CO3‐added Mg2V2O7 ceramic at 800°C. Therefore, this ceramic is a good candidate material in low‐temperature co‐fired ceramic multilayer devices.
Er‐Doped Y2O3 Nanoparticles: A Comparison of Different Synthesis Methods
Authors: Kokuoz Basak Yazgan , Serivalsatit Karn , Kokuoz Baris , Geiculescu Olt , McCormick Exley , Ballato John
Published: July 2009

Nanoparticles of erbium‐doped yttria (Er:Y2O3) are important precursors to transparent ceramics for high‐power solid‐state lasers systems. As structure influences properties and, subsequently, performance the purpose of this work is to compare the morphological and chemical nature of the nanoparticles synthesized using two common methods: solution precipitation and combustion synthesis. A thorough characterization of as‐prepared and calcined powders was performed using Fourier transform infrared spectroscopy, X‐ray diffraction, conventional and high‐resolution transmission electron microscopy, and Brunauer–Emmet–Teller methods. Solution precipitation was found to lead to two different precursor compositions (yttrium carbonate or yttrium hydroxide) depending on the precipitating reagent whereas combustion synthesis yielded only phase‐pure, cubic Er:Y2O3. The hydroxide precipitation and combustion synthesis methods exhibited agglomerated particles with low surface area after calcining the precursors at 900°C. The addition of a small amount of ammonium sulfate during combustion synthesis was found to reduce the level of agglomeration, resultant particle size, and degree of crystallinity of the calcined Er:Y2O3 nanoparticles. The amount of carbon dioxide (CO2) and water (H2O) on the surface of the Er:Y2O3 powders is dependent on the powder surface area, however, increasing levels of gas absorption on the particle surfaces do not have a detrimental effect on the sinterability. The sintered density increases with increasing surface area and decreasing agglomeration.
Perineal extramammary Paget disease responsive to topical imiquimod
Authors: Cecchi Roberto , Pavesi Mario , Bartoli Laura , Brunetti Luigi , Rapicano Valentina
Published: July 2009

Extramammary Paget disease (EMPD) is a rare neoplasm that arises in skin rich in apocrine glands, such as the axillae and anogenital region and usually affects the elderly. In most cases, EMPD is an apocrine carcinoma in situ, but it can be associated with internal malignancy spreading to overlying skin. Surgical excision with margin control is the generally accepted standard of care. A 74‐year‐old woman presented with a 1 year history of a pruritic eczematous eruption in perineum which on biopsy was diagnosed as EMPD. Because of the location and extent of the tumor, any surgical approach would have been problematic. Imiquimod 5% cream applied three times weekly for 16 weeks induced complete resolution. Topical imiquimod appears to be a promising treatment option for EMPD, especially when surgery is a challenge, but only a few cases have been reported.
Connective Tissue Growth Factor Knockdown Attenuated Matrix Protein Production and Vascular Endothelial Growth Factor Expression Induced by Transforming Growth Factor‐β1 in Cultured Human Peritoneal Mesothelial Cells
Authors: Xiao Li , Sun Lin , Liu Fu‐You , Peng You‐Ming , Duan Shao‐Bin
Published: July 2009

Connective tissue growth factor (CTGF), a downstream mediator of transforming growth factor‐β1 (TGF‐β1) inducing fibrosis, has recently been implicated in peritoneal fibrosis. Extracellular matrix (ECM) accumulation and angiogenesis are characteristic changes in peritoneal fibrosis. In this study we investigated the effect of CTGF knockdown via interference RNA (RNAi) on ECM production and vascular endothelial growth factor (VEGF) expression induced by TGF‐β1 in human peritoneal mesothelial cells (HPMCs). Four CTGF short hairpin RNA (shRNA) expression constructs were generated using the pRetroSuper vector, and infectious retroviral particles were prepared to infect HPMCs. Expression levels of CTGF, fibronectin(FN), collagen 1 (col 1), laminin, and VEGF mRNA and protein were measured by semi‐quantitative reverse transcription polymerase chain reaction and western blot assay. CTGF expression was increased after stimulation with TGF‐β1, but inhibited using each of the four independent CTGF shRNA constructs (P < 0.01). Moreover, expression of ECM proteins (FN, col 1, and laminin) and VEGF were upregulated after incubation with TGF‐β1, but elevated levels of ECM and VEGF induced by TGF‐β1 were significantly inhibited by RNAi (P < 0.01), but not by the empty retroviral vector (P > 0.05). From these results, we concluded that retrovirus‐mediated CTGF shRNA can effectively inhibit ECM production and VEGF expression induced by TGF‐β1 in HPMCs. This study suggests that downregulation of CTGF may represent a potential therapeutic approach for peritoneal fibrosis through decreasing ECM accumulation and angiogenesis.
Acute and Subacute Effect of Rheopheresis on Microvascular Endothelial Function in Patients Suffering From Age‐related Macular Degeneration
Authors: Rossi Marco , Puccini Rodolfo , Romagnoli Maria Chiara , Di Maria Cinzia , Mattei Paola , Bernini Matteo , Marconcini Claudio , Santoro Gino
Published: July 2009

This study was performed on seven patients affected by the atrophic form of age‐related macular degeneration (AF‐ARMD). The patients under investigation belonged to a larger study aimed at evaluating the efficacy of rheopheresis treatment (RT) on the visual function of AF‐ARMD patients. Following the protocol of the larger study, patients received RT twice a week, every two weeks, for a total of ten treatments, as well as high‐dose supplementation with zinc and vitamins A, E and beta‐carotene. Recruited patients underwent skin laser Doppler flowmetry coupled with skin iontophoresis of the endothelium‐dependent vasodilator acetylcholine (ACh) and a test of skin post‐ischemic reactive hyperemia, before and after the first RT (time 1: all seven patients) and the fifth RT (time 2: six patients). A significantly higher absolute (anova for repeated measures) and relative (percentage change from the baseline) skin blood flux response (SBFR) to ACh iontophoresis was observed after RT, compared to before RT at time 1 (679 ± 43% and 436 ± 78%, respectively; P < 0.05), as well as before RT at time 2 compared to before RT at time 1 (683 ± 74% and 436 ± 78%, respectively; P < 0.05). Absolute and relative SBFR to ischemia did not differ either after RT compared to before RT at time 1, or before RT at time 2 compared to before RT at time 1. These findings are consistent with an acute and subacute beneficial effect of RT on skin microvascular endothelial function in the studied AF‐ARMD patients.
REMOVAL OF LIPID FROM SURFACES OF ROASTED PEANUTS BY SONICATION AS ASSESSED BY FLUORESCENCE AND SCANNING ELECTRON MICROSCOPY
Authors: WAMBURA PETER , YANG WADE , MWAKATAGE NASSON , HERRING JOSHUA L.
Published: July 2009

Peanut oil migrates to the outer surface during roasting, where it comes into contact with oxygen, leading to the oxidation reactions. Because of its cleaning effect, power ultrasound (sonication) was used for removing surface lipid of roasted peanuts. Georgia green runner‐type peanuts were roasted at 178C for 15 min. Roasted peanuts were subjected to lipid extraction in n‐hexane by sonication. Fluorescent and electron scanning micrographs revealed that the surface of sonicated peanuts was free of oil stains, as opposed to that of freshly roasted peanuts. These results showed that power ultrasound could remove the lipids from peanut surfaces very effectively. Details of microstructure of sonicated peanuts as was observed using scanning electron microscope reveal that 10 min sonication was sufficient to extract most of the lipids on the roasted peanut surfaces. Fluorescence and scanning electron microscopy are useful in peanut analysis because they can detect lipids in low concentration.

PRACTICAL APPLICATIONS

There is increasing interest of quick procedures to examine the surfaces of roasted peanut samples after undergoing treatments, such as removal of lipids. This research demonstrated the significant use of fluorescent and scanning electron microscopes to quickly study the extent of lipid removal from the surface of roasted peanuts after power ultrasound treatment (sonication).
COMPOSITION OF SUPERCRITICAL CARBON DIOXIDE EXTRACTS OF PITANGA (EUGENIA UNIFLORA L.) LEAVES
Authors: PEIXOTO CAMILA A. , OLIVEIRA ALESSANDRA L. , CABRAL FERNANDO A.
Published: July 2009

The leaves of the Pitanga bush (Eugenia uniflora L.) are considered to be effective against many diseases. Extracts from Pitanga leaves have been found to show pronounced anti‐inflammatory action and to have antimicrobial and antifungal activities, among other properties. In this work, extracts from Pitanga leaves were obtained by hydrodistillation and by extraction with supercritical carbon dioxide (SC‐CO2) at three conditions of temperature and pressure. In the SC‐CO2 extractions also were collected the components that are lost with the CO2 in the exit of the system using Porapak‐Q polymer trap. All extracts were analyzed by gas chromatography‐mass spectrometry (GC‐MS). Thirty‐nine compounds were found in the extracts and twenty‐six were identified. The main components identified in the extracts in decreasing quantitative order were: curzerene, germacrene B, C15H20O2 andβ‐elemene for hydrodistillation; C15H20O2 and curzerene for SC‐CO2 extracts and 3‐hexen‐1‐ol, curzerene, C15H20O2,β‐elemene and germacrene B for SC‐CO2 extracts captured in Porapak‐Q.

PRACTICAL APPLICATIONS

The natural extracts are a potential source of compounds possessing biological activities. They can be used in foods, pharmaceutics and cosmetics. Pitanga is an exotic fruit from Brazil and extracts from its leaves have been used against many diseases in Brazilian folk medicine. Supercritical extraction is an interesting process for the production of natural extracts because it is a clean process and the knowledge of composition of extracts is crucial for the identification of the probable active components.
OPTIMIZATION OF MUCILAGE EXTRACTION FROM QODUME SHIRAZI SEED (ALYSSUM HOMOLOCARPUM) USING RESPONSE SURFACE METHODOLOGY
Authors: KOOCHEKI ARASH , MORTAZAVI SEYED A. , SHAHIDI FAKHRI , RAZAVI SEYED M. A. , KADKHODAEE RASOUL , MILANI JAFAR M.
Published: July 2009

Response surface methodology was used to determine the optimum processing conditions that yield maximum apparent viscosity and extraction yield and consistency coefficient with minimum protein content and flow behavior index during extraction of Qodume Shirazi seed gum. Extraction temperature (25–85C), pH (4–10) and water : seed (20:1–60:1) were the factors investigated. Experiments were designed according to Central Composite Face Center Design with these three factors, including central and axial points. The response surfaces showing the interaction of process variables were constructed. Solution with 3% concentration of each gum with different extraction methods were made to evaluate the flow properties of gum extracted from Qodume seeds. The Power‐law model was successfully applied to fit the shear stress versus shear rate data of gum solution. The flow behavior indices, n, varied in the range of 0.25–0.41. The consistency coefficients, k, were in the range of 5.5–8.62 Pa·sn. Applying desirability function method, optimum operating conditions were found to be extraction temperature of 36.3C, pH of 4 and water : seed of 40:1. At this optimum point, apparent viscosity, extraction yield and protein content, consistency coefficient, flow behavior index were found to be 855.9 (mPa·s), 287.3 (g/kg), 1.27 (%), 8.27 (Pa·sn) and 0.29, respectively.

PRACTICAL APPLICATIONS

Growing use of hydrocolloids in food industries has brought about the need for new sources of these products. Therefore, there could be a substantial market for new source of produced gum. The aim of the present paper was to choose a suitable new source for extracting polysaccharides. Qodume Shirazi is a medicinal seed grown in the Middle East that produces a high amount of mucilage. Thus we optimized the best method for extraction of mucilage from this seed, which is important for producing gum from Qodume Shirazi and assessed the flow behavior of the gum.
An Expressed
Fgf4
Retrogene Is Associated with Breed-Defining Chondrodysplasia in Domestic Dogs
Authors: Parker Heidi G. , VonHoldt Bridgett M. , Quignon Pascale , Margulies Elliott H. , Shao Stephanie , Mosher Dana S. , Spady Tyrone C. , Elkahloun Abdel , Cargill Michele , Jones Paul G. , Maslen Cheryl L. , Acland Gregory M. , Sutter Nathan B. , Kuroki Keiichi , Bustamante Carlos D. , Wayne Robert K. , Ostrander Elaine A.
Published: July 2009

Going Retro

In a year celebrating Darwin, the question of how new functional genes arise during evolution is of particular interest. Through a multibreed genetic analysis of the domestic dog,

Parker
et al.

(p.
995
, published online 16 July; see the Perspective by

Kaessmann

) find that the short-legged phenotype that characterizes at least 19 common dog breeds, including the corgi, dachshund, and basset hound, is specifically associated with the expression in developing bone of a gene encoding fibroblast growth factor 4 (
fgf4
), a member of a gene family previously implicated in dwarfism in humans. Interestingly, the culprit
fgf4
gene in dogs has the hallmarks of a “retrogene,” a gene that arises when a parental gene is duplicated through an RNA-based copying mechanism.
Exploring Dark Matter with Milky Way Substructure
Authors: Kuhlen Michael , Madau Piero , Silk Joseph
Published: July 2009

Toward Detecting Dark Matter Signals

Dark matter, whose presence has been inferred indirectly through its gravitational effects on luminous matter, is thought to hold galaxies together and may form most of the matter in the universe. Although its nature is still unknown, theoretical models predict that when certain dark matter particles collide, they annihilate, producing gamma rays. Using a numerical simulation of a galaxy the size of the Milky Way,

Kuhlen
et al.

(p.
970
, published online 16 July) investigated the potential signals from dark matter in our galaxy, for the case in which the annihilation rate is boosted by an attractive force between incident dark matter particles. If this enhancement effect is valid, hundreds of dark matter clumps in our galaxy should be detected by the Fermi Gamma-ray Space Telescope.
Bcl6 and Blimp-1 Are Reciprocal and Antagonistic Regulators of T Follicular Helper Cell Differentiation
Authors: Johnston Robert J. , Poholek Amanda C. , DiToro Daniel , Yusuf Isharat , Eto Danelle , Barnett Burton , Dent Alexander L. , Craft Joe , Crotty Shane
Published: July 2009

T Follicular Helper Cell Differentiation

When B cells respond to an infection, they often require help from CD4
+
T cells to mount a proper response. It is thought that a subset of CD4
+
effector T cells, called T follicular helper cells (T
FH
), performs this function. Several subsets of effector CD4
+
T cells arise, depending on the type of infection, which have distinct transcriptional programs driving their differentiation. Whether this is also the case for T
FH
cells has not been clear (see the Perspective by

Awasthi and Kuchroo

).

Nurieva
et al.

(p.
1001
, published online 23 July) and

Johnston
et al.

(p.
1006
; published online 16 July) now demonstrate that the transcription factor Bcl6 is both necessary and sufficient for T
FH
differentiation and subsequent B cell–mediated immunity, suggesting that it is a master regulator of this lineage. Johnston
et al.
also show that expression of Bcl6 and the transcription factor, Blimp-1, are reciprocally regulated in T
FH
cells and that, when ectopically expressed, Blimp-1 inhibits T
FH
development.
Mindblind Eyes: An Absence of Spontaneous Theory of Mind in Asperger Syndrome
Authors: Senju Atsushi , Southgate Victoria , White Sarah , Frith Uta
Published: July 2009

Diverting Asperger Deficit

Placement of Asperger syndrome within the family of autism spectrum disorders (ASD) has always been a bit uneasy; although people with Asperger syndrome do exhibit the core impairments in social interaction and communication that are characteristic of ASD, they nevertheless perform well on tests that are thought to assess the ability to mentalize or to possess Theory of Mind skills. One of the classic tests of mentalizing ability is the false-belief task, in which subjects must be able to represent their own beliefs (true) and another's beliefs, which are false because they have not been given complete information, such as not having seen the transfer of a piece of candy from one drawer to another. People with Asperger syndrome succeed at the verbal form of the false-belief task, yet

Senju
et al.

(p.
883
, published online 16 July) show that this is owing entirely to their having learned how to cope with an existing and still demonstrable deficit in an implicit version of the false-belief task. That is, the core impairment is present, but conscious and explicit learning allows them to compensate.
Effects of essential fatty acid deficiency on enterohepatic circulation of bile salts in mice
Authors: Lukovac S. , Los E. L. , Stellaard F. , Rings E. H. H. M. , Verkade H. J.
Published: July 2009

Essential fatty acid (EFA) deficiency in mice has been associated with increased bile production, which is mainly determined by the enterohepatic circulation (EHC) of bile salts. To establish the mechanism underlying the increased bile production, we characterized in detail the EHC of bile salts in EFA-deficient mice using stable isotope technique, without interrupting the normal EHC. Farnesoid X receptor (FXR) has been proposed as an important regulator of bile salt synthesis and homeostasis. In Fxr−/−mice we additionally investigated to what extent alterations in bile production during EFA deficiency were FXR dependent. Furthermore, we tested in differentiating Caco-2 cells the effects of EFA deficiency on expression of FXR-target genes relevant for feedback regulation of bile salt synthesis. EFA deficiency-enhanced bile flow and biliary bile salt secretion were associated with elevated bile salt pool size and synthesis rate (+146 and +42%, respectively, P < 0.05), despite increased ileal bile salt reabsorption (+228%, P < 0.05). Cyp7a1 mRNA expression was unaffected in EFA-deficient mice. However, ileal mRNA expression of Fgf15 (inhibitor of bile salt synthesis) was significantly reduced, in agreement with absent inhibition of the hepatic bile salt synthesis. Bile flow and biliary secretion were enhanced to the same extent in EFA-deficient wild-type and Fxr−/−mice, indicating contribution of other factors besides FXR in regulation of EHC during EFA deficiency. In vitro experiments show reduced induction of mRNA expression of relevant genes upon chenodeoxycholic acid and a selective FXR agonist GW4064 stimulation in EFA-deficient Caco-2 cells. In conclusion, our data indicate that EFA deficiency is associated with interrupted negative feedback of bile salt synthesis, possibly because of reduced ileal Fgf15 expression.
Epidermal growth factor receptor regulates pancreatic fibrosis
Authors: Blaine Stacy A. , Ray Kevin C. , Branch Kevin M. , Robinson Pamela S. , Whitehead Robert H. , Means Anna L.
Published: July 2009

The development of pancreatic fibrosis has been shown to be a major component in several diseases of the pancreas including pancreatic cancer, chronic pancreatitis, and type 2 diabetes mellitus, but its actual role in the progression of these disorders is still unknown. This fibrosis is characterized by stromal expansion and the excessive deposition of extracellular matrix (ECM) that replaces pancreatic tissue. This eventually leads to dysregulation of ECM turnover, production of cytokines, restriction of blood flow, and often exocrine and endocrine insufficiencies. Activated pancreatic stellate cells (PSCs) have been identified as key mediators in the progression of pancreatic fibrosis, serving as the predominant source of excess ECM proteins. Previously, we found that overexpression of the growth factor heparin-binding epidermal growth factor-like growth factor (HB-EGF) in pancreatic islets led to intraislet fibrosis. HB-EGF binds to and activates two receptors, epidermal growth factor receptor (EGFR) and ErbB4, as well as heparin moieties and CD9/DRAP27. To understand the mechanism underlying the induction of fibrogenesis by HB-EGF, we utilized a hypomorphic allele of Egfr, the Waved-2 allele, to demonstrate that EGFR signaling regulates fibrogenesis in vivo. Using an in vitro cell migration assay, we show that HB-EGF regulates both chemoattraction and stimulation of proliferation of PSCs via EGFR activation.
Adiponectin-stimulated CXCL8 release in primary human hepatocytes is regulated by ERK1/ERK2, p38 MAPK, NF-κB, and STAT3 signaling pathways
Authors: Wanninger Josef , Neumeier Markus , Weigert Johanna , Bauer Sabrina , Weiss Thomas S. , Schäffler Andreas , Krempl Corinna , Bleyl Cornelia , Aslanidis Charalampos , Schölmerich Jürgen , Buechler Christa
Published: July 2009

Adiponectin is believed to exert hepatoprotective effects and induces CXCL8, a chemokine that functions as a survival factor, in vascular cells. In the current study, it is demonstrated that adiponectin also induces CXCL8 expression in primary human hepatocytes but not in hepatocellular carcinoma cell lines. Knock down of the adiponectin receptor (AdipoR) 1 or AdipoR2 by small-interfering RNA indicates that AdipoR1 is involved in adiponectin-stimulated CXCL8 release. Adiponectin activates nuclear factor (NF)-κB in primary hepatocytes and pharmacological inhibition of NF-κB, the p38 mitogen-activated protein kinase, and extracellular signal-regulated kinase (ERK) 1/ERK2 reduces adiponectin-mediated CXCL8 secretion. Furthermore, adiponectin also activates STAT3 involved in interleukin (IL)-6 and leptin-mediated CXCL8 induction in primary hepatocytes. Inhibition of JAK2 by AG-490 does not abolish adiponectin-stimulated CXCL8, indicating that this kinase is not involved. Pretreatment of primary cells with “STAT3 Inhibitor VI,” however, elevates hepatocytic CXCL8 secretion, demonstrating that STAT3 is a negative regulator of CXCL8 in these cells. In accordance with this assumption, IL-6, a well-characterized activator of STAT3, reduces hepatocytic CXCL8. Therefore, adiponectin-stimulated induction of CXCL8 seems to be tightly controlled in primary human hepatocytes, whereas neither NF-κB, STAT3, nor CXCL8 are influenced in hepatocytic cell lines. CXCL8 is a survival factor, and its upregulation by adiponectin may contribute to the hepatoprotective effects of this adipokine.
Established neointimal hyperplasia in vein grafts expands via TGF-β-mediated progressive fibrosis
Authors: Jiang Zhihua , Tao Ming , Omalley Kerri A. , Wang Danlu , Ozaki C. Keith , Berceli Scott A.
Published: July 2009

In weeks to months following implantation, neointimal hyperplasia (NIH) in vein grafts (VGs) transitions from a cellularized to a decellularized phenotype. The inhibition of early cellular proliferation failed to improve long-term VG patency. We have previously demonstrated that transforming growth factor-β1 (TGF-β1)/connective tissue growth factor (CTGF) pathways mediate a conversion of fibroblasts to myofibroblasts in the early VG (<2 wk). We hypothesize that these similar pathways drive fibrosis observed in the late VG lesion. Within rabbit VGs, real-time RT-PCR, Western blot analysis, ELISA, and immunohistochemistry were used to examine TGF-β/CTGF pathways in late (1–6 mo) NIH. All VGs exhibited a steady NIH growth ( P = 0.006) with significant reduction in cellularity ( P = 0.01) over time. Substantial TGF-β profibrotic activities, as evidenced by enhanced TGF-β1 activation, TGF-β receptor types I (activin receptor-like kinase 5)-to-II receptor ratio, SMAD2/3 phosphorylation, and CTGF production, persisted throughout the observation period. An increased matrix synthesis was accompanied by a temporal reduction of matrix metalloproteinase-2 ( P = 0.001) and -9 ( P < 0.001) activity. VG NIH is characterized by a conversion from a proproliferative to a profibrotic morphology. An enhanced signaling via TGF-β/CTGF coupled with reduced matrix metalloproteinase activities promotes progressive fibrotic NIH expansion. The modulation of late TGF-β/CTGF signaling may offer a novel therapeutic strategy to improve the long-term VG durability.
Chronic central versus systemic blockade of AT1 receptors and cardiac dysfunction in rats post-myocardial infarction
Authors: Huang Bing S. , Ahmad Monir , Tan Junhui , Leenen Frans H. H.
Published: July 2009

In rats, both central and systemic ANG II type 1 (AT1) receptor blockade attenuate sympathetic hyperactivity, but central blockade more effectively attenuates left ventricular (LV) dysfunction post-myocardial infarction (MI). In protocol I, we examined whether functional effects on cardiac load may play a role and different cardiac effects disappear after withdrawal of the blockade. Wistar rats were infused for 4 wk post-MI intracerebroventricularly (1 mg·kg−1·day−1) or injected subcutaneously daily (100 mg·kg−1·day−1) with losartan. LV dimensions and function were assessed at 4 wk and at 6 wk post-MI, i.e., 2 wk after discontinuing treatments. At 4 and 6 wk post-MI, LV dimensions were increased and ejection fraction was decreased. Intracerebroventricular but not subcutaneous losartan significantly improved these parameters. At 6 wk, LV peak systolic pressure (LVPSP) and maximal or minimal first derivative of change in pressure over time (dP/d tmax/min) were decreased and LV end-diastolic pressure (LVEDP) was increased. All four indexes were improved by previous intracerebroventricular losartan, whereas subcutaneous losartan improved LVEDP only. In protocol II, we evaluated effects of oral instead of subcutaneous administration of losartan for 4 wk post-MI. Losartan (∼200 mg·kg−1·day−1) either via drinking water or by gavage similarly decreased AT1 receptor binding densities in brain nuclei and improved LVEDP but further decreased LVPSP and dP/d tmax. These results indicate that effects on cardiac load by peripheral AT1 receptor blockade or the pharmacokinetic profile of subcutaneous versus oral dosing do not contribute to the different cardiac effects of central versus systemic AT1 receptor blockade post-MI.
Sodium tanshinone IIA sulfonate increased intestinal hemodynamics without systemic circulatory changes in healthy newborn piglets
Authors: Liu Jiangqin , Morton Jude , Miedzyblocki Margaret , Lee Tze Fun , Bigam David L. , Fok Tai Fai , Chen Chao , Lee Shoo K. , Davidge Sandra T. , Cheung Po-Yin
Published: July 2009

In traditional Chinese medicine, tanshinone IIA is a lipid-soluble component of Danshen that has been widely used for various cardiovascular and cerebrovascular disorders, including neonatal asphyxia. Despite promising effects, little is known regarding the hemodynamic effects of tanshinone IIA in newborn subjects. To examine the dose-response effects of sodium tanshinone IIA sulfonate (STS) on systemic and regional hemodynamics and oxygen transport, 12 newborn piglets were anesthetized and acutely instrumented for the placement of femoral arterial and venous, pulmonary arterial catheters to measure mean arterial, central venous, and pulmonary arterial pressures, respectively. The blood flow at the common carotid, renal, pulmonary, and superior mesenteric (SMA) arteries were continuously monitored after treating the piglets with either STS (0.1–30 mg/kg iv) or saline treatment ( n = 6/group). To further delineate the underlying mechanisms for vasorelaxant effects of STS, in vitro vascular myography was carried out to compare its effect on rat mesenteric and carotid arteries ( n = 4–5/group). STS dose-dependently increased the SMA blood flow and the corresponding oxygen delivery with no significant effect on systemic and pulmonary, carotid and renal hemodynamic parameters. In vitro studies also demonstrated that STS selectively dilated rat mesenteric but not carotid arteries. Vasodilation in mesenteric arteries was inhibited by apamin and TRAM-34 (calcium-activated potassium channel inhibitors) but not by meclofenamate (cyclooxygenase inhibitor) or N-nitro-l-arginine methyl ester hydrochloride (nitric oxide synthase inhibitor). In summary, without significant hemodynamic effects on newborn piglets, intravenous infusion of STS selectively increased mesenteric perfusion in a dose-dependent manner, possibly via an endothelium-derived hyperpolarizing factor vasodilating pathway.
Stabilizing immature breathing patterns of preterm infants using stochastic mechanosensory stimulation
Authors: Bloch-Salisbury Elisabeth , Indic Premananda , Bednarek Frank , Paydarfar David
Published: July 2009

Breathing patterns in preterm infants consist of highly variable interbreath intervals (IBIs) that might originate from nonlinear properties of the respiratory oscillator and its input-output responses to peripheral and central signals. Here, we explore a property of nonlinear control, the potential for large improvement in the stability of breathing using low-level exogenous stochastic stimulation. Stimulation was administered to 10 preterm infants (postconceptional age: mean 33.3 wk, SD 1.7) using a mattress with embedded actuators that delivered small stochastic displacements (0.021 mm root mean square, 0.090 mm maximum, 30–60 Hz); this stimulus was subthreshold for causing arousal from sleep to wakefulness or other detectable changes in the behavioral state evaluated with polysomnography. We used a test-retest protocol with multiple 10-min intervals of stimulation, each paired with 10-min intervals of no stimulation. Stimulation induced an ∼50% reduction ( P = 0.003) in the variance of IBIs and an ∼50% reduction ( P = 0.002) in the incidence of IBIs > 5 s. The improved stability of eupneic breathing was associated with an ∼65% reduction ( P = 0.04) in the duration of O2desaturation. Our findings suggest that nonlinear properties of the immature respiratory control system can be harnessed using afferent stimuli to stabilize eupneic breathing, thereby potentially reducing the incidence of apnea and hypoxia.
Regional CO2tension quantitatively mediates homeostatic redistribution of ventilation following acute pulmonary thromboembolism in pigs
Authors: Tsang John Y. C. , Lamm Wayne J. E. , Swenson Erik R.
Published: July 2009

Previous studies reported that regional CO2tension might affect regional ventilation (V̇) following acute pulmonary thromboembolism (APTE). We investigated the pathophysiology and magnitude of these changes. Eight anesthetized and ventilated piglets received autologous clots at time = 0 min until mean pulmonary artery pressure was 2.5 times baseline. The distribution of V̇ and perfusion (Q̇) at four different times (−5, 30, 60, 120 min) was mapped by fluorescent microspheres. Regional V̇ and Q̇ were examined postmortem by sectioning the air-dried lung into 900–1,000 samples of ∼2 cm3each. After the redistribution of regional Q̇ by APTE, but in the scenario assuming that no V̇ shift had yet occurred, CO2tension in different lung regions at 30 min post-APTE (PXCO2) was estimated from the V̇/Q̇ data and divided into four distinct clusters: i.e., PXCO2< 10 Torr; 10 < PXCO2< 25 Torr; 25 < PXCO2< 50 Torr; PXCO2> 50 Torr. Our data showed that the clusters in higher V̇/Q̇ regions (with a PXCO2< 25 Torr) received ∼35% less V̇ when measured within 30 min of APTE, whereas, in contrast, the lower V̇/Q̇ regions showed no statistically significant increases in their V̇. However, after 30 min, there was minimal further redistribution of V̇. We conclude that there are significant compensatory V̇ shifts out of regions of low CO2tension soon following APTE, and that these variations in regional CO2tension, which initiate CO2-dependent changes in airway resistance and lung parenchymal compliance, can lead to improved gas exchange.
Hepatic VLDL assembly is disturbed in a rat model of nonalcoholic fatty liver disease: is there a role for dietary coenzyme Q?
Authors: Cano Ainara , Ciaffoni Fiorella , Safwat Ghada M. , Aspichueta Patricia , Ochoa Begoña , Bravo Elena , Botham Kathleen M.
Published: July 2009

The overproduction of very-low-density lipoprotein (VLDL) is a characteristic feature of nonalcoholic fatty liver disease (NAFLD). The aim of this study was to use a high-fat diet-induced model of NAFLD in rats to investigate 1) the influence of the disease on hepatic VLDL processing in the endoplasmic reticulum and 2) the potential modulatory effects of dietary coenzyme Q (CoQ). Rats were fed a standard low-fat diet (control) or a diet containing 35% fat (57% metabolizable energy). After 10 wk, high-fat diet-fed animals were divided into three groups: the first group was given CoQ9 (30 mg·kg body wt−1·day−1in 0.3 ml olive oil), the second group was given olive oil (0.3 ml/day) only, and the third group received no supplements. Feeding (3 high-fat diets and the control diet) was then continued for 8 wk. In all high-fat diet-fed groups, the content of triacylglycerol (TG) and cholesterol in plasma VLDL, the liver, and liver microsomes was increased, hepatic levels of apolipoprotein B48 were raised, and the activities of microsomal TG transfer protein and acyl CoA:cholesterol acyltransferase were reduced. These findings provide new evidence indicating that VLDL assembly and the inherent TG transfer to the endoplasmic reticulum are altered in NAFLD and suggest a possible explanation for both the overproduction of VLDL associated with the condition and the disease etiology itself. Dietary CoQ caused significant increases in apolipoprotein B mRNA and microsomal TG levels and altered the phospholipid content of microsomal membranes. These changes, however, may not be beneficial as they may lead to the secretion of larger, more atherogenic VLDL.