bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility of Calcium in CaCl2-CaO
Authors: Shaw Stephen , Watson Robert
Published: August 2009

The solubility of calcium in calcium chloride - calcium oxide is of interest in processes reducing metal oxides in calcium chloride based salt systems. The solubility of calcium in calcium chloride was measured as 2.7mol% at 1073K. This reduced to 0.4mol% at a calcium oxide content of 9.0mol%. Experimental data for the binary components of the calcium - calcium chloride - calcium oxide ternary system has been used to construct a model of the ternary system, against which the results reported here are compared. At high calcium oxide concentrations there is reasonable agreement between model and experiment; at low calcium oxide concentrations the model predicts lower calcium concentrations than found experimentally.
Diffusion Kinetics for the Electrochemical Reduction of Fe (III) Species in Molten NaCl-FeCl3
Authors: Haarberg Geir Martin , Keppert Martin
Published: August 2009

The electrochemical behaviour of dissolved FeCl3 was studied in molten NaCl at 890 oC. Dissolved Fe (III) was found to be stable and was reduced to metallic Fe in a diffusion controlled reaction. The diffusion coefficient for Fe (III) was determined to be 1.4 x 10-9 m2 s-1 from linear sweep voltammetry.
Electrical conductivity of the (KF-AlF3)-NaF-LiF Molten System with Al2O3 additions at Low Cryolite Ratio
Authors: Dedyukhin Alexander , Apisarov Alexei , Tkacheva Olga , Redkin Alexander A. , Zaikov Yurii , Frolov Anton , Gusev Alexander
Published: August 2009

The electrical conductivity of low temperature electrolytes for aluminum electrolysis has been measured. The potassium cryolite was the basic melt. Additions of LiF and NaF increased the conductivity of (KF +AlF3) molten mixtures but Al2O3 decreased it.
Inert Anodes for Oxygen Evolution in Molten Salts
Authors: Kvalheim Eirin , Haarberg Geir Martin , Martinez Ana Maria , Jahren Hans M.
Published: August 2009

Nickel ferrite based cermets were examined as possible materials for inert, oxygen evolving anodes in molten salt electrolysis. Four materials with varying contents of NiFe2O4, NiO, Ni and Cu were tested during 10 hours potentiostatic electrolysis in molten CaCl2-based electrolytes at 650{degree sign}C and 850{degree sign}C. It was found that the metal phase corroded during electrolysis. Small amounts of impurity metal were found in the cathode product. The current and potential as function of time showed a stable potential, but quite high current during electrolysis, probably due to corrosion of the metal phase of the anode. Adding excess NiO to the anode increased the performance of the anode, increasing density, stability of the nickel ferrite phase and perhaps increased catalytic activity towards oxygen evolution. Increasing the Ni/Cu ratio in the metal phase decreased the corrosion of the anode, but increased the anode potential.
Aluminum UPD and Alloy Formation on (111)-Textured Au in AlCl3-EMIC
Authors: Stafford Gery R. , Haarberg Geir Martin
Published: August 2009

The kinetics of Al-Au surface alloy formation was examined during Al underpotential deposition (upd) onto (111)-textured Au from Lewis acidic aluminum chloride - 1-ethyl-3-methylimidazolium chloride (AlCl3-EMImCl) using linear sweep stripping voltammetry following potentiostatic deposition. The upd of Al on Au is a two-step process, the first step may be the reductive decomposition of AlCl4- that is known to be adsorbed on the Au surface. Following completion of the Al monolayer, two alloys are formed. The first is only present at short times and is restricted to the near surface while the second is the more stable of the two and extends into the Au substrate. The upd of Al causes a negative (compressive) change in the surface stress; however the stress change becomes tensile in the region of alloy formation. The magnitude of the tensile stress change observed experimentally is close to that calculated from the elastic strain associated with the change in molar volume and from the reaction kinetics obtained from stripping voltammetry.
Distribution of Impurities during Vanadium Electrorefining and Determination of Optimal Conditions of the Process
Authors: Polovov Ilya B. , Chernyshov Mihail V. , Volkovich Vladimir A. , Nechkin Georgiy A. , Rebrin Oleg I. , Rylov Alexander N. , Griffiths Trevor R.
Published: August 2009

The process of vanadium electrolytic refining in NaCl-KCl melt was performed in the specially designed semi-industrial scale electrolyser. The method of experiments mathematic planning was used to determine the electrolysis optimal conditions. In a special series of industrial experiments distribution of metallic and non-metallic impurities during vanadium electrorefining was investigated. The optimal parameters of the electrolysis for producing 99.5% pure vanadium were determined and the requirements for purity of crude materials formulated.
Underpotential Deposition Modification of a Nanoporous Au Electrode Fabricated by Alloying/Dealloying in a Room Temperature Ionic Liquid
Authors: Huang Jing-Fang
Published: August 2009

This paper describes an electrochemical method for the modification of the nanoporous Au surface by using underpotentially deposited (UPD) metal adlayer. The nanoporous Au electrode was obtained by a dealloying process in a 40-60 mol % zinc chloride-1-ethyl-3-methylimidazolium chloride (ZnCl2-EMIC) ionic liquid. The surface characteristic of the nanoprous Au electrode is expected to be adjustable with the modification of various UPD metals.
Electrochemical Studies of Titanium Chlorides in Ionic Liquids
Authors: Cheek Graham T. , Canby Dana , O'Grady William
Published: August 2009

The voltammetric behavior of TiCl4 has been investigated in the room-temperature ionic liquid 1-butyl-1-methylpyrrolidinium triflate (BMPY TfO). In contrast to behavior observed in the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI BF4) system, the Ti3+/Ti4+ redox process occurs as a series of peaks corresponding to mixed triflate / chloride complexes. No adherent deposits were obtained at copper electrodes in BMPY TfO / TiCl4 solutions. Attempts to produce titanium deposits from titanium complexes of acetylacetonate and isopropoxide were also not successful.
Effect of CsF-concentration on Electrolytic Conductivity, Viscosity, and Anode Reaction of Nickel Electrode in (CH3)3N-CsF-HF System at Room Temperature
Authors: Tasaka Akimasa , Nakanishi Kenta , Masuda Noriaki , Nakai Takaaki , Momota Kunitaka , Inaba Minoru
Published: August 2009

In order to improve the curent efficiency for perfluorotrimethylamine, (CF3)3N, formation using the Ni anode, the mixed melts of (CH3)3N·mHF+CsF·2.3HF were used as an electrolyte at a room temperature. The electrolytic conductivity of the mixed melt decreased with an increase in the CsF-concentration, whereas the viscosity of the mixed melt increased with increasing the CsF-concentration. XRD analysis revealed that CsNi2F6 was present in the oxidized layer formed on the Ni anode in the mixed melts. The gas evolved at the Ni anode in the mixed melt of (CH3)3N·5.0HF and CsF·2.3HF was composed of (CF3)3N, (CF3)2CHF2N, CF3(CHF2)2N, (CHF2)3N, CF4, NF3, CHF3, C2HF5, and C2F6. The best ratio of (CF3)3N to total anode gas was obtained in electrolysis of (CH3)3N·5.0HF + 50 wt.% CsF·2.3HF mixed melt at 20 mA cm−2 and its value was 52.11%.
Electrochemical Double-Layer Structure of Pt Electrode/Ionic Liquids Interface Studied by in situ IR-visible Sum Frequency Generation Spectroscopy
Authors: Zhou Wei , Inoue Souya , Iwahashi T. , Kanai K. , Seki K. , Miyamae T. , Kim D. , Katayama Y. , Ouchi Y.
Published: August 2009

The electrochemical interface between a polycrystalline Pt electrode and an ionic liquid 1-butyl-3-methylimidazolium trifluoromethane sulfonate ([bmim]OTf) has been studied by in situ sum frequency generation (SFG) spectroscopy. Potential dependent adsorption and desorption processes of OTf anion as well as [bmim] cation have been observed. A double-layer model of the interface structure has been suggested based on the behavior of both the anion and the cation in the electrochemical potential window. Hysteresis effect has been observed during the desorption and the re-adsorption processes of both the anion and the cation on the Pt surface.
Electrochemical Behavior of Vanadium Oxides in Chloride-Fluoride Melts
Authors: Devyatkin Sergei
Published: August 2009

The determination of the oxidation state in which vanadium is in metallurgical slag's is an important factor in choosing the optimal conditions for the production of ferrovanadium by the silicothermal method. On the basis of thermodynamic calculations, electrochemical investigations and UV-Vis spectroscopy it has been shown that in vanadium-contain metallurgical slag's vanadium is in the form of V2O3.
Electrode Kinetics of Ferrocenium/ferrocene in Room-temperature Ionic Liquids
Authors: Tachikawa Naoki , Katayama Y. , Miura Takashi
Published: August 2009

The diffusion coefficients and heterogeneous rate constants of ferrocenium/ferrocene ([Fe(Cp)2]+/Fe(Cp)2) were investigated in order to elucidate the role of solvent dynamics on the electrode kinetics in hydrophobic room-temperature ionic liquids based on bis(trifluoromethylsulfonyl)imide (TFSI-). The [Fe(Cp)2]+/Fe(Cp)2 redox reaction was reversible from cyclic voltammetry of a platinum electrode. The diffusion coefficient of Fe(Cp)2 was inversely proportional to the viscosity of the ionic liquid. The diffusion coefficients of [Fe(Cp)2]+ in the ionic liquids were smaller than those of Fe(Cp)2 because of the Coulombic interaction between charged species and the ionic liquids. The apparent heterogeneous rate constants of [Fe(Cp)2]+/Fe(Cp)2 estimated by the electrochemical impedance spectroscopy in the ionic liquids were smaller than those in organic solvents. The heterogeneous rate constants correlate with the viscosity of the electrolytes probably due to the slow dynamics of the ions composing the ionic liquids.
Passivity Breakdown and Repassivation on TiNi During Rapid Straining Accompanying Martensitic Phase Transformation
Authors: Fujimoto Shinji , Yamamoto Hiroyuki
Published: August 2009

Passive film breakdown and repassivation during rapid deformation of Ni-Ti shape memory alloy were electrochemically characterized using a rapid straining electrode technique. A ribbon shape tensile specimen of Ni-50.1Ti alloy was elongated under potentio-static condition in simulated body fluid. Deformation induced mechanical breakdown of surface film to expose newly created surface resulting in a rapid transient of electrochemical current. Namely, anodic current increased, then decreased due to repassivation. Slight current increase during elastic elongation was followed by a rapid increase in current during martensitic deformation, which may induce surface nanoscopic protrusion and collapse, rapid increase in anodic current was observed. It is noticeable that rapid shrinking by reverse martensitic transformation also arose current increase due to surface film breakdown.
Critical Factors for Controlling the Stability of the Passive Film on Stainless Steels
Authors: Shibata Toshio
Published: August 2009

In order to understand the stable passivity of stainless steels, the critical factors including the mechanism of reductive dissolution relating to breakdown and repair of passive film have been reviewed based on recent evidence. The Cr enrichment in the passive film by two stage process and alloying effect are discussed in detail. The importance of the relationship between critical passivation current density, icrit, in acidic solution and pitting potential, Epit, in chloride solution is emphasized for understanding the stability of passive stainless steel.
Differential efficacy of SSTR1, -2, and -5 agonists in the inhibition of C6 glioma growth in nude mice
Authors: Barbieri Federica , Pattarozzi Alessandra , Gatti Monica , Aiello Cinzia , Quintero Ana , Lunardi Gianluigi , Bajetto Adriana , Ferrari Angelo , Culler Michael D. , Florio Tullio
Published: August 2009

Somatostatin receptors (SSTR1–5) mediate antiproliferative effects. In C6 rat glioma cells, somatostatin is cytostatic in vitro via phosphotyrosine phosphatase-dependent inhibition of ERK1/2 activity mediated by SSTR1, -2, and -5. Here we analyzed the effects of SSTR activation on C6 glioma growth in vivo and the intracellular mechanisms involved, comparing somatostatin effects with selective agonists for SSTR1, -2, and -5 (BIM-23745, BIM-23120, BIM-23206) or receptor biselective compounds (SSTR1 and -2, BIM-23704; and SSTR2 and -5, BIM-23190). Nude mice subcutaneously xenografted with C6 cells were treated with somatostatin, SSTR agonists (50 μg, twice/day), or vehicle. Tumor growth was evaluated every 3 days for 19 days. The intracellular pathways responsible of SSTR effects in vivo were evaluated measuring Ki-67, phospho-ERK1/2, and p27kip1 expression by immunohistochemistry in sections from explanted tumors. Somatostatin and SSTR1, -2, and -5 agonists strongly inhibited in vivo C6 tumor growth, intratumoral neovessel formation, Ki-67 expression, and ERK1/2 phosphorylation and induced upregulation of p27Kip1, whereas only a modest activation of caspase-3 was observed. Somatostatin (acting on SSTR1, -2, and -5) displayed the highest efficacy; SSTR5 selective agonist showed a stronger effect than SSTR1 agonist, and SSTR2 agonist was less effective. On the other hand, SSTR1 and -2 agonists maximally reduced tumor neovascularization. The combined activation of SSTR1 and -2 showed a synergistic activity, reaching a higher efficacy than BIM-23206, whereas the simultaneous activation of SSTR2 and -5 resulted in a response resembling SSTR5 effects. Thus the simultaneous activation of different SSTRs inhibits glioma cell proliferation in vivo through both direct cytotostatic and antiangiogenic effects.
Impact of type 1 diabetes on cardiac fibroblast activation: enhanced cell cycle progression and reduced myofibroblast content in diabetic myocardium
Authors: Shamhart Patricia E. , Luther Daniel J. , Hodson Ben R. , Koshy John C. , Ohanyan Vahagn , Meszaros J. Gary
Published: August 2009

Diabetic patients are prone to developing myocardial fibrosis and suffer from decreased wound healing capabilities. The purpose of this study was to determine whether diabetes alters cardiac fibroblast activity in the myocardium in a 6-wk streptozotocin-induced type 1 diabetic model. In vivo echocardiography indicated significant dilation of the left ventricle (LV) in the diabetic animals, while cardiac function was comparable to that in the normal group. We isolated cardiac fibroblasts from diabetic and control hearts and observed increased proliferation of the diabetic fibroblasts. Microarray analysis using mRNA collected from whole LVs revealed downregulation of known inhibitors of proliferation, p53 and p21, in the diabetic group, consistent with our proliferation data. Western blot analysis confirmed a reduction in p53 protein expression in the diabetic hearts compared with control. We explored the potential signaling underlying the downregulation of these cell cycle mediators and determined that activated Akt, a signal that inhibits p53, was elevated in the diabetic group. Surprisingly, the hearts from the diabetic group contained lower levels of the myofibroblast marker α-smooth muscle actin (α-SMA) and higher levels of desmin and platelet endothelial cell adhesion molecule (PECAM). The isolated fibroblasts from the diabetic group also contained significantly less α-SMA. These data suggest that early-stage diabetic hearts contain highly proliferative fibroblasts, which predisposes the diabetic myocardium to fibrosis, but have fewer myofibroblasts, which may compromise wound healing.
Activation of a novel estrogen receptor, GPER, is cardioprotective in male and female rats
Authors: Deschamps Anne M. , Murphy Elizabeth
Published: August 2009

Premenopausal females have a lower incidence of cardiovascular disease than their male counterparts, but the mechanism is unclear. Estrogen has been thought to signal through two nuclear receptors: estrogen receptor-α or estrogen receptor-β; however, a third, membrane-bound receptor G protein-coupled estrogen receptor (GPER), has been identified and shown to bind estrogen with high affinity. To date, there is little information on GPER in the heart and no study has looked at the effect of GPER activation during myocardial ischemia-reperfusion (I/R). Therefore, the goal of this study was to determine whether activation of GPER is cardioprotective in rats. A highly specific GPER agonist, G-1, was administered to Sprague-Dawley (200–350 g) rat hearts 10 min before 20 min of ischemic followed by 120 min of reperfusion using a Langendorff model. Similar levels of GPER were found in both male and female rat hearts. With administration of 110 nM of G-1, postischemic contractile dysfunction was significantly reduced compared with untreated controls (43.8 ± 4.3% vs. 26.9 ± 2.1% of preischemic rate pressure product; P < 0.05). Additionally, infarct size was reduced in the G-1-treated animals when compared with control (18.8 ± 2.7% vs. 32.4 ± 2.1%; P < 0.05). These observations were demonstrated in both male and intact female rat hearts. Through Western blot analysis, it was demonstrated that G-1 induces the activation of both Akt and ERK1/2. Furthermore, the protection afforded by G-1 was blocked by coadministration of a phosphatidylinositol 3-kinase (PI3K) inhibitor (wortmannin, 100 nM). Taken together, the data show that G-1 activation of GPER improves functional recovery and reduces infarct size in isolated rat hearts following I/R through a PI3K-dependent, gender-independent mechanism.
Role of tetrahydrobiopterin in resistance to myocardial ischemia in Brown Norway and Dahl S rats
Authors: An Jianzhong , Du Jianhai , Wei Na , Xu Hao , Pritchard Kirkwood A. , Shi Yang
Published: August 2009

Previously we showed that Brown Norway (BN/Mcw) rats are more resistant to myocardial ischemia-reperfusion (I/R) injury than Dahl S (SS/Mcw) rats due to increased nitric oxide (·NO) generation secondary to increased heat shock protein 90 (HSP90) association with endothelial nitric oxide synthase (NOS3). Here we determined whether increased resistance to I/R injury in BN/Mcw hearts is also related to tetrahydrobiopterin (BH4) and GTP cyclohydrolase I (GCH-1), the rate-limiting enzyme for BH4synthesis. We observed that BH4supplementation via sepiapterin (SP) and inhibition of GCH-1 via 2,4-diamino-6-hydroxypyrimidine (DAHP) differentially modulate cardioprotection and that SP alters the association of HSP90 with NOS3. BH4levels were significantly higher and 7,8-dihydrobiopterin (BH2) levels were significantly lower in BN/Mcw than in SS/Mcw hearts. The BH4-to-BH2ratio in BN/Mcw was more than two times that in SS/Mcw hearts. After I/R, BH4decreased and BH2increased in hearts from both strains compared with their preischemia levels. However, the increase in BH2in SS/Mcw hearts was significantly higher than in BN/Mcw hearts. Real-time PCR revealed that BN/Mcw hearts contained more GCH-1 transcripts than SS/Mcw hearts. SP increased recovery of left ventricular developed pressure (rLVDP) following I/R as well as decreased superoxide (O2•−) and increased·NO in SS/Mcw hearts but not in BN/Mcw hearts. DAHP decreased rLVDP as well as increased O2•−and decreased·NO in BN/Mcw hearts compared with controls but not in SS/Mcw hearts. SP increased the association of HSP90 with NOS3. These data indicate that BH4mediates resistance to I/R by acting as a cofactor and enhancing HSP90-NOS3 association.
Inhibition of geranylgeranyltransferase inhibits bronchial smooth muscle hyperresponsiveness in mice
Authors: Chiba Yoshihiko , Sato Shunsuke , Hanazaki Motohiko , Sakai Hiroyasu , Misawa Miwa
Published: August 2009

Recent studies revealed an involvement of RhoA/Rho-kinase in the contraction of bronchial smooth muscle (BSM), and this pathway has now been proposed as a new target for asthma therapy. A posttranslational geranylgeranylation of RhoA is required for its activation. Thus selective inhibition of geranylgeranyltransferase may be a novel strategy for treatment of the BSM hyperresponsiveness in asthmatics. To test this hypothesis, we investigated the effect of a geranylgeranyltransferase inhibitor, GGTI-2133, on antigen-induced BSM hyperresponsiveness by using mice with experimental asthma. Mice were sensitized and repeatedly challenged with ovalbumin antigen. Animals also were treated with GGTI-2133 (5 mg/kg ip) once a day before and during the antigen inhalation period. Repeated antigen inhalation caused a BSM hyperresponsiveness to acetylcholine with the increased expressions of RhoA and the anti-farnesyl-positive 21-kDa proteins, probably geranylgeranylated RhoA. The in vivo GGTI-2133 treatments significantly inhibited BSM hyperresponsiveness induced by antigen exposure. In another series of experiments, BSM tissues isolated from the repeatedly antigen-challenged mice were cultured for 48 h in the absence or presence of GGTI-2133. Under these conditions, the putative geranylgeranylated RhoA was decreased in a GGTI-2133 concentration-dependent manner. The in vitro incubation with GGTI-2133 also inhibited BSM hyperresponsiveness induced by antigen exposure. These findings suggest that GGTI-2133 inhibits antigen-induced BSM hyperresponsiveness, probably by reducing downstream signal transduction of RhoA. Selective geranylgeranyltransferase inhibitors may be beneficial for the treatment of airway hyperresponsiveness, one of the characteristic features of allergic bronchial asthma.
Area Summation in Human Visual System: Psychophysics, fMRI, and Modeling
Authors: Nurminen Lauri , Kilpeläinen Markku , Laurinen Pentti , Vanni Simo
Published: August 2009

Contextual modulation is a fundamental feature of sensory processing, both on perceptual and on single-neuron level. When the diameter of a visual stimulus is increased, the firing rate of a cell typically first increases (summation field) and then decreases (surround field). Such an area summation function draws a comprehensive profile of the receptive field structure of a neuron, including areas outside the classical receptive field. We investigated area summation in human vision with psychophysics and functional magnetic resonance imaging (fMRI). The stimuli were similar to those used drifting sine wave gratings in previous macaque single-cell area summation studies. A model was developed to facilitate comparison of area summation in fMRI to area summation in psychophysics and single cells. The model consisted of units with an antagonistic receptive field structure found in single cells in the primary visual cortex. The receptive field centers of the model neurons were distributed in the region of the visual field covered by a single voxel. The measured area summation functions were qualitatively similar to earlier single-cell data. The model with parameters derived from psychophysics captured the spatial structure of the summation field in the primary visual cortex as measured with fMRI. The model also generalized to a novel situation in which the neural population was displaced from the stimulus center. The current study shows that contextual modulation arises from similar spatially antagonistic and overlapping excitatory and inhibitory mechanisms, both in single cells and in human vision.
Exploring the Superior Colliculus In Vitro
Authors: Isa Tadashi , Hall William C.
Published: August 2009

The superior colliculus plays an important role in the translation of sensory signals that encode the location of objects in space into motor signals that encode vectors of the shifts in gaze direction called saccades. Since the late 1990s, our two laboratories have been applying whole cell patch-clamp techniques to in vitro slice preparations of rodent superior colliculus to analyze the structure and function of its circuitry at the cellular level. This review describes the results of these experiments and discusses their contributions to our understanding of the mechanisms responsible for sensorimotor integration in the superior colliculus. The experiments analyze vertical interactions between its superficial visuosensory and intermediate premotor layers and propose how they might contribute to express saccades and to saccadic suppression. They also compare and contrast the circuitry within each of these layers and propose how this circuitry might contribute to the selection of the targets for saccades and to the build-up of the premotor commands that precede saccades. Experiments also explore in vitro the roles of extrinsic inputs to the superior colliculus, including cholinergic inputs from the parabigeminal and parabrachial nuclei and GABAergic inputs from the substantia nigra pars reticulata, in modulating the activity of the collicular circuitry. The results extend and clarify our understanding of the multiple roles the superior colliculus plays in sensorimotor integration.
Gene expression and muscle fiber function in a porcine ICU model
Authors: Banduseela Varuna C. , Ochala Julien , Chen Yi-Wen , Göransson Hanna , Norman Holly , Radell Peter , Eriksson Lars I. , Hoffman Eric P. , Larsson Lars
Published: August 2009

Skeletal muscle wasting and impaired muscle function in response to mechanical ventilation and immobilization in intensive care unit (ICU) patients are clinically challenging partly due to 1) the poorly understood intricate cellular and molecular networks and 2) the unavailability of an animal model mimicking this condition. By employing a unique porcine model mimicking the conditions in the ICU with long-term mechanical ventilation and immobilization, we have analyzed the expression profile of skeletal muscle biopsies taken at three time points during a 5-day period. Among the differentially regulated transcripts, extracellular matrix, energy metabolism, sarcomeric and LIM protein mRNA levels were downregulated, while ubiquitin proteasome system, cathepsins, oxidative stress responsive genes and heat shock proteins (HSP) mRNAs were upregulated. Despite 5 days of immobilization and mechanical ventilation single muscle fiber cross-sectional areas as well as the maximum force generating capacity at the single muscle fiber level were preserved. It is proposed that HSP induction in skeletal muscle is an inherent, primary, but temporary protective mechanism against protein degradation. To our knowledge, this is the first study that isolates the effect of immobilization and mechanical ventilation in an ICU condition from various other cofactors.
Transcription profiling and regulation of fat metabolism genes in diapausing adults of the mosquito Culex pipiens
Authors: Sim Cheolho , Denlinger David L.
Published: August 2009

Culex pipiens , the mosquito that vectors West Nile virus in North America, overwinters in an adult diapause (dormancy) that is programmed by the short day length and low temperatures of autumn. In response to these environmental signals, females cease feeding on blood and instead seek sources of nectar used to generate the huge lipid reserves required for winter survival. To identify regulatory networks that regulate fat accumulation and fat consumption during diapause, we compared expression of fat-related genes from nondiapausing females with expression of those same genes in early and late diapause and at diapause termination. Among the 31 genes we examined, 4 were expressed more highly in early diapause than in nondiapause, while 14 genes were downregulated in early diapause. In the transition from early to late diapause, 19 genes related to fat metabolism were upregulated. As reported previously, fatty acid synthase, identified as fas-1 in this study, was upregulated in early diapause. Numerous fat metabolism genes, including multiple kinetic classes and genes involved in β-oxidation, an energy-generation step, were suppressed in early diapause but were highly expressed in late diapause and at diapause termination. RNA interference (RNAi) analysis revealed that the fas-1 gene and others ( fas-3 and fabp) have important roles in fat storage during early diapause. When expression of these genes is suppressed, female mosquitoes fail to sequester the lipids needed for overwintering.
Synthesis, crystal structure and vibrational spectra of Sr0.5Zr2(AsO4)3
Authors: Jrifi A. , El Jazouli A. , Chaminade J. P. , Couzi M.
Published: August 2009

Sr0.5Zr2(AsO4)3 arsenate was prepared and structurally characterized by powder X-ray diffraction and by Raman and infrared spectroscopies. Its structure, which belongs to the Nasicon-type family, was refined by the Rietveld method in the R-3 space group, from X-ray powder diffraction data. The hexagonal unit-cell parameters were determined to be ah=8.965(2) Å, ch=23.955(6) Å, V=1667.43(6) Å3, and Z=6. The structure is formed by an ionic three-dimensional network of AsO4 tetrahedra and ZrO6 octahedra linked by corners with Sr2+ ions occupying half of the M1 sites in an ordered manner. Raman and infrared spectra were recorded and assignments of the stretching and bending vibrations of the AsO43− tetrahedra were made. The number of the peaks observed is in good agreement with that predicted by the factor-group analysis of the R-3 space group.
New diffraction data and crystal structure of HoCo0.67Ga1.33
Authors: Yan Jialin , Liang Liuqing , Lu Xingwen , Zeng Lingmin , Nong Liangqin
Published: August 2009

Compound HoCo0.67Ga1.33 was synthesized and studied by means of X-ray powder diffraction technique. HoCo0.67Ga1.33 was found to have the orthorhombic CeCu2 structure (space group Imma) with a=4.3479(2) Å, b=7.0351(3) Å, c=7.4876(3) Å, Z=4, and Dcalc=8.62 g/cm3. The crystal structure of HoCo0.67Ga1.33 was also refined by the Rietveld method. Ho atoms were found to occupy the 4e positions and mixed Co/Ga atoms to share the 8h positions of the space group Imma (No. 74).
New statistical calibration approach for Bruker AXS D8 Discover microdiffractometer with Hi-Star detector using GADDS software
Authors: Rowe Ralph
Published: August 2009

An additional statistical calibration for the Bruker D8 Discover microdiffractometer is necessary to obtain accurate reproducible 2θ data for cell-refinement work. This new approach uses a graphical mapping method of the 2θ error versus the location of a selected diffraction peak on the detector surface to describe the separate roles of different calibration procedures (rebiasing, flood field, and spatial corrections) and parameters (sample-to-detector distance, x-y center coordinate) in minimizing the error. Optimized parameters are used to obtain the lowest achievable Δ2θ with this setup. Intensity error relative to the position of the diffracted line on the detector was found to be consistent at up to 20% and could not be reduced using any of the investigated techniques and parameters.
Multiple Description Coding Using Data Hiding and Regions of Interest for Broadcasting Applications
Authors: Verza M. , Conci N. , Boato G. , De Natale F. G. B.
Published: August 2009

We propose an innovative scheme for multiple description coding (MDC) with regions of interest (ROI) support to be adopted in high-quality television. The scheme proposes to split the stream into two separate descriptors and to preserve the quality of the region of interest, even in case one descriptor is completely lost. The residual part of the frame (the background) is instead modeled through a checkerboard pattern, alternating the strength of the quantization. The decoder is provided with the necessary side-information to reconstruct the frame properly, namely, the ROI parameters and location, via a suitable data hiding procedure. Using data hiding, reconstruction parameters are embedded in the transform coefficients, thus allowing an improvement in PSNR of the single descriptions at the cost of a negligible overhead. To demonstrate its effectiveness, the algorithm has been implemented in two different scenarios, using the reference H.264/AVC codec and an MJPEG framework to evaluate the performance in absence of motion-compensated frames on 720p video sequences.
Experimental Measurements of Host Identity Protocol for Mobile Nodes′ Networks
Authors: Ben Jemaa Maher , Abid Nahla , Laurent-Maknavicius Maryline , Chaouchi Hakima
Published: August 2009

The role of Internet Protocol (IP) is becoming more and more problematic especially with the new requirements of mobility and multihoming. Host Identity protocol (HIP) defines a new protocol between the network and transport layers in order to provide a better management to those requirements. The protocol defines a new namespace based on cryptographic identifiers which enable the IP address roles dissociation. Those new identifiers identify hosts rather than IP addresses. Because HIP is a quite recent protocol, we propose to present an experimental evaluation of its basic characteristics.
The Severity of Autism Is Associated with Toxic Metal Body Burden and Red Blood Cell Glutathione Levels
Authors: Adams J. B. , Baral M. , Geis E. , Mitchell J. , Ingram J. , Hensley A. , Zappia I. , Newmark S. , Gehn E. , Rubin R. A. , Mitchell K. , Bradstreet J. , El-Dahr J. M.
Published: August 2009

This study investigated the relationship of children's autism symptoms with their toxic metal body burden and red blood cell (RBC) glutathione levels. In children ages 3–8 years, the severity of autism was assessed using four tools: ADOS, PDD-BI, ATEC, and SAS. Toxic metal body burden was assessed by measuring urinary excretion of toxic metals, both before and after oral dimercaptosuccinic acid (DMSA). Multiple positive correlations were found between the severity of autism and the urinary excretion of toxic metals. Variations in the severity of autism measurements could be explained, in part, by regression analyses of urinary excretion of toxic metals before and after DMSA and the level of RBC glutathione (adjusted of 0.22–0.45, in all cases). This study demonstrates a significant positive association between the severity of autism and the relative body burden of toxic metals.
Cronkhite-Canada Syndrome: A Case Report and Review of Literature
Authors: Kao Kevin T. , Patel Jitesh K. , Pampati Vijayamalini
Published: August 2009

Cronkhite-Canada syndrome (CCS) is a rare syndrome first described in 1955. (1) Since then, 400 cases worldwide have been reported in the literature. The disease is characterized by diffuse gastrointestinal polyposis, dystrophic changes of the fingernails, alopecia, cutaneous hyperpigmentation, diarrhea, weight loss, and abdominal pain. (2) The etiology is currently unknown, but an autoimmune process is suspected. The workup is based on history and physical followed by imaging and endoscopy with biopsy to confirm gastrointestinal polyposis. The goal of treatment focuses on symptomatic management of the patient and nutritional support.
Five-Year Long-Term Followup of a Primary Lymph node Gastrinoma: Is a Pancreaticoduodenectomy Justified?
Authors: Jaenigen Bernd , Kayser Gian , Steinke Berthold , Thomusch Oliver
Published: August 2009

Background. Gastrinoma-positive lymph nodes and failed localization of the primary tumor during surgical exploration are described. Specialists suppose that these lymph nodes are metastases rather than a primary gastrinoma.Methods. Case report with a five-year long-term followup. A 60-year-old patient with an confirmed gastrinoma was treated in our department. All preoperative evaluations including somatostatin-receptor-scintigraphy and F-Dopa PET failed to localize the gastrinoma. Explorative laparotomy revealed a gastrinoma in two peripancreatic lymph nodes. Despite extensive intraoperative exploration, no primary gastrinoma could be detected in typical localization.Results. Over a period of 5 years, the patient's gastrin level stayed in the normal range and the patient seems to be completely cured.Conclusion. A prophylactic partial pancreatoduodenectomy is not indicated to avoid recurrence, since complete biochemical cure by local resection of the lymph node gastrinoma is possible.
A Novel Splice Variant of GLI1 That Promotes Glioblastoma Cell Migration and Invasion
Authors: Lo Hui-Wen , Zhu Hu , Cao Xinyu , Aldrich Amy , Ali-Osman Francis
Published: August 2009

The family of GLI zinc finger transcription factors regulates the expression of genes involved in many important cellular processes, notably embryonal development and cellular differentiation. The glioma-associated oncogene homologue 1 (GLI1) isoform, in particular, has attracted much attention because of its frequent activation in many human cancers and its interactions with other signaling pathways, such as those mediated by K-RAS, transforming growth factor-β, epidermal growth factor receptor, and protein kinase A. Here, we report the identification of a novel truncated GLI1 splice variant, tGLI1, with an in-frame deletion of 123 bases (41 codons) spanning the entire exon 3 and part of exon 4 of the GLI1 gene. Expression of tGLI1 is undetectable in normal cells but is high in glioblastoma multiforme (GBM) and other cancer cells. Although tGLI1 undergoes nuclear translocalization and transactivates GLI1-binding sites similar to GLI1, unlike GLI1, it is associated with increased motility and invasiveness of GBM cells. Using microarray analysis, we showed >100 genes to be differentially expressed in tGLI1-expressing compared with GLI1-expressing GBM cells, although both cell types expressed equal levels of known GLI1-regulated genes, such as PTCH1. We further showed one of the tGLI1 up-regulated genes, CD24, an invasion-associated gene, to be required for the migratory and invasive phenotype of GBM cells. These data provide conclusive evidence for a novel gain-of-function GLI1 splice variant that promotes migration and invasiveness of GBM cells and open up a new research paradigm on the role of the GLI1 pathway in malignancy. [Cancer Res 2009;69(17):6790–8]
Human Papillomavirus 16 E7 Oncoprotein Attenuates DNA Damage Checkpoint Control by Increasing the Proteolytic Turnover of Claspin
Authors: Spardy Nicole , Covella Kathryn , Cha Elliot , Hoskins Elizabeth E. , Wells Susanne I. , Duensing Anette , Duensing Stefan
Published: August 2009

The human papillomavirus (HPV) 16 E7 oncoprotein has been reported previously to stimulate DNA damage and to activate host cell DNA damage checkpoints. How HPV-16 E7 maintains proliferation despite activated DNA damage checkpoints is incompletely understood. Here, we provide evidence that cells expressing the HPV-16 E7 oncoprotein can enter mitosis in the presence of DNA damage. We show that this activity of HPV-16 E7 involves attenuation of DNA damage checkpoint control by accelerating the proteolytic turnover of claspin. Claspin mediates the activation of CHK1 by ATR in response to replication stress, and its degradation plays a critical role in DNA damage checkpoint recovery. Expression of a nondegradable mutant of claspin was shown to inhibit mitotic entry in HPV-16 E7–expressing cells. Multiple components of the SCFβ-TrCP–based claspin degradation machinery were found deregulated in the presence of HPV-16 E7, including cullin 1, β-TrCP, Aurora A, and Polo-like kinase-1 (PLK1). In contrast, no difference in the expression level of the claspin deubiquitinating enzyme USP7 was detected. Levels of Aurora A and PLK1 as well as phosphorylated PLK1 at threonine 210, a prerequisite for DNA damage checkpoint recovery, remained detectable following replication stress in HPV-16 E7–expressing cells but not in control cells. In summary, our results suggest that the HPV-16 E7 oncoprotein alleviates DNA damage checkpoint responses and promotes mitotic entry by accelerating claspin degradation through a mechanism that involves deregulation of components of the SCFβ-TrCP–based claspin degradation machinery. [Cancer Res 2009;69(17):7022–9]
Adjuvant Hormonal Therapy for Breast Cancer and Risk of Hormone Receptor–Specific Subtypes of Contralateral Breast Cancer
Authors: Li Christopher I. , Daling Janet R. , Porter Peggy L. , Tang Mei-Tzu C. , Malone Kathleen E.
Published: August 2009

Compared with the breast cancer risk women in the general population have, breast cancer survivors have a substantially higher risk of developing a second primary contralateral breast cancer. Adjuvant hormonal therapy reduces this risk, but preliminary data indicate that it may also increase risk of hormone receptor–negative contralateral tumors. We conducted a population-based nested case-control study including 367 women diagnosed with both first primary estrogen receptor (ER)–positive invasive breast cancer and second primary contralateral breast cancer and 728 matched control women diagnosed only with a first breast cancer. Data on adjuvant hormonal therapy, other treatments, and breast cancer risk factors were ascertained through telephone interviews and medical record abstractions. Two-sided statistical tests using conditional logistic regression were conducted to quantify associations between adjuvant hormonal therapy and risk of hormone receptor–specific subtypes of contralateral breast cancer (n = 303 ER+ and n = 52 ER− cases). Compared with women not treated with hormonal therapy, users of adjuvant tamoxifen for ≥5 years had a reduced risk of ER+ contralateral breast cancer [odds ratio, 0.4; 95% confidence interval (CI), 0.3–0.7], but a 4.4-fold (95% CI, 1.03–19.0) increased risk of ER− contralateral breast cancer. Tamoxifen use for <5 years was not associated with ER− contralateral breast cancer risk. Although adjuvant hormonal therapy has clear benefits, risk of the relatively uncommon outcome of ER− contralateral breast cancer may now need to be tallied among its risks. This is of clinical concern given the poorer prognosis of ER− compared with ER+ tumors. [Cancer Res 2009;69(17):6865–70]
Multimodal Assessment of Protein Functional Deficiency Supports Pathogenicity of BRCA1 p.V1688del
Authors: De Nicolo Arcangela , Parisini Emilio , Zhong Quan , Dalla Palma Maurizia , Stoeckert Kathryn A. , Domchek Susan M. , Nathanson Katherine L. , Caligo Maria A. , Vidal Marc , Cusick Michael E. , Garber Judy E.
Published: August 2009

Unequivocal discrimination between neutral variants and deleterious mutations is crucial for appropriate counseling of individuals with a BRCA1 or BRCA2 sequence change. An increasing number of variants of uncertain significance (VUS) are being identified, the unclassified biological effect of which poses clinical concerns. A multifactorial likelihood–based approach recently suggested disease causality for BRCA1 p.V1688del, a VUS recurrent in Italian breast/ovarian cancer families. Whether and how this single amino acid deletion in the BRCA1 COOH terminus (BRCT) domain affects the function of the mutant protein (ΔValBRCA1) has not been elucidated. We undertook comprehensive functional characterization of ΔValBRCA1, comprising comparative structural modeling, analysis of protein stability and associations, and analysis of DNA repair function. Our model predicted BRCT domain destabilization and folding disruption caused by BRCA1 p.V1688del. Consistently, the recombinant ΔValBRCA1 was less stable than wild-type BRCA1 and, unlike the latter, failed to associate with BRIP1, CtIP, and Rap80 and to relocalize to sites of DNA damage. Yeast two-hybrid analysis revealed a compromised interaction with FHL2 and KPNA2, which is likely responsible for improper subcellular localization of ΔValBRCA1. In addition, we found four new breast/ovarian cancer families of Italian ancestry who carried this sequence alteration. These results provide the first evidence of the effect of BRCA1 p.V1688del on protein stability and function, supporting the view that it is a deleterious mutation. Multimodal analyses like ours could advance understanding of tumor suppression by BRCA1 and ultimately contribute to developing efficient strategies for screening and characterization of VUS. [Cancer Res 2009;69(17):7030–7]
Preclinical Evaluation of Novel Glutamate-Urea-Lysine Analogues That Target Prostate-Specific Membrane Antigen as Molecular Imaging Pharmaceuticals for Prostate Cancer
Authors: Hillier Shawn M. , Maresca Kevin P. , Femia Frank J. , Marquis John C. , Foss Catherine A. , Nguyen Nghi , Zimmerman Craig N. , Barrett John A. , Eckelman William C. , Pomper Martin G. , Joyal John L. , Babich John W.
Published: August 2009

Prostate-specific membrane antigen (PSMA) is expressed in normal human prostate epithelium and is highly up-regulated in prostate cancer. We previously reported a series of novel small molecule inhibitors targeting PSMA. Two compounds, MIP-1072, (S)-2-(3-((S)-1-carboxy-5-(4-iodobenzylamino)pentyl)ureido)pentanedioic acid, and MIP-1095, (S)-2-(3-((S)-1carboxy-5-(3-(4-iodophenyl)ureido)pentyl)ureido)pentanedioic acid, were selected for further evaluation. MIP-1072 and MIP-1095 potently inhibited the glutamate carboxypeptidase activity of PSMA (Ki = 4.6 ± 1.6 nmol/L and 0.24 ± 0.14 nmol/L, respectively) and, when radiolabeled with 123I, exhibited high affinity for PSMA on human prostate cancer LNCaP cells (Kd = 3.8 ± 1.3 nmol/L and 0.81 ± 0.39 nmol/L, respectively). The association of [123I]MIP-1072 and [123I]MIP-1095 with PSMA was specific; there was no binding to human prostate cancer PC3 cells, which lack PSMA, and binding was abolished by coincubation with a structurally unrelated NAALADase inhibitor, 2-(phosphonomethyl)pentanedioic acid (PMPA). [123I]MIP-1072 and [123I]MIP-1095 internalized into LNCaP cells at 37°C. Tissue distribution studies in mice showed 17.3 ± 6.3% (at 1 hour) and 34.3 ± 12.7% (at 4 hours) injected dose per gram of LNCaP xenograft tissue, for [123I]MIP-1072 and [123I]MIP-1095, respectively. [123I]MIP-1095 exhibited greater tumor uptake but slower washout from blood and nontarget tissues compared with [123I]MIP-1072. Specific binding to PSMA in vivo was shown by competition with PMPA in LNCaP xenografts, and the absence of uptake in PC3 xenografts. The uptake of [123I]MIP-1072 and [123I]MIP-1095 in tumor-bearing mice was corroborated by single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. PSMA-specific radiopharmaceuticals should provide a novel molecular targeting option for the detection and staging of prostate cancer. [Cancer Res 2009;69(17):6932–40]
2009 Biospecimen Research Network Symposium: Advancing Cancer Research through Biospecimen Science
Authors: Moore Helen M. , Compton Carolyn C. , Lim Mark D. , Vaught Jimmie , Christiansen Katerina N. , Alper Joe
Published: August 2009

This report details the proceedings of the 2009 Biospecimen Research Network (BRN) Symposium that took place on March 16 to 18, 2009, the second in a series of annual symposia sponsored by the National Cancer Institute Office of Biorepositories and Biospecimen Research. The BRN Symposium is a public forum addressing the relevance of biospecimen quality to progress in cancer research and the systematic investigation needed to understand how different methods of collection, processing, and storage of human biospecimens affect subsequent molecular research results. More than 300 participants from industry, academia, and government attended the symposium, which featured both formal presentations and a day of workshops aimed at addressing several key issues in biospecimen science. An additional 100 individuals participated via a live webcast (archived at http://brnsymposium.com). The BRN Symposium is part of a larger program designed as a networked, multidisciplinary research approach to increase the knowledge base for biospecimen science. Biospecimens are generally understood to represent an accurate representation of a patient's disease biology, but can instead reflect a combination of disease biology and the biospecimen's response to a wide range of biological stresses. The molecular signatures of disease can thus be confounded by the signatures of biospecimen biological stress, with the potential to affect clinical and research outcomes through incorrect diagnosis of disease, improper use of a given therapy, and irreproducible research results that can lead to misinterpretation of artifacts as biomarkers. Biospecimen research represents the kind of bricks-and-mortar research that provides a solid scientific foundation for future advances that will directly help patients. [Cancer Res 2009;69(17):6770–2]