bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and Optical Properties on ZnO-based Alloys
Authors: Collins John , Shimizu Steven , Tao J. , Grasetti Jeffrey , McKittrick Joanna , Talbot J. , Tauber Michael , Mishra K. C. , Hamby David , Di Bartolo Baldassare
Published: March 2009

In this work we report on structural and optical properties of ZnO-MgO alloys. The alloys were synthesized using the combustion and co-precipitation methods, forming solid solutions of ZnO powders with MgO. SEM measurements show that the powders have sizes on the order of tens of nanometers, and XRD measurements indicate that the compounds produced are solid solutions of MgO in the ZnO lattice. The bandgaps of these solid solutions, as determined from reflectance measurements, increase with increasing MgO concentration. The luminescence measurements show emission from the bound exciton and from defects in the lattice. The excitonic emission shifts to higher energies as the MgO concentration increases.
Cathodoluminescence and Photoluminescence from Tb3+ in GaN Powder and Thin Films
Authors: Laski J. , Tao J. , Mishra K. C. , Hamby David , Raukas Madis , Klinedinst K. , McKittrick Joanna , Talbot J. , Perea-Lopez Nestor , Hirata Gustavo
Published: March 2009

We report luminescence from intra-configurational f-f transitions of Tb3+ in GaN powders and thin films deposited on sapphire substrates using metal organic vapor phase epitaxy (MOVPE) and pulsed laser deposition (PLD). The MOVPE film was grown using the precursor tris(2,2,6,6-tetramethyl-3,5-heptanedionato)terbium, while the PLD films were prepared from powder samples of GaN:Tb3+ prepared by a solution approach. All films yielded transitions of Tb3+ originating from the 5D4 state of Tb3+ to the 7F5 level as well as near bandgap emission (NBE) under cathodoluminescence (CL) excitation. The same transitions were also observed in the source powder of the PLD films, with the exceptions of the NBE at 370 nm. This indicates that the films contain lower defect level than the powders, which improves the quality of the material.
Electrodeposited Cu-In-Ga-Se Precursor Layers
Authors: Bhattacharya Raghu N. , Zhao Wenjun , Phok Sovannary
Published: March 2009

Cu-In-Se (CIS) and Cu-In-Ga-Se (CIGS) thin films have been prepared by the electrodeposition technique on molybdenum-coated glass substrates. In this process, electrodeposited precursor films are prepared at varying deposition bath temperatures, deposition currents, electrolyte concentrations, and deposition times. The films are annealed at about 550ºC in Se for 15 minutes and also by rapid thermal processing in flowing argon gas. The as-deposited and annealed films are characterized by inductively coupled plasma spectrometry and x-ray diffraction analysis.
Electrorecovery of Actinides at Room Temperature
Authors: Stoll Michael , Oldham Warren , Costa David
Published: March 2009

The electrochemical behavior of U(IV) and U(III) species in room temperature ionic liquids (RTILs) and the relatively low vapor pressure solvents NMP and DMSO is described. These studies have been ongoing in our laboratory to uncover conditions that will lead to the successful bulk electrodeposition of actinide metals at a working electrode surface at room temperature or slightly elevated temperatures. The RTILs we have focused on thus far are based on 1,3-dialkylimidazolium or quaternary ammonium cations and -N(SO2CF3)2 anions. Our results from XPS studies of electrooxidized uranium metal surfaces indicate that uranium metal reacts with the anion from the RTIL, most likely through an initial fluoride abstraction, forming decomposition products that inhibit the bulk electrodeposition of uranium metal. Similar results were found when the organic solvents were used with TBA[B(C6F5)4] as the supporting electrolyte, although the voltammetric data of uranium ions in these solutions is more encouraging in relation to electrodeposition of uranium metal. Preliminary results on the voltammetric behavior and bulk electrodeposition of plutonium species are also presented.
A Novel Fabrication of Cu-Mn Alloy Films by Chemical Displacement Process
Authors: Lin Li-Min , Yang Wen-Luh , Dai Ming-Jie , Yang Tsong-Jen , Yang Chin-Hao , Huang Fang T. , Wang Chin-An , Huang Shin-Yi
Published: March 2009

The Cu-Mn alloy films have been successfully fabricated by a novel chemical displacement process. The surface morphologies and displacement rate of Cu-Mn with pH values and temperatures are investigated in this paper. Furthermore, this chemical displacement is a selective deposition between Si and SiO2, this predominance can apply to self-formed metal layer. The chemical displacement process provides a solution to satisfy for 32 nm node Cu-Mn alloy self-formed barrier requirement.
High Rate Etching of Ru and TaN using Electrochemical Reaction for Bevel Cleaning
Authors: Aoki Hidemitsu , Watanabe Daisuke , Ooi Naoki , Jeong Jong-Hyeon , Kimura Chiharu , Sugino Takashi
Published: March 2009

We have developed a new wet technology using electrochemical etching for removing Ru (ruthenium) film and TaN (tantalum nitride) film on the wafer bevels for Back End of Line (BEOL) processes of system LSIs. The etching rates of 50nm/min and 25nm/min for Ru film and TaN film are achieved by diluted HCl solution of 0.5%, respectively. This process can provide a stable, low cost and environmentally friendly process without conventional special and conc. solutions.
Synthesis and Electrochemical Properties of Porous Carbon Composites Coated with Manganese Oxide Nanosheets
Authors: Kagei Yuta , Suzuki Shinya , Miyayama Masaru
Published: March 2009

Porous carbon composites coated with manganese oxide nanosheets were synthesized aimed at accomplishing the microstructural controls to enhance a high-rate capability. On the synthesis of the composites, alternative coatings with positively-charged polyethyleneimine and negatively-charged manganese oxide nanosheets onto porous carbon were performed. A composite with 55 wt% of MnO2 contents showed discharge capacities of 133 mAh/(g-MnO2) at a low discharge current density of 50 mA/(g-MnO2) and 63 mAh/(g-MnO2) at a high current density of 2000 mA/(g-MnO2). This rate capability is adequately good as an electrode for the highrate capable Li-ion batteries.
Deterioration Analysis of DC internal resistance by "Current-Rest-Method" using the "Four-Electrode Cell" for LIB
Authors: Yata Shizukuni , Kinoshita Hajime , Satake Hisashi , Kinoshita Shunji
Published: March 2009

After 500 hours of the floating test, the C.R.M. resistance of the cell at around 3.6 V in the discharge process doubled from 23.1 Ω to 39.6 Ω. We investigated what caused the increase in the resistance by separating the C.R.M. resistance of the cell using the "four-electrode cell". At the sixth current-rest point in the discharge process, the C.R.M. resistance of the positive electrode increased by 16.3 Ω, while that of the negative electrode increased by only 1.3 Ω. The "ohmic component" in the C.R.M. resistance of the positive electrode remarkably increased in the low voltage region compared to that of the negative electrode. The separation of resistance using the "four-electrode cell" allows us to clarify deterioration factors in cells easily.
Imaging and Modeling for Engineering the Li-ion Battery Electrode
Authors: Stux Arnold M. , Gorzkowski Ed , Rowenhorst David , Stephenson David , Wheeler Dean R.
Published: March 2009

Li-ion battery electrodes are ion-milled and prepared for three-dimensional reconstruction imaging using a focused ion beam and a method of automated serial sectioning. This tool is being developed as a means to gain additional information not typically obtained with traditional microscopy in order to improve models and further understand the structure-performance relationships. Images of the morphology acquired in such a way can be entered in a mathematical model which describes the underlying processes and physical, chemical, and electrical phenomena. Modifications to the electrode fabrication process can be made to achieve the desired morphology. This three-pronged approach provides an opportunity to develop more rigorous models and allows some predictive ability in performance of a new material or electrode film.
Efficient Reformulation of Solid-Phase Diffusion in Physics-Based Lithium-ion Battery Models
Authors: Ramadesigan Venkatasailanathan , Boovaragavan Vijayasekaran , Subramanian V. R.
Published: March 2009

One of the major difficulties in simulating the Li-ion battery models is the inclusion of solid phase diffusion in a second dimension in r. It increases the complexity of the model as well as the computation time/cost to a great extent. Rigorous approach towards solid phase diffusion leads to more difficulties, with the use of emerging cathode materials which involve phase changes and thus moving boundaries. This paper compares approaches available today for solid phase reformulation and provides two most efficient forms for constant and varying diffusivities in the solid phase.
Li2S-P2S5 Based Solid State Electrolytes for Lithium Ion Battery Applications
Authors: Trevey James E. , Jung Yoon S. , Lee Se-Hee
Published: March 2009

Sulfide-based Li2S-P2S5 solid state electrolytes were prepared by a high energy ball milling process. Characterization of the xLi2S-(100-x)P2S5] system for 70<x<80 was carried out for both amorphous glass and crystalline glass-ceramic materials by X-ray diffraction and electrochemical methods. Both glass and glass-ceramic electrolytes exhibited high conductivity over 10-4 S cm-1 at room temperature. Glass-ceramics were proved to have higher stability against lithium metal than respective glass electrolytes. All-solid-state batteries using the glass and glass-ceramic electrolytes were constructed to evaluate the cell performance as a lithium secondary battery. The cell Li/80Li2S-20P2S5 glass/LiCoO2 performed the best but displayed a large initial irreversible capacity.
Push-Pull Quinoid Dye for Dye Sensitized Solar Cell
Authors: Komatsu Makoto , Tamaki Koichi , Nakazaki Jotaro , Uchida Satoshi , Kubo Takaya , Segawa Hiroshi
Published: March 2009

A novel push-pull quinoid dye [(4-benzo-1,3-dithiol-2-ylidene)quinocyanocarboxymethylene (BDTQCC)] was synthesized as a photosensitizer for dye sensitized solar cell (DSSC). BDTQCC has a broad absorption band between 450 nm and 700 nm derived from the π-π* transition with a charge transfer character. The DSSC using BDTQCC gives incident photon-to-current conversion efficiency (IPCE) of up to 52.1% at 570 nm. Photoelectric conversion in the near-infrared region was confirmed.
Effect of Silicotungstic Acid on Photoelectrochemical Properties of Pulse Electrodeposited Cadmium Selenide Films
Authors: Murali K. R. , Manoharan C. , Dhanapandityan S.
Published: March 2009

CdSe films were deposited by the pulse plating technique in the presence of silicotungstic acid.The films deposited in the presence of silicotungstic acid exhibited hexagonal structure. The films exhibited a direct band gap of 1.67 eV. With addition of silsicotungstic acid, the average grain size decreased from 17.1 nm to 11.7 nm, and the grain became more homogeneous.The surface roughness decreased from 2.83 nm to 1.97 ater adding silsicotungstic acid.The efficiency of the photoelectrochemical cells increases with addition of silicotungstic acid.
Preparation of Electrodeposited Pt Nano Patterned Electrode using UV-Nano Imprinting Lithography
Authors: Saito Mikiko , Mizuno Jun , Nishikubo Hideo , Fujiwara Hidemichi , Homma Takayuki
Published: March 2009

We attempt to prepare the patterned electrode for the formation of nano particles using electrochemical deposition with the cathode whose surface has nano dot patterns. In particular, we applied electrodeposition of Pt and UV nano imprinting lithography (UV-NIL) to prepare the nano patterned electrode. In order to achieve higher activity, the deposition condition of Pt was optimized using additives such as polyethylene glycol (PEG). The surface activity of the Pt films was affected by molecular weight of PEG. It was revealed that the surface activity of the films deposited with the order of thousands of molecular weight of PEG indicated the highest effective current density among the examined films. The Pt films, which exhibited the highest current density, were adapted to fabricate nano-patterned electrode with 400 nm pith periodic structure using UV-NIL.
Assembly of CdSeS(ZnS) Quantum Dots in Langmuir Films with Tertiary Alkyl Phosphine Ligands
Authors: Giles Alexander J. , Pagan Jennifer , Patel Kinnari , Stokes E. B.
Published: March 2009

The focus of this paper is to describe studies on pre-prepared hydrophobic CdSeS(ZnS) quantum dots (QDs) at the air-water interface. Surface pressure-area (π-A) isotherms were extensively studied using QDs capped with either trioctylphosphine oxide or triethylphosphine oxide. The role of these two different ligands on monolayer behavior and thin film quality has been investigated using the Langmuir-Blodgett (LB) technique. The thin films were characterized by scanning electron microscopy (SEM), fluorescence spectroscopy, and UV-vis spectroscopy.
Formation Factor of Nodule by Copper Electrodeposition
Authors: Okamoto Naoki , Takahashi Satoshi , Saito Takeyasu , Kondo K.
Published: March 2009

Copper electrodeposition has been used in the formation of the signal line in cellular phones, liquid crystal TVs and digital cameras. Recently, the formation of nodules and large knot deposits became a serious problem because of the downsizing of signal lines pitch in electronic devices. The nodules cause short circuits in the signal lines. In our previous work, we have investigated the origins of the nodules formation. The nodules grow as the growth of the copper electrodeposits and tiny hemispherical deposits are the nucleuses of the nodules. However, numerous unknown factors remain, such as the formation mechanism of the nodules nucleuses. In this report, we further discuss the factors of the nodule formation.
Inflammatory bowel disease causes reversible suppression of osteoblast and chondrocyte function in mice
Authors: Harris Laura , Senagore Patricia , Young Vincent B. , McCabe Laura R.
Published: March 2009

Decreased bone density and stature can occur in pediatric patients with inflammatory bowel disease (IBD). Little is known about how IBD broadly impacts the skeleton. To evaluate the influence of an acute episode of IBD on growing bone, 4-wk-old mice were administered 5% dextran sodium sulfate (DSS) for 5 days to induce colitis and their recovery was monitored. During active disease and early recovery, trabecular bone mineral density, bone volume, and thickness were decreased. Cortical bone thickness, outer perimeter, and density were also decreased, whereas inner perimeter and marrow area were increased. These changes appear to maintain bone strength since measures of moments of inertia were similar between DSS-treated and control mice. Histological (static and dynamic), serum, and RNA analyses indicate that a decrease in osteoblast maturation and function account for changes in bone density. Unlike some conditions of bone loss, marrow adiposity did not increase. Similar to reports in humans, bone length decreased and correlated with decreases in growth plate thickness and chondrocyte marker expression. During disease recovery, mice experienced a growth spurt that led to their achieving final body weights and bone length, density, and gene expression similar to healthy controls. Increased TNF-α and decreased IGF-I serum levels were observed with active disease and returned to normal with recovery. Changes in serum TNF-α (increased) and IGF-I (decreased) paralleled changes in bone parameters and returned to normal values with recovery, suggesting a potential role in the skeletal response.
Apelin prevents aortic aneurysm formation by inhibiting macrophage inflammation
Authors: Leeper Nicholas J. , Tedesco Maureen M. , Kojima Yoko , Schultz Geoffrey M. , Kundu Ramendra K. , Ashley Euan A. , Tsao Phillip S. , Dalman Ronald L. , Quertermous Thomas
Published: March 2009

Apelin is a potent inodilator with recently described antiatherogenic properties. We hypothesized that apelin might also attenuate abdominal aortic aneurysm (AAA) formation by limiting disease-related vascular wall inflammation. C57BL/6 mice implanted with osmotic pumps filled with apelin or saline were treated with pancreatic elastase to create infrarenal AAAs. Mice were euthanized for aortic PCR analysis or followed ultrasonographically and then euthanized for histological analysis. The cellular expression of inflammatory cytokines and chemokines in response to apelin was also assessed in cultured macrophages, smooth muscle cells, and fibroblasts. Apelin treatment resulted in diminished AAA formation, with a 47% reduction in maximal cross-sectional area (0.74 vs. 1.39 mm2, P < 0.03) and a 57% reduction in macrophage infiltrate (113 vs. 261.3 cells/high-power field, P < 0.0001) relative to the saline-treated group. Apelin infusion was also associated with significantly reduced aortic macrophage colony-stimulating factor expression and decreased monocyte chemattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, interleukin (IL)-6, and tumor necrosis factor (TNF)-α mean mRNA levels. Apelin stimulation of cultured macrophages significantly reduced MCP-1 and TNF-α mRNA levels relative to baseline (2.03- and 1.89-fold reduction, P < 0.03, respectively) but did not affect intimal adhesion molecule expression or medial or adventitial cell cytokine production. Apelin significantly reduces aneurysm formation in the elastase model of human AAA disease. The mechanism appears to be decreased macrophage burden, perhaps related to an apelin-mediated decrease in proinflammatory cytokine and chemokine activation.
Bronchoconstriction induced by hyperventilation with humidified hot air: role of TRPV1-expressing airway afferents
Authors: Lin Ruei-Lung , Hayes Don , Lee Lu-Yuan
Published: March 2009

A recent study by our laboratory has shown that an increase in intrathoracic temperature activates vagal pulmonary C-fibers. Because these afferents are known to elicit reflex bronchoconstriction upon stimulation, this study was carried out to investigate if an increase in airway temperature within the physiological range alters bronchomotor tone. Adult guinea pigs were anesthetized and mechanically ventilated via a tracheal tube. After the lung had been hyperventilated with humidified hot air (HHA) for 4 min, the tracheal temperature was elevated from 36.4 to 40.5°C, which induced an immediate bronchoconstriction, increasing total pulmonary resistance ( RL) to 177 ± 10% and decreasing dynamic lung compliance to 81 ± 6% of their respective baselines. The increase in RLreturned spontaneously toward the baseline in <10 min and was reproducible in the same animals. There were no difference in the responses whether the humidity was generated from distilled water or isotonic saline. In contrast, hyperventilation with humidified air at room temperature did not cause any increase in RL. The increase in RLcaused by HHA was attenuated by 65.9% after a pretreatment with atropine alone and by 72.0% after a pretreatment with a combination of atropine and neurokinin receptor type 1 and 2 antagonists. In addition, capsazepine, a selective transient receptor potential vanilloid type 1 (TRPV1) antagonist, reduced the HHA-induced increase in RLby 64.1% but did not abolish it. However, pretreatment with formoterol, a β2-agonist, completely prevented the HHA-induced bronchoconstriction. These results indicate that the increase in airway temperature induced transient airway constriction in guinea pigs. Approximately two-thirds of the increase in bronchomotor tone was mediated through the cholinergic reflex, which was probably elicited by the activation of TRPV1-expressing airway afferents. The remaining bronchoconstriction was caused by other, yet unidentified factors.
Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men
Authors: Hulmi Juha J. , Tannerstedt Jörgen , Selänne Harri , Kainulainen Heikki , Kovanen Vuokko , Mero Antti A.
Published: March 2009

Signaling pathways sense local and systemic signals and regulate muscle hypertrophy. The effects of whey protein ingestion on acute and long-term signaling responses of resistance exercise are not well known. Previously untrained young men were randomized into protein ( n = 9), placebo ( n = 9), and control ( n = 11) groups. Vastus lateralis (VL) muscle biopsies were taken before and 1 h and 48 h after a leg press of 5 × 10 repetitions [resistance exercise (RE)] and after 21 wk (2 times per week) of resistance training (RT). Protein (15 g of whey) or nonenergetic placebo was ingested before and after a single RE bout and each RE workout throughout the RT. The protein group increased its body mass and VL muscle thickness (measured by ultrasonography) already at week 10.5 ( P < 0.05). At week 21, the protein and placebo groups had similarly increased their myofiber size. No changes were observed in the nonexercised controls. However, the phosphorylation of p70S6K and ribosomal protein S6 (rpS6) were increased at 1 h post-RE measured by Western blotting, the former being the greatest with protein ingestion. Mammalian target of rapamycin (mTOR) phosphorylation was increased after the RE bout and RT only in the protein group, whereas the protein ingestion prevented the post-RE decrease in phosphorylated eukaryotic initiation factor 4E binding protein 1 (p-4E-BP1). Akt phosphorylation decreased after RT, whereas no change was observed in phosphorylated eukaryotic elongation factor 2. A post-RE decrease in muscle myostatin protein occurred only in the placebo group. The results indicate that resistance exercise rapidly increases mTOR signaling and may decrease myostatin protein expression in muscle and that whey protein increases and prolongs the mTOR signaling response.
Role of vagal innervation on pulmonary surfactant system during fetal development
Authors: Gahlot Luxmi , Green Francis H. Y. , Rigaux Anita , Schneider Jennifer M. , Hasan Shabih U.
Published: March 2009

Vagally mediated afferent feedback and compliant lungs (surfactant system) play vital roles in the establishment of adequate alveolar ventilation and pulmonary gas exchange at birth. Although the significance of vagal innervation in the establishment of normal breathing patterns is well recognized, the precise role of lung innervation in the maturation of the surfactant system remains unclear. The specific aim of the present study was to investigate whether vagal denervation compromises the surfactant system during fetal development. Experiments were performed on 12 time-dated fetal sheep: 8 underwent cervical vagal denervation, and 4 were sham operated. Vagal denervation was performed at 110–113 days gestation. Fetal lambs were instrumented in utero to record arterial pH and blood-gas tensions. The animals were delivered by cesarean section under general anesthesia between 130 and 133 days gestation (term ∼147 days). Lung samples were collected for wet-to-dry ratios, light and electron microscopy, and overall lung morphology. In addition, total proteins, total phospholipids, and surfactant proteins A and B were analyzed in both lung tissue and bronchoalveolar lavage fluid. Vagal denervation had no effect on alveolar architecture, including type II cells or the morphology of lamellar bodies within them. Furthermore, surfactant proteins A and B and total phospholipids were similar in lung tissue and bronchoalveolar lavage fluid between the two groups. A significant correlation was observed between circulating cortisol concentrations and surfactant proteins in the bronchoalveolar lavage fluid and lung tissue. We provide definitive evidence that vagal innervation at midgestation is not required for maturation of the pulmonary surfactant system during fetal development.
Cerebral metabolic rate of oxygen and amplitude-integrated electroencephalography during early reperfusion after hypoxia-ischemia in piglets
Authors: Tichauer Kenneth M. , Elliott Jonathan T. , Hadway Jennifer A. , Lee Ting-Yim , St. Lawrence Keith
Published: March 2009

The therapeutic window following perinatal hypoxia-ischemia is brief, and early clinical signs of injury can be subtle. Electroencephalography (EEG) represents the most promising early diagnostic of hypoxia-ischemia; however, some studies have questioned the sensitivity and specificity of EEG. The present study investigated the use of both near-infrared spectroscopy (NIRS) measurements of the cerebral metabolic rate of oxygen (CMRO2) and amplitude-integrated EEG (aEEG) to detect the severity of hypoxia-ischemia after 1 h of reperfusion in newborn piglets (10 insult, 3 control). The CMRO2 was measured before and after 1 h of reperfusion from hypoxia-ischemia, the duration of which was varied from piglet to piglet with a range of 3–24 min, under fentanyl/nitrous oxide anesthesia to mimic awake-like levels of cerebral metabolism. EEG data were collected throughout the study. On average, the CMRO2 and mean aEEG background signals were significantly depressed following the insult ( P < 0.05). Mean CMRO2 and mean aEEG background were 2.61 ± 0.11 ml O2·min−1·100 g−1 and 20.4 ± 2.7 μV before the insult and 1.58 ± 0.09 ml O2·min−1·100 g−1 and 11.8 ± 2.9 μV after 1 h of reperfusion, respectively. Both CMRO2 and aEEG displayed statistically significant correlations with duration of ischemia ( P < 0.05; r = 0.71 and r = 0.89, respectively); however, only CMRO2 was sensitive to milder injuries (<5 min). This study highlights the potential for combining NIRS measures of CMRO2 with EEG in the neonatal intensive care unit to improve early detection of perinatal hypoxia-ischemia.
Exercise training reverses age-related decrements in endothelium-dependent dilation in skeletal muscle feed arteries
Authors: Trott Daniel W. , Gunduz Filiz , Laughlin M. Harold , Woodman Christopher R.
Published: March 2009

We tested two hypotheses, first that exercise training reverses age-related decrements in endothelium-dependent dilation in soleus muscle feed arteries and second that this improved endothelium-dependent dilation is the result of increased nitric oxide (NO) bioavailability due to increased content and phosphorylation of endothelial NO synthase (eNOS) and/or increased antioxidant enzyme content. Young (2 mo) and old (22 mo) male Fischer 344 rats were exercise trained (Ex) or remained sedentary (Sed) for 10–12 wk, yielding four groups of rats: 1) young Sed (4–5 mo), 2) young Ex (4–5 mo), 3) old Sed (24–25 mo), and 4) old Ex (24–25 mo). Soleus muscle feed arteries (SFA) were isolated and cannulated with two glass micropipettes for examination of endothelium-dependent (ACh) and endothelium-independent [sodium nitroprusside (SNP)] vasodilator function. To determine the mechanism(s) by which exercise affected dilator responses, ACh-induced dilation was assessed in the presence of Nω-nitro-l-arginine (l-NNA; to inhibit NO synthase), indomethacin (Indo; to inhibit cyclooxygenase), and l-NNA + Indo. Results indicated that ACh-induced dilation was blunted in old Sed SFA relative to young Sed SFA. Exercise training improved ACh-induced dilation in old SFA such that vasodilator responses in old Ex SFA were similar to young Sed and young Ex SFA. Addition of l-NNA, or l-NNA + Indo, abolished the exercise effect. Immunoblot analysis revealed that extracellular superoxide dismutase (SOD) protein content was increased by training in old SFA, whereas eNOS and SOD-1 protein content were not altered. Addition of exogenous SOD, or SOD + catalase, improved ACh-induced dilation in old Sed SFA such that vasodilator responses were similar to young Sed SFA. Addition of l-NNA abolished the effect of exogenous SOD in old Sed arteries. Collectively, these results indicate that exercise training reverses age-induced endothelial dysfunction in SFA by increasing NO bioavailability and that increases in vascular antioxidant capacity may play an integral role in the improvement in endothelial function.
Crystal Structure of [Bis(L-Alaninato)Diaqua]Nickel(II) Dihydrate
Authors: Khatib Awni , Aqra Fathi , Deamer David , Oliver Allen
Published: March 2009

The title complex, [Ni, has been prepared from nickel(II) chloride in aqueous solution by adding L-alanine and potassium hydroxide. It has been crystallized from aqueous solution, and its structure was determined by X-ray structure analysis. The nickel(II) ion adopts distorted octahedral coordination geometry with two bidentate L-alanine molecules and two water molecules. The complex is neutral and dihydrated. The crystal structure shows the hydrogen bonding between water and amide hydrogens within the lattice, and each fragment of the complex contains two water molecules as hydrated water. The L-alaninato ligand skeleton of the compound adopts the most stable trans-III configuration in the solid state. The alternating two five-membered chelate rings are in the stable gauche conformation.
Applicability of Appropriateness Criteria for Stress Imaging
Authors: McCully Robert B. , Pellikka Patricia A. , Hodge David O. , Araoz Philip A. , Miller Todd D. , Gibbons Raymond J.
Published: March 2009

Background—

Appropriateness criteria for stress imaging have been published to promote the effective use of stress nuclear scintigraphy and stress echocardiography. We sought to evaluate the application of the stress echocardiography appropriateness criteria to patients undergoing stress echocardiography in an academic medical center.

Methods and Results—

The stress echocardiography criteria were applied to 298 consecutive patients who underwent stress echocardiography. Patients were rated as appropriate, uncertain, inappropriate, or not classifiable. Results were compared with those of a previous analysis in the same patients using the single-photon computed tomography myocardial perfusion imaging (SPECT MPI) criteria. The level of agreement between 2 cardiac nurse abstractors for categorizing appropriateness by the stress echocardiography criteria was good (κ=0.72). Overall, 54% of patients were classified as appropriate, 8% as uncertain, and 19% as inappropriate; 19% were not classifiable. By the SPECT MPI criteria, 64% of patients were classified as appropriate, 9% as uncertain, and 18% as inappropriate; 9% were not classifiable (
P
<0.001 compared with stress echocardiography criteria). By the stress echocardiography criteria, 6 clinical situations or indications accounted for more than 90% of the inappropriate tests; most of these involved asymptomatic patients.

Conclusions—

Applying stress echocardiography appropriateness criteria to a patient population is feasible, although 1 in 5 of our patients was not classifiable. Overall, the stress echocardiography criteria classified patients differently compared with the SPECT MPI criteria. Future refinements of the appropriateness criteria for stress imaging should address gaps in the criteria and disparities between the stress echocardiography and SPECT MPI criteria.
Endothelium-Dependent Cerebral Artery Dilation Mediated by TRPA1 and Ca
2+
-Activated K
+
Channels
Authors: Earley Scott , Gonzales Albert L. , Crnich Rachael
Published: March 2009

Although it is well established that changes in endothelial intracellular [Ca
2+
] regulate endothelium-dependent vasodilatory pathways, the molecular identities of the ion channels responsible for Ca
2+
influx in these cells are not clearly defined. The sole member of the ankyrin (A) transient receptor potential (TRP) subfamily, TRPA1, is a Ca
2+
-permeable nonselective cation channel activated by electrophilic compounds such as acrolein (tear gas), allicin (garlic), and allyl isothiocyanate (AITC) (mustard oil). The present study examines the hypothesis that Ca
2+
influx via TRPA1 causes endothelium-dependent vasodilation. The effects of TRPA1 activity on vascular tone were examined using isolated, pressurized cerebral arteries. AITC induced concentration-dependent dilation of pressurized vessels with myogenic tone that was accompanied by a corresponding decrease in smooth muscle intracellular [Ca
2+
]. AITC-induced dilation was attenuated by disruption of the endothelium and when the TRPA1 channel blocker HC-030031 was present in the arterial lumen. TRPA1 channels were found to be present in native endothelial cells, localized to endothelial cell membrane projections proximal to vascular smooth muscle cells. AITC-induced dilation was insensitive to nitric oxide synthase or cyclooxygenase inhibition but was blocked by luminal administration of the small and intermediate conductance Ca
2+
-activated K
+
channel blockers apamin and TRAM34. BaCl
2
, a blocker of inwardly rectifying K
+
channels, also inhibited AITC-induced dilation. AITC-induced smooth muscle cell hyperpolarization was blocked by apamin and TRAM34. We conclude that Ca
2+
influx via endothelial TRPA1 channels elicits vasodilation of cerebral arteries by a mechanism involving endothelial cell Ca
2+
-activated K
+
channels and inwardly rectifying K
+
channels in arterial myocytes.
T Cell–Mediated Inflammation in Adipose Tissue Does Not Cause Insulin Resistance in Hyperlipidemic Mice
Authors: Sultan Ariane , Strodthoff Daniela , Robertson Anna-Karin , Paulsson-Berne Gabrielle , Fauconnier Jeremy , Parini Paolo , Rydén Mikael , Thierry-Mieg Nicolas , Johansson Maria E. , Chibalin Alexander V. , Zierath Juleen R. , Arner Peter , Hansson Göran K.
Published: March 2009

Obesity is associated with chronic inflammation in adipose tissue. Proinflammatory cytokines including tumor necrosis factor-α and interleukin-6 secreted by adipose tissue during the metabolic syndrome are proposed to cause local and general insulin resistance and promote development of type 2 diabetes. We have used a compound mutant mouse,
Apoe
−/−
×CD4dnTGFbR, with dysregulation of T-cell activation, excessive production of proinflammatory cytokines, hyperlipidemia, and atherosclerosis, to dissect the role of inflammation in adipose tissue metabolism. These mice are lean, which avoids confounding effects of concomitant obesity. Expression and secretion of a set of proinflammatory factors including tumor necrosis factor-α, interferon-γ, and monocyte chemoattractant protein-1 was increased in adipose tissue of
Apoe
−/−
×CD4dnTGFbR mice, as was the enzyme 11β-hydroxysteroid dehydrogenase type 1, which converts cortisone to bioactive cortisol. Interleukin-6, which has an inhibitory glucocorticoid response element in its promoter, was not upregulated. In spite of intense local inflammation, insulin sensitivity was not impaired in adipose tissue of
Apoe
−/−
×CD4dnTGFbR mice unless exogenous interleukin-6 was administered. In conclusion, T-cell activation causes inflammation in adipose tissue but does not lead to insulin resistance in this tissue in the absence of interleukin-6.
Biochemical and Mechanical Dysfunction in a Mouse Model of Desmin-Related Myopathy
Authors: Maloyan Alina , Osinska Hanna , Lammerding Jan , Lee Richard T. , Cingolani Oscar H. , Kass David A. , Lorenz John N. , Robbins Jeffrey
Published: March 2009

An R120G mutation in αB-crystallin (CryAB
R120G
) causes desmin-related myopathy (DRM). In mice with cardiomyocyte-specific expression of the mutation, CryAB
R120G
-mediated DRM is characterized by CryAB and desmin accumulations within cardiac muscle, mitochondrial deficiencies, activation of apoptosis, and heart failure (HF). Excessive production of reactive oxygen species (ROS) is often a hallmark of HF and treatment with antioxidants can sometimes prevent the progression of HF in terms of contractile dysfunction and cardiomyocyte survival. It is unknown whether blockade of ROS is beneficial for protein misfolding diseases such as DRM. We addressed this question by blocking the activity of xanthine oxidase (XO), a superoxide-generating enzyme that is upregulated in our model of DRM. The XO inhibitor oxypurinol was administered to CryAB
R120G
mice for a period of 1 or 3 months. Mitochondrial function was dramatically improved in treated animals in terms of complex I activity and conservation of mitochondrial membrane potential. Oxypurinol also largely restored normal mitochondrial morphology. Surprisingly, however, cardiac contractile function and cardiac compliance were unimproved, indicating that the contractile deficit might be independent of mitochondrial dysfunction and the initiation of apoptosis. Using magnetic bead microrheology at the single cardiomyocyte level, we demonstrated that sarcomeric disarray and accumulation of the physical aggregates resulted in significant changes in the cytoskeletal mechanical properties in the CryAB
R120G
cardiomyocytes. Our findings indicate that oxypurinol treatment largely prevented mitochondrial deficiency in DRM but that contractility was not improved because of mechanical deficits in passive cytoskeletal stiffness.
Reduction in Incident Stroke Risk With Vigorous Physical Activity
Authors: Williams Paul T.
Published: March 2009

Background and Purpose—

The purpose of this study was to assess the dose–response relationship between vigorous physical activity (running distance, km/d) and the participant-reported physician-diagnosed stroke.

Methods—

Age-adjusted survival analysis of 29 279 men and 12 123 women followed prospectively for 7.7 years.

Results—

One hundred men and 19 women reported incident strokes. Per km/d run, the age- and smoking-adjusted risk for stroke decreased 12% in men (
P
=0.0007), and 11% in men and women combined (
P
=0.001), which remained significant when further adjusted for baseline diabetes, hypercholesterolemia, hypertension, and BMI (8% and 7% reduction per km/d run, respectively,
P
=0.03). Men and women who ran ≥2 km/d (ie, exceeded the recommended AHA/CDC and NIH guideline activity level) had significantly lower risk than those who ran less (
P
=0.05), and those who ran ≥4 km/d had significantly lower risk than those who ran 2 to 3.9 km/d (
P
=0.02). Men and women who ran ≥8 km/d were at 60% lower risk than those who ran <2 km/d (
P
=0.002).

Conclusions—

The risk for incident stroke is substantially reduced in those who exceed the guideline physical activity level, which cannot be attributed to less hypertension, diabetes, hypercholesterolemia, or body weight.
Abciximab Is a Safe Rescue Therapy in Thromboembolic Events Complicating Cerebral Aneurysm Coil Embolization
Authors: Ries Thorsten , Siemonsen Susanne , Grzyska Ulrich , Zeumer Hermann , Fiehler Jens
Published: March 2009

Background and Purpose—

The purpose of this study was to estimate the safety and efficacy of abciximab treatment in combination with prophylactic heparin, acetylsalicylic acid (ASA), and clopidogrel application in cases of thrombus formation complicating endovascular coil embolization in cerebral aneurysms.

Methods—

Thromboembolic incidents during endovascular management of 515 consecutive cerebral aneurysms were observed in 48 cases (9.3%). Eight incidents were observed during embolization of incidental aneurysms (8/174; 4.6%, 95% CI: 2.0 to 8.9%). All patients underwent anticoagulation with heparin and platelet-inhibition with ASA during treatment procedure. In addition, clopidogrel orally was applied 3 days preoperatively in patients with incidental aneurysms. In case of thrombus formation, glycoprotein IIb-IIIa inhibitor abciximab was given in 42 cases. No coagulation-effective rescue treatment was conducted in 5 cases. One patient was treated with r-tPA. End points were infarction on follow-up cranial CT and the rate of intracranial hemorrhages.

Results—

No infarcts on follow-up CT were observed after treatment with abciximab in 29/42 patients (69.0%, 95% CI: 52.9 to 82.4%). No coagulant rescue therapy was applied in 5 patients because of a small nonocclusive thrombus or good collateral blood supply, showing consecutive infarction on follow-up CT in 3 cases as did the 1 patient treated with r-tPA. No periprocedural bleedings or rebleedings were observed in any case.

Conclusion—

Abciximab was safe as rescue treatment in cases of thrombus formation during endovascular aneurysm coiling. In our study the use of Abciximab, in combination with prophylactic anticoagulation and antiaggregation, does not lead to additional intracranial hemorrhages or any extracranial bleeding complications.
Visual and Semantic Processing of Living Things and Artifacts: An fMRI Study
Authors: Zannino Gian Daniele , Buccione Ivana , Perri Roberta , Macaluso Emiliano , Lo Gerfo Emanuele , Caltagirone Carlo , Carlesimo Giovanni A.
Published: March 2009

We carried out an fMRI study with a twofold purpose: to investigate the relationship between networks dedicated to semantic and visual processing and to address the issue of whether semantic memory is subserved by a unique network or by different subsystems, according to semantic category or feature type. To achieve our goals, we administered a word–picture matching task, with within-category foils, to 15 healthy subjects during scanning. Semantic distance between the target and the foil and semantic domain of the target–foil pairs were varied orthogonally. Our results suggest that an amodal, undifferentiated network for the semantic processing of living things and artifacts is located in the anterolateral aspects of the temporal lobes; in fact, activity in this substrate was driven by semantic distance, not by semantic category. By contrast, activity in ventral occipito-temporal cortex was driven by category, not by semantic distance. We interpret the latter finding as the effect exerted by systematic differences between living things and artifacts at the level of their structural representations and possibly of their lower-level visual features. Finally, we attempt to reconcile contrasting data in the neuropsychological and functional imaging literature on semantic substrate and category specificity.
On the Processing of Semantic Aspects of Experience in the Anterior Medial Temporal Lobe: An Event-related fMRI Study
Authors: Meyer Patric , Mecklinger Axel , Friederici Angela D.
Published: March 2009

Recognition memory based on familiarity judgments is a form of declarative memory that has been repeatedly associated with the anterior medial temporal lobe. It has been argued that this region sustains familiarity-based recognition not only by retrieving item-specific information but also by coding for those semantic aspects of an event that support later familiarity-based recognition. Here, we used event-related fMRI to directly examine whether the contribution of anterior medial temporal lobe to declarative memory indeed results from its role in processing semantic aspects of an event. For this purpose, a sentence comprehension task was employed which varied the demands of semantic and syntactic processing of the sentence-final word. By presenting those sentence-final words together with new words in a subsequent incidental recognition memory test, we were able to determine the mnemonic consequences of presenting words in different sentential contexts. Results showed that enhanced semantic processing during comprehension activates regions in medial temporal lobe cortex and leads to response suppression in partly overlapping regions when the word is successfully retrieved. Data from a behavioral follow-up study support the view that enhanced semantic processing at study enhances familiarity-based remembering in a subsequent test phase.
Neural Systems underlying Lexical Competition: An Eye Tracking and fMRI Study
Authors: Righi Giulia , Blumstein Sheila E. , Mertus John , Worden Michael S.
Published: March 2009

The present study investigated the neural bases of phonological onset competition using an eye tracking paradigm coupled with fMRI. Eighteen subjects were presented with an auditory target (e.g., beaker) and a visual display containing a pictorial representation of the target (e.g., beaker), an onset competitor (e.g., beetle), and two phonologically and semantically unrelated objects (e.g., shoe, hammer). Behavioral results replicated earlier research showing increased looks to the onset competitor compared to the unrelated items. fMRI results showed that lexical competition induced by shared phonological onsets recruits both frontal structures and posterior structures. Specifically, comparison between competitor and no-competitor trials elicited activation in two nonoverlapping clusters in the left IFG, one located primarily within BA 44 and the other primarily located within BA 45, and one cluster in the left supramarginal gyrus (SMG) extending into the posterior superior temporal gyrus. These results indicate that the left IFG is sensitive to competition driven by phonological similarity and not only to competition among semantic/conceptual factors. Moreover, they indicate that the SMG is not only recruited in tasks requiring access to lexical form but is also recruited in tasks that require access to the conceptual representation of a word.
Audiovisual Matching in Speech and Nonspeech Sounds: A Neurodynamical Model
Authors: Loh Marco , Schmid Gabriele , Deco Gustavo , Ziegler Wolfram
Published: March 2009

Audiovisual speech perception provides an opportunity to investigate the mechanisms underlying multimodal processing. By using nonspeech stimuli, it is possible to investigate the degree to which audiovisual processing is specific to the speech domain. It has been shown in a match-to-sample design that matching across modalities is more difficult in the nonspeech domain as compared to the speech domain. We constructed a biophysically realistic neural network model simulating this experimental evidence. We propose that a stronger connection between modalities in speech underlies the behavioral difference between the speech and the nonspeech domain. This could be the result of more extensive experience with speech stimuli. Because the match-to-sample paradigm does not allow us to draw conclusions concerning the integration of auditory and visual information, we also simulated two further conditions based on the same paradigm, which tested the integration of auditory and visual information within a single stimulus. New experimental data for these two conditions support the simulation results and suggest that audiovisual integration of discordant stimuli is stronger in speech than in nonspeech stimuli. According to the simulations, the connection strength between auditory and visual information, on the one hand, determines how well auditory information can be assigned to visual information, and on the other hand, it influences the magnitude of multimodal integration.
Emergent Oscillations in Evolutionary Simulations: Oscillating Networks Increase Switching Efficacy
Authors: Heerebout Bram T. , Phaf R. Hans
Published: March 2009

LeDoux [LeDoux, J. E. The emotional brain. New York: Simon & Schuster, 1996] motivated the direct route in his dual-pathway model by arguing that the ability to switch rapidly between different modes of behavior is highly adaptive. This motivation was supported by evolutionary simulations [den Dulk, P., Heerebout, B. T., & Phaf, R. H. A computational study into the evolution of dual-route dynamics for affective processing. Journal of Cognitive Neuroscience, 15, 194–208, 2003], in which foraging agents, controlled by simple inheritable neural networks, navigated an artificial world while avoiding predation. After many generations, a dual-processing architecture evolved that enabled a rapid switch to avoidance behavior when a predator appeared. We added recurrent connections to a new “context” layer in the indirect pathway to provide the agents with a working memory of previous input (i.e., a “context”). Unexpectedly, agents with oscillating networks emerged that had a much higher fitness than agents without oscillations. Oscillations seemed to have similar effects on switching speed as the dual-processing architecture, but they enhanced switching efficacy to a much larger degree. There has been much neurobiological speculation on the function, if any, of neural oscillations. These findings suggest that the facilitation of switching behavior is a likely candidate. Moreover, the strongly improved adaptation in the simulations contradicts the position that neural oscillations are merely a by-product of cell firing and have no functional value [Pareti, G., & De Palma, A. Does the brain oscillate? The dispute on neuronal synchronization. Neurological Sciences, 25, 41–47, 2004].