bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of reactive oxygen species in skeletal muscle by myostatin is mediated through NF‐κB
Authors: Sriram Sandhya , Subramanian Subha , Sathiakumar Durga , Venkatesh Rithika , Salerno Monica S. , McFarlane Craig D. , Kambadur Ravi , Sharma Mridula 
Published: July 2011

SummaryAbnormal levels of reactive oxygen species (ROS) and inflammatory cytokines have been observed in the skeletal muscle during muscle wasting including sarcopenia. However, the mechanisms that signal ROS production and prolonged maintenance of ROS levels during muscle wasting are not fully understood. Here, we show that myostatin (Mstn) is a pro‐oxidant and signals the generation of ROS in muscle cells. Myostatin, a transforming growth factor‐β (TGF‐β) family member, has been shown to play an important role in skeletal muscle wasting by increasing protein degradation. Our results here show that Mstn induces oxidative stress by producing ROS in skeletal muscle cells through tumor necrosis factor‐α (TNF‐α) signaling via NF‐κB and NADPH oxidase. Aged Mstn null (Mstn−/−) muscles, which display reduced sarcopenia, also show an increased basal antioxidant enzyme (AOE) levels and lower NF‐κB levels indicating efficient scavenging of excess ROS. Additionally, our results indicate that both TNF‐α and hydrogen peroxide (H2O2) are potent inducers of Mstn and require NF‐κB signaling for Mstn induction. These results demonstrate that Mstn and TNF‐α are components of a feed forward loop in which Mstn triggers the generation of second messenger ROS, mediated by TNF‐α and NADPH oxidase, and the elevated TNF‐α in turn stimulates Mstn expression. Higher levels of Mstn in turn induce muscle wasting by activating proteasomal‐mediated catabolism of intracellular proteins. Thus, we propose that inhibition of ROS induced by Mstn could lead to reduced muscle wasting during sarcopenia.
Metal cation binding by the hyperthermophilic microorganism, Archaea Methanocaldococcus Jannaschii, and its effects on silicification
Authors: ORANGE FRANÇOIS , DISNAR JEAN‐ROBERT , WESTALL FRANCES , PRIEUR DANIEL , BAILLIF PATRICK 
Published: July 2011

Abstract:  A series of experiments was conducted to determine the capacity of an archaeal strain, Methanocaldococcus jannaschii, to bind metals and to study the effects of metal binding on the subsequent silicification of the microorganisms. The results showed that M. jannaschii can rapidly bind several metal cations (Fe3+, Ca2+, Pb2+, Zn2+, Cu2+). Considering the lack of silicification of this strain without metal binding, these experiments demonstrate that Fe(III) ion binding to the cell wall components was of fundamental importance for successful silicification and, especially, for the excellent preservation of the cell wall. This study brings new elements to the understanding of fossilization processes, showing that the positive effect of Fe(III) on silicification, already known for Bacteria, can also apply to Archaea and that this preliminary binding can be decisive for the subsequent fossilization of these organisms. Knowledge of these mechanisms can be helpful for the search and the identification of microfossils in both terrestrial and extraterrestrials rocks, and in particular on Mars.
Are Lead Risk Questionnaires Adequate Predictors of Blood Lead Levels in Children?
Authors: Dyal Brenda 
Published: July 2011

ABSTRACT Objective: To evaluate the accuracy of the verbal lead risk assessment tool in identifying the presence of measurable blood lead levels (BLL) in children.
Design and Sample: A retrospective analysis comparing results of a verbal lead risk assessment tool intended to identify elevated BLL in children with actual capillary fingerstick lead screening laboratory data. Three hundred and forty‐nine children aged 5 years and younger enrolled in Head Start during the 2008–2009 school year were evaluated. Sixty‐nine children had complete data and were included for final analysis.
Measures: Results of the verbal lead risk assessment and laboratory capillary fingerstick BLL.
Results: All 69 children had measurable BLL. The Pass group, 84.3% of the sample, had BLL scores of 2.2±1.5 μg/dl, while the Fail group, 15.7% of the sample, had BLL scores of 1.5±0.65 μg/dl. There was no significant difference in BLL between children that passed the verbal risk assessment and those that failed ( p>.05).
Conclusions: The verbal lead risk assessment did not accurately predict measurable BLL in children. Universal BLL screening for children is necessary to identify low levels of lead so that parents and caretakers of children can be notified and assisted in identifying and eliminating sources of lead exposure.
The Effect of Marker Location Variability on Noninvasive Canine Stifle Kinematics
Authors: Torres Bryan T. , Whitlock Dana , Reynolds Lisa R. , Fu Yang‐Chieh , Navik Judith A. , Speas Abbie L. , Sornborger Andrew , Budsberg Steven C. 
Published: July 2011

Objective:Evaluate the effect of marker placement on kinematics of the canine stifle in 3 distinct hindlimb models.Study Design:In vivo biomechanical study.Animals:Normal adult mixed‐breed dogs (n=5).Methods:Ten retroreflective markers were affixed to the skin on the right rear leg of each dog to establish normal stifle kinematics. Four additional markers were placed around the greater trochanter (GT), 2 cm cranial, caudal, dorsal, and ventral to evaluate single marker placement variability on kinematic model data. Dogs were walked and trotted 5 times through the calibrated space. Sagittal flexion and extension angle waveforms were acquired during each trial with 3 models that were produced simultaneously during each gait. The GT marker was reassigned to 1 of the 4 additional locations (cranial, caudal, dorsal, and ventral) to alter the kinematic model. Comparison of sagittal flexion and extension angle waveforms was performed with Generalized Indicator Function Analysis.Results:Each model provided consistent equivalent sagittal flexion–extension data. Analysis revealed statistically significant differences between all GT locations. The differences were greatest in the cranial and caudal locations for all models.Conclusions:Deviation of the GT marker in the cranial/caudal direction from an anatomically normal position produces a greater degree of difference than deviation in a dorsal/ventral direction.
Comparison ofpH, Lactate, and Glucose Analysis of Equine Synovial Fluid using a Portable Clinical Analyzer with a Bench‐Top Blood Gas Analyzer
Authors: Dechant Julie E. , Symm William A. , Nieto Jorge E. 
Published: July 2011

ObjectiveTo compare agreement between a portable clinical analyzer and laboratory‐based bench‐top analyzer for analysis ofpH, lactate, and glucose concentrations in synovial fluid.Study DesignProspective experimental study.AnimalsClinically normal horses (n=8); 6 horses euthanatized for reasons unrelated to the study; 11 horses that had synoviocentesis for reasons other than sepsis; 7 horses that had synoviocentesis for evaluation of sepsis; and 2 horses without recorded clinical data. Median age of horses was 8 years (range, 1 day to 24 years).MethodsSupernatant from each synovial fluid sample was analyzed forpH, lactate, and glucose concentrations using anABL705 laboratory‐based bench‐top analyzer and i‐STATportable clinical analyzer.Bland–Altman plots were constructed and concordance analysis performed to determine bias and agreement between the 2 analyzers.ResultsThere was acceptable agreement between analyzers for lactate and glucose concentrations, with biases of 0.198 mmol/L and 9 mg/dL and concordance correlation coefficients of 0.97 and 0.96 for lactate and glucose, respectively. The agreement between analyzers forpHwas not acceptable, with a bias of −0.057 and concordance correlation coefficient of 0.89.ConclusionsThis study found that the portable clinical analyzer performed similarly to the bench‐top blood gas analyzer for evaluation of lactate and glucose concentrations, but notpH, in synovial fluid.
In Vitro Elution and Antibacterial Activity of Clindamycin, Amikacin, and Vancomycin from R‐gel Polymer
Authors: Thomas Leslie A. , Bizikova Tatiana , Minihan Anne C. 
Published: July 2011

Objective:To characterize the in vitro elution and bioactivity of 2 formulations of antibiotics in a novel, dissolvable, cross‐linked dextran polymer matrix: Formulation 1—amikacin and clindamycin (AC); Formulation 2—amikacin, clindamycin, and vancomycin (ACV).Study Design:Prospective, in vitro, experimental study.Methods:Aliquots of the antibiotic impregnated polymer were incubated in PBS buffer for 10 days. PBS was changed every 24 hours and concentrations of the antibiotics eluted into saline were quantified. Antimicrobial activity of the eluent from each sampling period was tested for growth inhibition ofStaphylococcus aureus.Results:Both formulations of R‐gel™had a rapid initial release of antibiotics within the first 24 hours and then the concentrations decreased gradually over 10 days. The concentration of amikacin, clindamycin, and vancomycin remained above the breakpoint minimum inhibitory concentration of each drug for a minimum of 9 days. No significant difference (P=.9938,P=.9843) was present in the elution pattern or total amount of antibiotic eluted from clindamycin or amikacin, respectively. Eluent from both groups demonstrated bioactivity againstS. aureusfor the entire 10‐day study period.Conclusions:Amikacin and clindamycin together, or in combination with vancomycin, elute from R‐gel™effectively and at gradually decreasing concentrations for at least 10 days. The antibiotics maintained their bioactivity following polymerization and elution from the R‐gel™.
Perioperative Complications after Full‐Thickness Gastrointestinal Surgery in Cats with Alimentary Lymphoma
Authors: Smith Andrea L. , Wilson Aliya P. , Hardie Robert J. , Krick Erika L. , Schmiedt Chad W. 
Published: July 2011

ObjectiveTo determine perioperative risk factors for complications that occur before hospital discharge after gastrointestinal (GI) surgery in cats with alimentary lymphosarcoma (LSA).Study DesignCase series.AnimalsCats (n=70) with a histopathologically confirmed diagnosis of alimentaryLSAthat had full‐thicknessGIsurgery.MethodsMedical record data (February 1996–March 2009) from 3 academic referral centers were reviewed. Retrieved data included signalment, preoperative clinical signs and laboratory findings, perioperative medications administered, type and location ofGIsurgery performed and outcome until hospital discharge.ResultsIn 38 surgeries, intestinal resection and anastomosis was performed. Gastrotomy and/or enterotomy was performed in 53 surgeries. A preoperative serum albumin concentration <2.5 g/dL was recorded for 11 cases. There was no clinical evidence of postoperative leakage from any biopsy or anastomosis site. Postoperative complications that occurred before hospital discharge included: anorexia or decreased appetite (n=8), hyperthermia (3), pancreatitis (1) and constipation (1).ConclusionsCats with alimentaryLSAdo not appear to be at high risk of postoperative dehiscence after full‐thicknessGIsurgery.
Lymphocyte Populations in Joint Tissues from Dogs with Inflammatory Stifle Arthritis and Associated Degenerative Cranial Cruciate Ligament Rupture
Authors: Muir Peter , Kelly Jennifer L. , Marvel Sarah Jane , Heinrich Daniel A. , Schaefer Susan L. , Manley Paul A. , Tewari Kavita , Singh Anju , Suresh M. , Hao Zhengling , Plisch Erin 
Published: July 2011

Objective:To evaluate lymphocyte populations in stifle synovium and synovial fluid of dogs with degenerative cranial cruciate ligament rupture (CCLR).Study Design:Prospective clinical study.Animals:Dogs (n=25) with stifle arthritis and CCLR, 7 dogs with arthritis associated with cartilage degeneration (osteoarthritis [OA]), and 12 healthy Beagle dogs with intact CCL.Methods:Arthritis was graded radiographically in CCLR dogs. After collection of joint tissues, mononuclear cells were isolated and subsequently analyzed using flow cytometry for expression of CD3, CD4, CD8, and CD21.Results:The proportions of CD4+T helper lymphocytes, CD8+cytotoxic T lymphocytes, and CD3+CD4−CD8−T lymphocytes were increased in synovium from dogs with CCLR compared with synovium from healthy Beagle dogs (P<.05). The proportion of CD3+CD4−CD8−T lymphocytes in synovial fluid was increased in dogs with CCLR compared with dogs with OA (P<.05). In dogs with CCLR, the proportion of CD3+CD4−CD8−T lymphocytes in synovial fluid was inversely correlated with radiographic arthritis (SR=−0.68,P<.005).Conclusion:Lymphocytic inflammation of stifle synovium and synovial fluid is an important feature of the CCLR arthropathy. Lymphocyte populations include T lymphocytes expressing CD4 and CD8, and CD3+CD4−CD8−T lymphocytes. Presence of CD3+CD4−CD8−T lymphocytes was associated with development of stifle synovitis. Further work is needed to fully identify the phenotype of these cells.
Explaining the Magnitude of Liquidity Premia: The Roles of Return Predictability, Wealth Shocks, and State‐Dependent Transaction Costs
Authors: LYNCH ANTHONY W. , TAN SINAN 
Published: July 2011

ABSTRACTConstantinides (1986) documents how the impact of transaction costs on per‐annum liquidity premia in the standard dynamic allocation problem with i.i.d. returns is an order of magnitude smaller than the cost rate itself. Recent papers form portfolios sorted on liquidity measures and find spreads in expected per‐annum return that are the same order of magnitude as the transaction cost spread. When we allow returns to be predictable and introduce wealth shocks calibrated to labor income, transaction costs are able to produce per‐annum liquidity premia that are the same order of magnitude as the transaction cost spread.
Public Pension Promises: How Big Are They and What Are They Worth?
Authors: NOVY‐MARX ROBERT , RAUH JOSHUA 
Published: July 2011

ABSTRACTWe calculate the present value of state employee pension liabilities using discount rates that reflect the risk of the payments from a taxpayer perspective. If benefits have the same default and recovery characteristics as state general obligation debt, the national total of promised liabilities based on current salary and service is $3.20 trillion. If pensions have higher priority than state debt, the value of liabilities is much larger. Using zero‐coupon Treasury yields, which are default‐free but contain other priced risks, promised liabilities are $4.43 trillion. Liabilities are even larger under broader concepts that account for salary growth and future service.
Are Options on Index Futures Profitable for Risk‐Averse Investors? Empirical Evidence
Authors: CONSTANTINIDES GEORGE M. , CZERWONKO MICHAL , CARSTEN JACKWERTH JENS , PERRAKIS STYLIANOS 
Published: July 2011

ABSTRACTAmerican options on the S&P 500 index futures that violate the stochastic dominance bounds of Constantinides and Perrakis (2009) from 1983 to 2006 are identified as potentially profitable trades. Call bid prices more frequently violate their upper bound than put bid prices do, while violations of the lower bounds by ask prices are infrequent. In out‐of‐sample tests of stochastic dominance, the writing of options that violate the upper bound increases the expected utility of any risk‐averse investor holding the market and cash, net of transaction costs and bid‐ask spreads. The results are economically significant and robust.
Systemic Liquidation Risk and the Diversity–Diversification Trade‐Off
Authors: WAGNER WOLF 
Published: July 2011

ABSTRACTThis paper proposes a portfolio choice model in which investors are subject to liquidation risk and (endogenously) face higher costs in the event of joint liquidation (as was observed during the crisis of 2008 to 2009). The risk of joint liquidation creates an incentive for investors to choose heterogeneous portfolios and to rationally forgo diversification benefits. Joint liquidation risk is also reflected in asset prices, resulting in (1) assets with high idiosyncratic risk having low expected returns, and (2) assets that display high correlation with the portfolios of (liquidation‐prone) investors having high expected returns.
Did Structured Credit Fuel the LBO Boom?
Authors: SHIVDASANI ANIL , WANG YIHUI 
Published: July 2011

ABSTRACTThe leveraged buyout (LBO) boom of 2004 to 2007 was fueled by growth in collateralized debt obligations (CDOs) and other forms of securitization. Banks active in structured credit underwriting lent more for LBOs, indicating that bank lending policies linked LBO and CDO markets. LBO loans originated by large CDO underwriters were associated with lower spreads, weaker covenants, and greater use of bank debt in deal financing. Loans financed through structured credit markets did not lead to worse LBOs, overpayment, or riskier deal structures. Securitization markets altered banks' access to capital, affected their lending policies, and fueled the recent LBO boom.
Rollover Risk and Market Freezes
Authors: ACHARYA VIRAL V. , GALE DOUGLAS , YORULMAZER TANJU 
Published: July 2011

ABSTRACTThe debt capacity of an asset is the maximum amount that can be borrowed using the asset as collateral. We model a sudden collapse in the debt capacity of good collateral. We assume short‐term debt that must be frequently rolled over, a small transaction cost of selling collateral in the event of default, and a small probability of meeting a buy‐to‐hold investor. We then show that a small change in the asset's fundamental value can be associated with a catastrophic drop in the debt capacity, the kind of market freeze observed during the crisis of 2007 to 2008.
Growth of Al2O3 Nanowires on the Cu‐9 at.%Al(111) Single Crystal Surface
Authors: Matolínová Iva , Nemšák Slavomír , Cabala Miloš , Tsud Nataliya , Poltierová‐Vejpravová Jana , Veltruská Kateřina , Yoshitake Michiko , Matolín Vladimír 
Published: July 2011

Aluminum oxide structures were grown on Cu–9 at.%Al(111) single crystals. Usually alumina grows in the form of an epitaxial thin film. The process is based on Al atom segregation and subsequent oxidation of the Al topmost surface. Strong temperature dependence of the alumina growth mode was observed during the oxidation of a Cu–9 at.%Al single crystal. In this work we have reported for the first time the formation of alumina wire‐like nanostructures on the substrate surface during high‐temperature oxidation at low pressure. The nanowire growth was observed during substrate annealing at 1070 K while annealing at 910 K led to the formation of a flat and continuous thin alumina layer. Morphology, chemical composition, and structure characterization of the prepared nanostructures was done by means of scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction. The experimental results point to the formation of Θ alumina phase nanowires due to surface segregation of Al atoms. Mechanism of alumina nanostructure formation is discussed. The experiment clearly showed that nanowire oxide structure growth can be obtained by a bottom‐up process with a mass transfer from the substrate to the assembled nanostructure.
Highly Transmitting ZrO2‐Doped Lu2O3 Ceramics from Combustion Synthesized Powders
Authors: Zou Xiaoqing , Yi Hailan , Zhou Guohong , Chen Shi , Yang Yan , Wang Shiwei 
Published: July 2011

Before shaping, Lu2O3 powders doped with different ZrO2 concentrations were synthesized by a simple combustion method and milled. The shaped green bodies were sintered at 1850°C for 6 h in vacuum. The transmittance and microstructure of the resultant ceramics were characterized by spectrophotometer and SEM. The effects of ZrO2 concentration on the microstructure and optical property of transparent Lu2O3 ceramics were evaluated. When doped with 5 at.% ZrO2, the Lu2O3 ceramic showed the best optical transmission and the in‐line transmittance reached 70% in the visible spectral region. The addition of ZrO2 was found effectively to prohibit grain growth and to remove residual pores.
Synthesis and Piezoelectricity of Single‐Crystalline (K,Na)NbO3 Nanobars
Authors: Xu Siyang , Li Jing‐Feng 
Published: July 2011

Piezoelectric nanostructures have many important applications in nanodevices and micro‐electro‐mechanical systems. This work developed a topochemical method based on Molten‐Salt Synthesis for synthesizing one‐dimensional nanoscale single crystals of lead‐free (K,Na)NbO3 (KNN) piezoelectric oxides. The synthesis process started from molten‐salt reaction between Nb2O5 powders and KCl to produce high‐aspect‐ratio K2Nb8O21 bar‐shaped particles which were transformed to Nb2O5 nanobars via ion‐exchange and thermal decomposition steps, and finally, KNN nanobars were formed also by molten‐salt reaction among Nb2O5 nanobars as templates, and K2CO3 and Na2CO3 in KCl salts. The as‐synthesized KNN nanobars were proved to be single crystals by transmission electron microscopy. The piezoelectricity of an individual KNN nanobar was confirmed by scanning probe microscopy, as the effective piezoelectric coefficient d33* was measured to be 113 pm/V.
Oxidation of ZrB2 Ceramics Containing SiC as Particles, Whiskers, or Short Fibers
Authors: Silvestroni Laura , Sciti Diletta 
Published: July 2011

The thermal stability of ZrB2‐based composites containing SiC‐chopped fibers was tested in a bottom‐up furnace at 1200°C, 1500°C, and 1700°C for 30 min. The oxidation behavior was studied by X‐ray diffraction, scanning electron microscopy, and weight gain. The degradation induced by oxidation was also evaluated considering the strength decrease of oxidized bars. Baseline ZrB2‐composites containing the same amount of SiC particles or SiC whiskers were tested in the same conditions for comparison.
Energy‐Storage Properties of 0.89Bi0.5Na0.5TiO3–0.06BaTiO3–0.05K0.5Na0.5NbO3 Lead‐Free Anti‐ferroelectric Ceramics
Authors: Gao Feng , Dong Xianlin , Mao Chaoliang , Liu Wei , Zhang Hongling , Yang Lihui , Cao Fei , Wang Genshui 
Published: July 2011

Energy‐storage properties of 0.89Bi0.5Na0.5TiO3–0.06BaTiO3–0.05K0.5Na0.5NbO3 (0.89BNT–0.06BT–0.05KNN) lead‐free ceramics were first investigated. Measurements of dielectric properties together with switching current curves indicate a rather diffuse ferroelectric (FE) to anti‐ferroelectric (AFE) phase transition when heating from 20°C to 90°C. The energy density (W), which was calculated from P–E hysteresis loops, increases linearly with the external electric field when E exceeds AFE‐FE transition field. W is independent of temperature and frequency, and maintains around 0.59 J/cm3 under 5.6 kV/mm in the stable AFE phase region. These properties indicate that 0.89BNT–0.06BT–0.05KNN ceramics might be a promising lead‐free AFE material for energy‐storage capacitor application.
Vanadium‐Tin Oxide Nanoparticles with Gas‐Sensing and Catalytic Activity
Authors: Wang Chien‐Tsung , Chen Miao‐Ting , Lai De‐Lun 
Published: July 2011

Nanopowders of vanadium‐tin oxides were prepared by a co‐precipitation process and characterized for their bulk structures, chemical state, sensing capability, and surface reactivity. The solid solutions (cassiterite) were evaluated as sensing elements in a carbon monoxide gas sensor and as catalysts for methanol oxidation in a fixed‐bed reactor. Sensing and catalytic properties were observed dependent upon doping concentration and oxidation state of vanadia species. The sensor response was favored for lower vanadium loadings (V/Sn = 0.05−0.1), related to the reduced vanadium sites. The catalytic activity for methanol conversion was favored for higher vanadium loadings (V/Sn = 0.15−0.2), related to the oxidized vanadium sites. Results demonstrate that the V–O–Sn structure provides redox activity to facilitate oxygen activation for CO gas‐sensing response and promote methanol partial oxidation to formaldehyde. Mechanistic aspects that elucidate the redox pathways are discussed. These oxide nanostructures are promising ceramic materials for use in sensing and catalysis fields involving electron transfer.