bluuebunny/crossref_metadata_2025 huggingface dataset:
Angiotensin receptor-mediated oxidative stress is associated with impaired cardiac redox signaling and mitochondrial function in insulin-resistant rats
Authors: Vázquez-Medina José Pablo , Popovich Irina , Thorwald Max A. , Viscarra Jose A. , Rodriguez Ruben , Sonanez-Organis Jose G. , Lam Lisa , Peti-Peterdi Janos , Nakano Daisuke , Nishiyama Akira , Ortiz Rudy M.
Published: June 2013

Activation of angiotensin receptor type 1 (AT1) contributes to NADPH oxidase (Nox)-derived oxidative stress during metabolic syndrome. However, the specific role of AT1 in modulating redox signaling, mitochondrial function, and oxidative stress in the heart remains more elusive. To test the hypothesis that AT1 activation increases oxidative stress while impairing redox signaling and mitochondrial function in the heart during diet-induced insulin resistance in obese animals, Otsuka Long Evans Tokushima Fatty (OLETF) rats ( n = 8/group) were treated with the AT1 blocker (ARB) olmesartan for 6 wk. Cardiac Nox2 protein expression increased 40% in OLETF compared with age-matched, lean, strain-control Long Evans Tokushima Otsuka (LETO) rats, while mRNA and protein expression of the H2O2-producing Nox4 increased 40–100%. ARB treatment prevented the increase in Nox2 without altering Nox4. ARB treatment also normalized the increased levels of protein and lipid oxidation (nitrotyrosine, 4-hydroxynonenal) and increased the redox-sensitive transcription factor Nrf2 by 30% and the activity of antioxidant enzymes (SOD, catalase, GPx) by 50–70%. Citrate synthase (CS) and succinate dehydrogenase (SDH) activities decreased 60–70%, whereas cardiac succinate levels decreased 35% in OLETF compared with LETO, suggesting that mitochondrial function in the heart is impaired during obesity-induced insulin resistance. ARB treatment normalized CS and SDH activities, as well as succinate levels, while increasing AMPK and normalizing Akt, suggesting that AT1 activation also impairs cellular metabolism in the diabetic heart. These data suggest that the cardiovascular complications associated with metabolic syndrome may result from AT1 receptor-mediated Nox2 activation leading to impaired redox signaling, mitochondrial activity, and dysregulation of cellular metabolism in the heart.
Preservation of left ventricular function and morphology in volume-loaded versus volume-unloaded heterotopic heart transplants
Authors: Didié Michael , Biermann Daniel , Buchert Ralph , Hess Andreas , Wittköpper Katrin , Christalla Peter , Döker Stephan , Jebran Fawad , Schöndube Friedrich , Reichenspurner Hermann , El-Armouche Ali , Zimmermann Wolfram-Hubertus
Published: June 2013

Total mechanical unloading of the heart in classical models of heterotopic heart transplantation leads to cardiac atrophy and functional deterioration. In contrast, partial unloading of failing human hearts with left ventricular (LV) assist devices (LVADs) can in some patients ameliorate heart failure symptoms. Here we tested in heterotopic rat heart transplant models whether partial volume-loading (VL; anastomoses: aorta of donor to aorta of recipient, pulmonary artery of donor to left atrium of donor, superior vena cava of donor to inferior vena cava of recipient; n = 27) is superior to the classical model of myocardial unloading (UL; anastomoses: aorta of donor to aorta of recipient, pulmonary artery of donor to inferior vena cava of recipient; n = 14) with respect to preservation of ventricular morphology and function. Echocardiography, magnetic resonance imaging, and LV-pressure-volume catheter revealed attenuated myocardial atrophy with ∼30% higher LV weight and better systolic contractile function in VL compared with UL (fractional area shortening, 34% vs. 18%; maximal change in pressure over time, 2,986 ± 252 vs. 2,032 ± 193 mmHg/s). Interestingly, no differences in fibrosis (Picrosirus red staining) or glucose metabolism (2-[18F]-fluoro-2-deoxy-D-glucose-PET) between VL and UL were observed. We conclude that the rat model of partial VL attenuates atrophic remodelling and shows superior morphological as well as functional preservation, and thus should be considered more widely as a research model.
Post-translational modifications of the cardiac Na channel: contribution of CaMKII-dependent phosphorylation to acquired arrhythmias
Authors: Herren Anthony W. , Bers Donald M. , Grandi Eleonora
Published: June 2013

The voltage-gated Na channel isoform 1.5 (NaV1.5) is the pore forming α-subunit of the voltage-gated cardiac Na channel, which is responsible for the initiation and propagation of cardiac action potentials. Mutations in the SCN5A gene encoding NaV1.5 have been linked to changes in the Na current leading to a variety of arrhythmogenic phenotypes, and alterations in the NaV1.5 expression level, Na current density, and/or gating have been observed in acquired cardiac disorders, including heart failure. The precise mechanisms underlying these abnormalities have not been fully elucidated. However, several recent studies have made it clear that NaV1.5 forms a macromolecular complex with a number of proteins that modulate its expression levels, localization, and gating and is the target of extensive post-translational modifications, which may also influence all these properties. We review here the molecular aspects of cardiac Na channel regulation and their functional consequences. In particular, we focus on the molecular and functional aspects of Na channel phosphorylation by the Ca/calmodulin-dependent protein kinase II, which is hyperactive in heart failure and has been causally linked to cardiac arrhythmia. Understanding the mechanisms of altered NaV1.5 expression and function is crucial for gaining insight into arrhythmogenesis and developing novel therapeutic strategies.
Endothelial cells overexpressing IL-8 receptor reduce cardiac remodeling and dysfunction following myocardial infarction
Authors: Zhao Xiangmin , Zhang Wei , Xing Dongqi , Li Peng , Fu Jinyan , Gong Kaizheng , Hage Fadi G. , Oparil Suzanne , Chen Yiu-Fai
Published: June 2013

The endothelium is a dynamic component of the cardiovascular system that plays an important role in health and disease. This study tested the hypothesis that targeted delivery of endothelial cells (ECs) overexpressing neutrophil membrane IL-8 receptors IL8RA and IL8RB reduces acute myocardial infarction (MI)-induced left ventricular (LV) remodeling and dysfunction and increases neovascularization in the area at risk surrounding the infarcted tissue. MI was created by ligating the left anterior descending coronary artery in 12-wk-old male Sprague-Dawley rats. Four groups of rats were studied: group 1: sham-operated rats without MI or EC transfusion; group 2: MI rats with intravenous vehicle; group 3: MI rats with transfused ECs transduced with empty adenoviral vector (Null-EC); and group 4: MI rats with transfused ECs overexpressing IL8RA/RB (1.5 × 106 cells post-MI). Two weeks after MI, LV function was assessed by echocardiography; infarct size was assessed by triphenyltetrazolium chloride (live tissue) and picrosirus red (collagen) staining, and capillary density and neutrophil infiltration in the area at risk were measured by CD31 and MPO immunohistochemical staining, respectively. When compared with the MI + vehicle and MI-Null-EC groups, transfusion of IL8RA/RB-ECs decreased neutrophil infiltration and pro-inflammatory cytokine expression and increased capillary density in the area at risk, decreased infarct size, and reduced MI-induced LV dysfunction. These findings provide proof of principle that targeted delivery of ECs is effective in repairing injured cardiac tissue. Targeted delivery of ECs to infarcted hearts provides a potential novel strategy for the treatment of acute MI in humans.
Breathing nitric oxide plus hydrogen gas reduces ischemia-reperfusion injury and nitrotyrosine production in murine heart
Authors: Shinbo Toshihiro , Kokubo Kenichi , Sato Yuri , Hagiri Shintaro , Hataishi Ryuji , Hirose Minoru , Kobayashi Hirosuke
Published: June 2013

Inhaled nitric oxide (NO) has been reported to decrease the infarct size in cardiac ischemia-reperfusion (I/R) injury. However, reactive nitrogen species (RNS) produced by NO cause myocardial dysfunction and injury. Because H2is reported to eliminate peroxynitrite, it was expected to reduce the adverse effects of NO. In mice, left anterior descending coronary artery ligation for 60 min followed by reperfusion was performed with inhaled NO [80 parts per million (ppm)], H2(2%), or NO + H2, starting 5 min before reperfusion for 35 min. After 24 h, left ventricular function, infarct size, and area at risk (AAR) were assessed. Oxidative stress associated with reactive oxygen species (ROS) was evaluated by staining for 8-hydroxy-2′-deoxyguanosine and 4-hydroxy-2-nonenal, that associated with RNS by staining for nitrotyrosine, and neutrophil infiltration by staining for granulocyte receptor-1. The infarct size/AAR decreased with breathing NO or H2alone. NO inhalation plus H2reduced the infarct size/AAR, with significant interaction between the two, reducing ROS and neutrophil infiltration, and improved the cardiac function to normal levels. Although nitrotyrosine staining was prominent after NO inhalation alone, it was eliminated after breathing a mixture of H2with NO. Preconditioning with NO significantly reduced the infarct size/AAR, but not preconditioning with H2. In conclusion, breathing NO + H2during I/R reduced the infarct size and maintained cardiac function, and reduced the generation of myocardial nitrotyrosine associated with NO inhalation. Administration of NO + H2gases for inhalation may be useful for planned coronary interventions or for the treatment of I/R injury.
Cardioprotection via preserved mitochondrial structure and function in the mPer2-mutant mouse myocardium
Authors: Virag Jitka A. I. , Anderson Ethan J. , Kent Susan D. , Blanton Harrison D. , Johnson Tracy L. , Moukdar Fatiha , DeAntonio Jonathan H. , Thayne Kathleen , Ding Jian M. , Lust Robert M.
Published: June 2013

We have previously shown that myocardial infarct size in nonreperfused hearts of mice with a functional deletion of the circadian rhythm gene mPer2 (mPer2-M) was reduced by 43%. We hypothesized that acute ischemia-reperfusion injury (I/R = 30 min I/2 h R) would also be reduced in these mice and that ischemic preconditioning (IPC) (3 × 5 min cycles) before I/R, which enhances protection in wild-type (WT) hearts, would provide further protection in mPer2-M hearts. We observed a 69 and 75% decrease in infarct size in mPer2-M mouse hearts compared with WT following I/R and IPC, respectively. This was coincident with 67% less neutrophil infiltration and 57% less apoptotic cardiomyocytes. IPC in mPer2-M mice before I/R had 48% less neutrophil density and 46% less apoptosis than their WT counterparts. Macrophage density was not different between WT and mPer2-M I/R, but it was 45% higher in mPer2-M IPC mouse hearts compared with WT IPC. There were no baseline differences in cardiac mitochondrial function between WT and mPer2-M mice, but, following I/R, WT exhibited a marked decrease in maximal O2 consumption supported by complex I-mediated substrates, whereas mPer2-M did not, despite no difference in complex I content. Moreover, cardiac mitochondria from WT mice exhibited a very robust increase in ADP-stimulated O2 consumption in response to exogenously added cytochrome c, along with a high rate of reactive oxygen species production, none of which was exhibited by cardiac mitochondria from mPer2-M following I/R. Taken together, these findings suggest that mPer2 deletion preserves mitochondrial membrane structure and functional integrity in heart following I/R injury, the consequence of which is preservation of myocardial viability. Understanding the mechanisms connecting cardiac events, mitochondrial function, and mPer2 could lead to preventative and therapeutic strategies for at risk populations.
Conditional deletion of FAK in mice endothelium disrupts lung vascular barrier function due to destabilization of RhoA and Rac1 activities
Authors: Schmidt Tracy Thennes , Tauseef Mohammad , Yue Lili , Bonini Marcelo G. , Gothert Joachim , Shen Tang-Long , Guan Jun-Lin , Predescu Sanda , Sadikot Ruxana , Mehta Dolly
Published: June 2013

Loss of lung-fluid homeostasis is the hallmark of acute lung injury (ALI). Association of catenins and actin cytoskeleton with vascular endothelial (VE)-cadherin is generally considered the main mechanism for stabilizing adherens junctions (AJs), thereby preventing disruption of lung vascular barrier function. The present study identifies endothelial focal adhesion kinase (FAK), a nonreceptor tyrosine kinase that canonically regulates focal adhesion turnover, as a novel AJ-stabilizing mechanism. In wild-type mice, induction of ALI by intraperitoneal administration of lipopolysaccharide or cecal ligation and puncture markedly decreased FAK expression in lungs. Using a mouse model in which FAK was conditionally deleted only in endothelial cells (ECs), we show that loss of EC-FAK mimicked key features of ALI (diffuse lung hemorrhage, increased transvascular albumin influx, edema, and neutrophil accumulation in the lung). EC-FAK deletion disrupted AJs due to impairment of the fine balance between the activities of RhoA and Rac1 GTPases. Deletion of EC-FAK facilitated RhoA's interaction with p115-RhoA guanine exchange factor, leading to activation of RhoA. Activated RhoA antagonized Rac1 activity, destabilizing AJs. Inhibition of Rho kinase, a downstream effector of RhoA, reinstated normal endothelial barrier function in FAK−/−ECs and lung vascular integrity in EC-FAK−/−mice. Our findings demonstrate that EC-FAK plays an essential role in maintaining AJs and thereby lung vascular barrier function by establishing the normal balance between RhoA and Rac1 activities.
Designing Interactive Applications to Support Novel Activities
Authors: Lee Hyowon , Mohamad Ali Nazlena , Hardman Lynda
Published: June 2013

R&D in media-related technologies including multimedia, information retrieval, computer vision, and the semantic web is experimenting on a variety of computational tools that, if sufficiently matured, could support many novel activities that are not practiced today. Interactive technology demonstration systems produced typically at the end of their projects show great potential for taking advantage of technological possibilities. These demo systems or “demonstrators” are, even if crude or farfetched, a significant manifestation of the technologists’ visions in transforming emerging technologies into novel usage scenarios and applications. In this paper, we reflect on design processes and crucial design decisions made while designing some successful, web-based interactive demonstrators developed by the authors. We identify methodological issues in applying today’s requirement-driven usability engineering method to designing this type of novel applications and solicit a clearer distinction between designing mainstream applications and designing novel applications. More solution-oriented approaches leveraging design thinking are required, and more pragmatic evaluation criteria is needed that assess the role of the system in exploiting the technological possibilities to provoke further brainstorming and discussion. Such an approach will support a more efficient channelling of the technology-to-application transformation which are becoming increasingly crucial in today’s context of rich technological possibilities.
Postpartum Exercise among Nigerian Women: Issues Relating to Exercise Performance and Self-Efficacy
Authors: Adeniyi A. F. , Ogwumike O. O. , Bamikefa T. R.
Published: June 2013

Physical exercise during postpartum period is beneficial to mothers, and the health gains are abundantly reported. This study characterises the postpartum exercise profile of a group of Nigerian women and reports how their exercise self-efficacies are influenced by sociodemographic characteristics.
Participants were women attending the two largest postnatal clinics in Ibadan, south-western Nigeria. A self-developed questionnaire assessed the socio-demographic and exercise profile of participants, while the Exercise Self-Efficacy Scale assessed their exercise self-efficacy.
About two-third (61.0%) of the participants were not aware that they could undertake physical exercise to enhance postpartum health, and 109 (47.8%) were not engaged in any exercise. Those who exercised did so for less than three days/week, and 89% of the women did not belong to any exercise support group. Exercise self-efficacy was significantly () associated with being in an exercise programme, age, employment, work hours/week, monthly income, and number of pregnancies.
Most of the women were not aware they could engage in postpartum exercise, and about half were not undertaking it. More women with high compared to moderate exercise self-efficacy undertook the exercise. Efforts at increasing awareness, improving exercise self-efficacy and adoption of postpartum exercise are desirable among the Nigerian women.
Prevalence Rate and Risk Factors of Depression in Outpatients with Premature Ejaculation
Authors: Zhang Xiansheng , Gao Jingjing , Liu Jishuang , Xia Lei , Yang Jiajia , Hao Zongyao , Zhou Jun , Liang Chaozhao
Published: June 2013

The purpose of this study is to investigate the prevalence rate and risk factors of depression in outpatients who were diagnosed with PE. Therefore, between September 2009 and September 2011, 1801 outpatients at andrology clinics were enrolled and consented to participate in our survey by completed a verbal questionnaire. It included the following: (1) demographic data (e.g., age, body mass index), (2) PE duration, medical history, and sexual history, (3) self-estimated intravaginal ejaculatory latency times, (4) the Zung Self-rating Depression Scale (SDS), and (5) the National Institute of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and (6) the International Index of Erectile Function (IIEF-5). The results showed that a total of 1,206 patients were diagnosed with PE. The prevalence rate of depression in these PE patients was 26.78%. Depression was associated with PE duration, NIH-CPSI score, and IIEF-5 score. Risk factors for depression specifically included PE durations for 13–24, 25–60, or ≥61 months, CPSI scores of 15–30 or ≥31, and IIEF-5 scores <22. These findings suggested that several associated factors (PE duration, CPSI scores, and IIEF-5 scores) were the risk factors of depression in men with PE.
Modified Palmer Drought Severity Index Based on Distributed Hydrological Simulation
Authors: Yan Denghua , Shi Xiaoliang , Yang Zhiyong , Li Ying , Zhao Kai , Yuan Yong
Published: June 2013

Drought monitoring at large scale is essential for fighting against drought. Aiming at the limitation of acquiring long-time serial soil moisture and actual evapotranspiration for Palmer drought severity index (PDSI), the paper modified the PDSI based on distributed hydrological model on subbasin level in Luanhe river basin, North China. The water balance was simulated using the Soil and Water Assessment Tool (SWAT). Calibration and validation results showed good agreement between simulated and measured discharges, and the SWAT model can be used to predict hydrological processes in the study area. Then the simulation results of main hydrologic components were used to establish PDSI. The verification of the drought indices showed that the modified PDSI based on SWAT model and Palmer drought severity index could better describe the characteristics of regional drought evolution in the Luanhe river basin. High drought frequency areas were mainly distributed in the grassland regions of upstream located in the eastern part of Inner Mongolia plateau, and the drought area had a significant upward trend form 1973 to 2010. Compared with the traditional Palmer drought severity index, the modified PDSI could reflect the spatial heterogeneity of regional drought and improve the physical mechanism of PDSI. The drought monitoring method can provide technical support for comprehensive understanding of drought and effective preventing and relieving of drought disasters.
Innate Immunity and Neuroinflammation
Authors: Shastri Abhishek , Bonifati Domenico Marco , Kishore Uday
Published: June 2013

Inflammation of central nervous system (CNS) is usually associated with trauma and infection. Neuroinflammation occurs in close relation to trauma, infection, and neurodegenerative diseases. Low-level neuroinflammation is considered to have beneficial effects whereas chronic neuroinflammation can be harmful. Innate immune system consisting of pattern-recognition receptors, macrophages, and complement system plays a key role in CNS homeostasis following injury and infection. Here, we discuss how innate immune components can also contribute to neuroinflammation and neurodegeneration.
Asymptotic Behavior of Solutions to the Damped Nonlinear Hyperbolic Equation
Authors: Wang Yu-Zhu
Published: June 2013

We consider the Cauchy problem for the damped nonlinear hyperbolic equation inn-dimensional space. Under small condition on the initial value, the global existence and asymptotic behavior of the solution in the corresponding Sobolev spaces are obtained by the contraction mapping principle.
Robust Fault Tolerant Control for a Class of Time-Delay Systems with Multiple Disturbances
Authors: Cao Songyin , Qiao Jianzhong
Published: June 2013

A robust fault tolerant control (FTC) approach is addressed for a class of nonlinear systems with time delay, actuator faults, and multiple disturbances. The first part of the multiple disturbances is supposed to be an uncertain modeled disturbance and the second one represents a norm-bounded variable. First, a composite observer is designed to estimate the uncertain modeled disturbance and actuator fault simultaneously. Then, an FTC strategy consisting of disturbance observer based control (DOBC), fault accommodation, and a mixedH2/H∞controller is constructed to reconfigure the considered systems with disturbance rejection and attenuation performance. Finally, simulations for a flight control system are given to show the efficiency of the proposed approach.
CO2 Capture in Ionic Liquids: A Review of Solubilities and Experimental Methods
Authors: Torralba-Calleja Elena , Skinner James , Gutiérrez-Tauste David
Published: June 2013

The growing concern of climate change and global warming has in turn given rise to a thriving research field dedicated to finding solutions. One particular area which has received considerable attention is the lowering of carbon dioxide emissions from large‐scale sources, that is, fossil fuel power. This paper focuses on ionic liquids being used as novel media for CO2 capture. In particular, solubility data and experimental techniques are used at a laboratory scale. Cited CO2 absorption data for imidazolium‐, pyrrolidinium‐, pyridinium‐, quaternary‐ammonium‐, and tetra‐alkyl‐phosphonium‐based ionic liquids is reviewed, expressed as mole fractions (X) of CO2 to ionic liquid. The following experimental techniques are featured: gravimetric analysis, the pressure drop method, and the view‐cell method.
Trajectory Estimation of Aircraft in a Double-Satellite Passive Positioning System with the Adjoint Method
Authors: Cao Anzhou , Gao Yanqiu , Zhang Jicai , Lv Xianqing
Published: June 2013

A double-satellite passive positioning system is constructed based on the theory of space geometry, where two observation coordinate systems and a fundamental coordinate system exist. In each observation coordinate system, there exists a ray from the observation satellite to the aircraft. One difficulty lies in that these two rays may not intersect due to the existence of various errors. Under this situation, this work assumes that the middle point of common perpendicular between two rays is the actual position of aircraft. Based on the theory of space geometry, the coordinates of aircraft in the fundamental coordinate system can be determined. A dynamic model with the adjoint method is developed to estimate the trajectory of aircraft during the process of rocket propulsion. By assimilating observations, the trajectory of aircraft can be calculated. Numerical experiments are designed to validate the reasonability and feasibility of this model. Simulated results indicate that even by assimilating a small number of observations, the trajectory of aircraft can be estimated. In addition, the trajectory estimation can become more accurate when more observations are assimilated to the model.
Standardization of Malaysian Adult Female Nasal Cavity
Authors: Lee Chih Fang , Abdullah Mohd. Zulkifly , Ahmad Kamarul Arifin , Lutfi Shuaib Ibrahim
Published: June 2013

This research focuses on creating a standardized nasal cavity model of adult Malaysian females. The methodology implemented in this research is a new approach compared to other methods used by previous researchers. This study involves 26 females who represent the test subjects for this preliminary study. Computational fluid dynamic (CFD) analysis was carried out to better understand the characteristics of the standardized model and to compare it to the available standardized Caucasian model. This comparison includes cross-sectional areas for both half-models as well as velocity contours along the nasal cavities. The Malaysian female standardized model is larger in cross-sectional area compared to the standardized Caucasian model thus leading to lower average velocity magnitudes. The standardized model was further evaluated with four more Malaysian female test subjects based on its cross-sectional areas and average velocity magnitudes along the nasal cavities. This evaluation shows that the generated model represents an averaged and standardized model of adult Malaysian females.
An Approximation Method for Convolution Calderón-Zygmund Operators
Authors: Yu Yunxia , Yang Zhanying
Published: June 2013

We present an approximation method for convolution Calderón-Zygmund operators. We give a uniform approximation accuracy of the operators on the endpoint Triebel-Lizorkin spaceF˙1 0;q   (2<q<∞). Our proof mainly relies on then-dimensional Daubechies wavelet bases and the atomic-molecular approach.
3D Model-Based Simulation Analysis of Energy Consumption in Hot Air Drying of Corn Kernels
Authors: Zhang Shiwei , Kong Ninghua , Zhu Yufang , Zhang Zhijun , Xu Chenghai
Published: June 2013

To determine the mechanism of energy consumption in hot air drying, we simulate the interior heat and mass transfer processes that occur during the hot air drying for a single corn grain. The simulations are based on a 3D solid model. The 3D real body model is obtained by scanning the corn kernels with a high-precision medical CT machine. The CT images are then edited by MIMICS and ANSYS software to reconstruct the three-dimensional real body model of a corn kernel. The Fourier heat conduction equation, the Fick diffusion equation, the heat transfer coefficient, and the mass diffusion coefficient are chosen as the governing equations of the theoretical dry model. The calculation software, COMSOL Multiphysics, is used to complete the simulation calculation. The influence of air temperature and velocity on the heat and mass transfer processes is discussed. Results show that mass transfer dominates during the hot air drying of corn grains. Air temperature and velocity are chosen primarily in consideration of mass transfer effects. A low velocity leads to less energy consumption.
A Crack Identification Method for Bridge Type Structures under Vehicular Load Using Wavelet Transform and Particle Swarm Optimization
Authors: Gökdağ Hakan
Published: June 2013

In this work a crack identification method is proposed for bridge type structures carrying moving vehicle. The bridge is modeled as an Euler-Bernoulli beam, and open cracks exist on several points of the beam. Half-car model is adopted for the vehicle. Coupled equations of the beam-vehicle system are solved using Newmark-Beta method, and the dynamic responses of the beam are obtained. Using these and the reference displacements, an objective function is derived. Crack locations and depths are determined by solving the optimization problem. To this end, a robust evolutionary algorithm, that is, the particle swarm optimization (PSO), is employed. To enhance the performance of the method, the measured displacements are denoised using multiresolution property of the discrete wavelet transform (DWT). It is observed that by the proposed method it is possible to determine small cracks with depth ratio 0.1 in spite of 5% noise interference.
Analysis and Design of a Novel Compact Multiband Printed Monopole Antenna
Authors: Wang Junjun , He Xudong
Published: June 2013

A compact multiband printed monopole antenna is presented. The proposed antenna, composed of a modified broadband T-shaped monopole antenna integrating some band-notch structures in the metallic patch, is excited by means of a microstrip line. To calculate the bandwidth starting frequency (BSF) of the T-shaped broadband antenna, an improved formula is proposed and discussed. The multiband operation is achieved by etching three inverted U-shaped slots on the radiant patch. By changing the length of the notch slots, operation bands of the multiband antenna can be adjusted conveniently. The antenna is simulated in Ansoft HFSS and then fabricated and measured. The measurement results show that the proposed antenna operates at 2.25–2.7 GHz, 3.25–3.6 Hz, 4.95–6.2 GHz, and 7-8 GHz, covering the operation bands of Bluetooth, WiMAX, WLAN, and downlink of X-band satellite communication system and thus making it a proper candidate for the multiband devices.
The Distance Matrices of Some Graphs Related to Wheel Graphs
Authors: Zhang Xiaoling , Song Chengyuan
Published: June 2013

LetDdenote the distance matrix of a connected graphG. The inertia ofDis the triple of integers (n+(D), n0(D), n-(D)), wheren+(D),n0(D), andn-(D)denote the number of positive, 0, and negative eigenvalues ofD, respectively. In this paper, we mainly study the inertia of distance matrices of some graphs related to wheel graphs and give a construction for graphs whose distance matrices have exactly one positive eigenvalue.
Fixed Bed Adsorption Study on Phosphate Removal Using Nanosized FeOOH‐Modified Anion Resin
Authors: Li Nan , Ren Jing , Zhao Lin , Wang Zhong-liang
Published: June 2013

Removal of phosphate from solution using nanosized FeOOH‐modified anion resin was studied in fixed bed column. Effect of bed height and flow rate on the breakthrough curves were investigated. Longer breakthrough time was obtained by increasing the bed height and decreasing the flow rate. Bed service depth time (BDST) model was applied to recount the relationship between bed service time and bed height. The value of N0 was calculated to be 21.4 g/L. Yoon‐Nelson model, which fitted well with the experimental data, is allowable to estimate the breakthrough curves and characteristic parameters for phosphate adsorption in the column filled with nanosized FeOOH‐modified anion resin.
The Study of Magnetorheology of Iron Oxide Nanowires
Authors: Rwei S. P. , Wang L. Y. , Chen M. J.
Published: June 2013

In this work, circular Fe3O4 particles with a diameter of
24 nm and quasicircular Fe3O4 particles with a diameter of
10 nm were synthesized using peptization and coprecipitation methods, respectively.
The coprecipitated particles were further formed into Fe3O4
nanowires at high temperature and high pressure in a strongly alkaline environment. The
optimal environment for forming nanowire was 15 m (molality) NaOH at 120°C for
three days; the resulting proportional relationship between its width and its height, the
aspect ratio, was 50.5/1. In the second part of this study, the nanoparticles and nanowire
were dispersed in silicon oil and formed into magnetorheological (MR) fluids of different
concentrations, before undergoing various MR tests—a shear test, a compression
test, and a creep recovery test. The results revealed that the MR performance of nanowire
fluid was better than that of circular particle fluid, in terms of yield stress
(35 Pa versus 60 Pa), compression displacement (Δd)
(0.19 mm versus 0.44 mm), and creep recovery ratio (82% versus
48%). The experimental results conclude that the nanowire network is more robust than
the nanoparticle network. The test of the storage shelf time revealed that
12 wt% nanowire fluid retained more than 80% of its original yield stress
after three months, indicating slight precipitation in the nanowire fluid. In summary, the
nanowire MR fluid had a stronger MR effect than traditional MR fluid that was prepared
with spherical MR particles.
Blow-up Phenomena and Persistence Properties of Solutions to the Two-Component DGH Equation
Authors: Zhai Panpan , Guo Zhengguang , Wang Weiming
Published: June 2013

This paper is concerned with blow-up phenomena and persistence properties for an integrable two-component Dullin-Gottwald-Holm shallow water system. We give sufficient conditions on the initial data which guarantee blow-up phenomena of solutions in finite time for both periodic and nonperiodic cases, respectively. Furthermore, the persistence properties of solutions to the system are investigated.
Identifying Buried Segments of Active Faults in the Northern Rio Grande Rift Using Aeromagnetic, LiDAR, and Gravity Data, South-Central Colorado, USA
Authors: Grauch V. J. S. , Ruleman C. A.
Published: June 2013

Combined interpretation of aeromagnetic and LiDAR data builds on the strength of the aeromagnetic method to locate normal faults with significant offset under cover and the strength of LiDAR interpretation to identify the age and sense of motion of faults. Each data set helps resolve ambiguities in interpreting the other. In addition, gravity data can be used to infer the sense of motion for totally buried faults inferred solely from aeromagnetic data. Combined interpretation to identify active faults at the northern end of the San Luis Basin of the northern Rio Grande rift has confirmed general aspects of previous geologic mapping but has also provided significant improvements. The interpretation revises and extends mapped fault traces, confirms tectonic versus fluvial origins of steep stream banks, and gains additional information on the nature of active and potentially active partially and totally buried faults. Detailed morphology of surfaces mapped from the LiDAR data helps constrain ages of the faults that displace the deposits. The aeromagnetic data provide additional information about their extents in between discontinuous scarps and suggest that several totally buried, potentially active faults are present on both sides of the valley.
Gastric Tissue Damage Analysis Generated by Ischemia: Bioimpedance, Confocal Endomicroscopy, and Light Microscopy
Authors: Beltran Nohra E. , Garcia Laura E. , Garcia-Lorenzana Mario
Published: June 2013

The gastric mucosa ischemic tissular damage plays an important role in critical care patients’ outcome, because it is the first damaged tissue by compensatory mechanism during shock. The aim of the study is to relate bioimpedance changes with tissular damage level generated by ischemia by means of confocal endomicroscopy and light microscopy. Bioimpedance of the gastric mucosa and confocal images were obtained from Wistar male rats during basal and ischemia conditions. They were anesthetized, and stain was applied (fluorescein and/or acriflavine). The impedance spectroscopy catheter was inserted and then confocal endomicroscopy probe. After basal measurements and biopsy, hepatic and gastric arteries clamping induced ischemia. Finally, pyloric antrum tissue was preserved in buffered formaldehyde (10%) for histology processing using light microscopy. Confocal images were equalized, binarized, and boundary defined, and infiltrations were quantified. Impedance and infiltrations increased with ischemia showing significant changes between basal and ischemia conditions (). Light microscopy analysis allows detection of general alterations in cellular and tissular integrity, confirming gastric reactance and confocal images quantification increments obtained during ischemia.
The Occurrence of Two Species of Entomophthorales (Entomophthoromycota), Pathogens ofSitobion avenaeandMyzus persicae(Hemiptera: Aphididae), in Tunisia
Authors: Ben Fekih Ibtissem , Boukhris-Bouhachem Sonia , Eilenberg Jørgen , Allagui Mohamed Bechir , Jensen Annette Bruun
Published: June 2013

The natural occurrence of entomophthoralean fungi pathogenic towards aphids on cereal and potato crops was investigated in the years 2009, 2010, and 2011. Infected aphids were sampled in three bioclimatic zones in Tunisia (Beja, Cap bon, and Kairouan) and fungal species were determined based on morphological characters such as shape, size, and number of nuclei in the primary conidia. Polymerase Chain Reaction (PCR) on the internal transcribed spacer 1 region (ITS1) was used to verify morphological determination. Both methods gave consistent results and we documented for the first time the natural occurrence of two fungal species from the order Entomophthorales (phylum Entomophthoromycota),Pandora neoaphidisandEntomophthora planchoniana. Both fungi were recorded on the aphid speciesSitobion avenaeandMyzus persicaeon barley ears and potato leaves, respectively. Moreover, natural mixed infections by both species (P. neoaphidisandE. planchoniana) were documented on the target aphids. This investigation provides basic information of entomopathogenic fungi infecting economically important aphids in Tunisia.
Scorpion Peptides: Potential Use for New Drug Development
Authors: Hmed BenNasr , Serria Hammami Turky , Mounir Zeghal Khaled
Published: June 2013

Several peptides contained in scorpion fluids showed diverse array of biological activities with high specificities to their targeted sites. Many investigations outlined their potent effects against microbes and showed their potential to modulate various biological mechanisms that are involved in immune, nervous, cardiovascular, and neoplastic diseases. Because of their important structural and functional diversity, it is projected that scorpion-derived peptides could be used to develop new specific drugs. This review summarizes relevant findings improving their use as valuable tools for new drugs development.
BRAF in Melanoma: Current Strategies and Future Directions
Authors: Salama April K.S. , Flaherty Keith T.
Published: June 2013

Selective BRAF inhibitors have now been established as a standard of care option for patients diagnosed with metastatic melanoma whose tumors carry a BRAF mutation. Their successful development represents a milestone in the treatment of this disease, and has the potential to impact therapy for other malignancies as well. The use of these agents, however, has introduced a number of critical questions about the optimal use and selection of patients for BRAF inhibitor therapy. This review discusses the current status of BRAF inhibitor clinical development, the clinicopathologic features of BRAF-mutated melanoma, as well as strategies for overcoming resistance. Clin Cancer Res; 19(16); 4326–34. ©2013 AACR.
Inhibition of Lung Tumorigenesis by Metformin Is Associated with Decreased Plasma IGF-I and Diminished Receptor Tyrosine Kinase Signaling
Authors: Quinn Brendan J. , Dallos Matthew , Kitagawa Hiroshi , Kunnumakkara Ajaikumar B. , Memmott Regan M. , Hollander M. Christine , Gills Joell J. , Dennis Phillip A.
Published: June 2013

Metformin is the most commonly prescribed drug for type II diabetes and is associated with decreased cancer risk. Previously, we showed that metformin prevented tobacco carcinogen (NNK)–induced lung tumorigenesis in a non-diabetic mouse model, which was associated with decreased IGF-I/insulin receptor signaling but not activation of AMPK in lung tissues, as well as decreased circulating levels of IGF-I and insulin. Here, we used liver IGF-I–deficient (LID) mice to determine the importance of IGF-I in NNK-induced lung tumorigenesis and chemoprevention by metformin. LID mice had decreased lung tumor multiplicity and burden compared with wild-type (WT) mice. Metformin further decreased lung tumorigenesis in LID mice without affecting IGF-I levels, suggesting that metformin can act through IGF-I–independent mechanisms. In lung tissues, metformin decreased phosphorylation of multiple receptor tyrosine kinases (RTK) as well as levels of GTP-bound Ras independently of AMPK. Metformin also diminished plasma levels of several cognate ligands for these RTKs. Tissue distribution studies using [14C]-metformin showed that uptake of metformin was high in liver but four-fold lower in lungs, suggesting that the suppression of RTK activation by metformin occurs predominantly via systemic, indirect effects. Systemic inhibition of circulating growth factors and local RTK signaling are new AMPK-independent mechanisms of action of metformin that could underlie its ability to prevent tobacco carcinogen–induced lung tumorigenesis. Cancer Prev Res; 6(8); 801–10. ©2013 AACR.
Dietary Soy Effects on Mammary Gland Development during the Pubertal Transition in Nonhuman Primates
Authors: Dewi Fitriya N. , Wood Charles E. , Lees Cynthia J. , Willson Cynthia J. , Register Thomas C. , Tooze Janet A. , Franke Adrian A. , Cline J. Mark
Published: June 2013

While epidemiologic studies suggest that soy intake early in life may reduce breast cancer risk, there are also concerns that exposure to soy isoflavones during childhood may alter pubertal development and hormonal profiles. Here, we assessed the effect of a high-soy diet on pubertal breast development, sex hormones, and growth in a nonhuman primate model. Pubertal female cynomolgus monkeys were randomized to receive a diet modeled on a typical North American diet with one of two protein sources for approximately 4.5 years: (i) casein/lactalbumin (CL, n = 12, as control) or (ii) soy protein isolate with a human equivalent dose of 120 mg/d isoflavones (SOY, n = 17), which is comparable to approximately four servings of soy foods. Pubertal exposure to the SOY diet did not alter onset of menarche, indicators of growth and pubertal progression, or circulating estradiol and progesterone concentrations. Greater endometrial area was seen in the SOY group on the first of four postmenarchal ultrasound measurements (P < 0.05). There was a subtle effect of diet on breast differentiation whereby the SOY group showed higher numbers of differentiated large-sized lobular units and a lower proportion with immature ducts following menarche (P < 0.05). Numbers of small lobules and terminal end buds and mammary epithelial cell proliferation did not differ by diet. Expression of progesterone receptor was lower in immature lobules of soy-fed animals (P < 0.05). Our findings suggest that consumption of soy starting before menarche may result in modest effects consistent with a more differentiated breast phenotype in adulthood. Cancer Prev Res; 6(8); 832–42. ©2013 AACR.
Grape Seeds: Ripe for Cancer Chemoprevention
Authors: Katiyar Santosh K. , Athar Mohammad
Published: June 2013

A wide variety of phytochemicals, mostly flavonoids or polyphenolics, have been shown to possess anticarcinogenic activities. Among these are the grape seed proanthocyanidins (GSPs), which are the active ingredients of grape seed extract (GSE). Substantial in vitro and preclinical in vivo studies have shown the chemopreventive efficacy of GSPs against various forms of cancers in different tumor models. In this issue of the journal, Derry and colleagues show that administration of GSE in the diet reduces azoxymethane-induced colon carcinogenesis in an A/J mouse model. The results of this innovative and comprehensive study indicate that inhibition of azoxymethane-induced colon cancer by dietary GSE is mediated through the induction of apoptosis that is associated with alterations in microRNA (miRNA) and cytokine expression profiles as well as β-catenin signaling. Notably, the demonstration that miRNA expression is affected by dietary GSE suggests a novel underlying mechanism for the chemopreventive action of GSE in colon cancer and, potentially, other cancers. Cancer Prev Res; 6(7); 617–21. ©2013 AACR.
Unbiased Metabolite Profiling Indicates That a Diminished Thymidine Pool Is the Underlying Mechanism of Colon Cancer Chemoprevention by Alpha-Difluoromethylornithine
Authors: Witherspoon Mavee , Chen Qiuying , Kopelovich Levy , Gross Steven S. , Lipkin Steven M.
Published: June 2013

The ornithine decarboxylase inhibitor α-difluoromethylornithine (DFMO) is a highly effective chemopreventive agent for colorectal cancer thought to act via polyamine depletion. However, in DFMO-treated patients, mucosal polyamine levels do not directly correlate with colorectal cancer risk. Untargeted metabolite profiling was used to broadly survey DFMO actions on colon cancer cell metabolism. We found that DFMO treatment of ApcMin intestinal tumors and human colorectal cancer cells is associated with reduced levels of folate-dependent metabolites, including S-adenosylmethionine (SAM), thymidine pools, and related pathway intermediates. We hypothesized that unrestrained SAM consumption/regeneration constitutes a futile DFMO-triggered cascade that can steal tetrahydrofolate from thymidylate synthase and thereby diminish thymidine pools. In accord with this hypothesis, DFMO treatment altered the folate cofactor balance and thymidine supplementation prevented DFMO-elicited cytostasis without restoring polyamine levels. These findings suggest that thymidine metabolite pool insufficiency is a fundamental mechanism of DFMO cytostatic activity.

Significance: A previously unappreciated metabolic linkage between polyamine and thymidine biosynthesis is revealed, based on the competing requirement of these pathways for a limited pool of tetrahydrofolate cofactor. This study identifies the first shared mechanism for colorectal cancer chemoprevention and chemotherapy, suggesting a common metabolic target for both premalignant and malignant colon cells. Cancer Discov; 3(9); 1072–81. ©2013 AACR.

See related commentary by Casero, p. 975

This article is highlighted in the In This Issue feature, p. 953