bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of AC Impedance Spectroscopy as Characterization and Diagnostic Tool in Li-Metal Battery Cells
Authors: Lvovich Vadim , Wu James , Bennett William , Demattia Brianne , Miller Thomas
Published: April 2014

Electrochemical Impedance spectroscopy (EIS) is exceptionally powerful and rapidly evolving technique for investigating electrical properties of materials and electrochemical interfacial kinetic processes in wide variety of practical systems and applications. The method offers the most powerful on-line and off-line analysis of the status of investigated media, electrodes, and probes in many different complex time– and space-resolved processes that occur in electrochemical laboratory experiments or over a lifetime of monitored samples, devices, or materials. EIS is useful as an empirical quality control procedure that can also be employed to interpret fundamental electrochemical processes [1, 2]. At NASA Glenn Research Center the EIS technique is being widely and effectively employed in characterization and performance monitoring of rechargeable energy storage devices, such as states of electrodes during charging / discharging cycles in secondary batteries and fuel cells. The technical objective for batteries is to improve the performance of rechargeable cells to meet the energy storage requirements of human missions. The approach is to develop advanced battery components to safely provide substantially higher specific energy for relatively few charge/discharge cycles. In the presented work, impedance spectroscopy and other electrochemical and surface science techniques have been widely applied to monitoring developed lithium-metal battery (LMB) cells, including investigation of the impact of novel ionic liquid electrolytes on cycle life and dendrite growth/suppression on Li anodes. Applications of EIS method allowed for efficient in situ performance monitoring of various types of electrodes and electrolytes used in experimental battery cells. The studies were focused initially on evaluating performance of separate battery components in symmetric lithium coin cells, with a purpose of future complete impedance analysis of full cells with Li anode and dedicated cathode.
Impedance Behavior of Binderless Ni-Mo Composite Oxide Cathode for a Li-O2 Battery via Impedance Spectroscopy
Authors: Nelson Ruben , Kosivi Joyce , Weatherspoon Mark H. , Kalu Eric E. , Zheng Jim P.
Published: April 2014

A lithium-air battery (Li-O2) battery featuring a porous carbon cathode with an electrolessly deposited nickel and molybdenum oxide (Ni-Mo) composite. Cyclical charging and discharging, followed with impedance spectroscopy measurements are performed to gather frequency dependent impedance behavior. Throughout cell cycling, there is a quickly growing impedance trend and increased polarization from product buildup and surface degradation. Impedance at high frequencies is mostly capacitive but does feature some show inductive behavior from instrumentation, cathode design, or other factors typical of gas diffusion cells. Results are presented that provide insight on the reactive impedance behavior at different frequency ranges and at various cycling stages of the cell. This data gives an idea as to the state of the cathode over the course of cycling, which is supported by the images of the physical state of the fabricated cathode.
Lytic Phage in Biosensing
Authors: Sorokulova Iryna , Guntupalli Rajesh , Olsen Eric , Globa Ludmila , Pustovyy Oleg , Vodyanoy Vitaly
Published: April 2014

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) antibody conjugated latex beads have been used to produce a biosensor for discrimination of methicillin resistant (MRSA) and sensitive (MSSA) S. aureus strains. The lytic phages have been converted into phage spheroids and moved onto a biosensor surface by Langmuir-Blodgett technique. The produced biosensors have been tested by a quartz crystal microbalance with dissipation tracking to examine bacteria-phage interactions. Bacteria-spheroid interactions caused reduction of resonance frequency and rise in dissipation energy for both MRSA and MSSA strains. Following the bacterial binding, these sensors have been further exposed to the penicillin-binding protein antibody latex beads. Sensors analyzed with MRSA responded to PBP 2a antibody beads; although sensors tested with MSSA gave no response. This experimental distinction determines an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains.
Citrus Greening (Huanglongbing): Fast Electrochemical Detection and Phytomonitoring of the Trees Diseases
Authors: Volkov Alexander George , Brown Corydon R
Published: April 2014

Citrus greening is probably the most important disease of citrus in the world. Here we show that citrus greening infection induces a very strong decrease in the amplitude of the electrical potential difference in a citrus tree tissue or in a fruit. The non-disruptive method, consisting of a data acquisition system interfaced with computer and identical nonpolarizable reversible electrodes connected to trees, was used for the measuring of electrical potentials and the detection of citrus greening in a tree’s tissue. The amplitude and time dependence of a registered electrical potential difference in a leaf, stem or fruit is sensitive to a tree’s health. Infected trees have a very low DC signal in comparison with healthy citrus trees. This electrophysiological method permits fast detection of citrus greening in citrus trees and can be used for a detection of other diseases in plants and trees. Monitoring the electrical signaling in higher plants represents a promising method to investigate fast electrical communication during environmental changes.
Thermally Stable Electrolyte for Lithium-Ion Batteries
Authors: Park Chi-Kyun , Rubino Robert
Published: April 2014

The weight of gas formed by Li-ion cell components heated to 400°C was studied by DSC. Electrolyte released the most gas – over 70% of its original weight during the heat treatment, while fully charged cathode and anode released gas at 4.6% and 3.9% of their original weight, respectively. Thus, the weight of gas formed during heat treatment by various solvents, LiPF6, and electrolytes containing various solvents or lithium salts was studied. Solvent thermal stability was the key to reducing the gas formation of electrolyte at elevated temperature. Electrolyte containing g-butyrolactone (GBL) solvent delayed the venting of Li-ion cells by approximately 50 °C compared with conventional electrolyte containing carbonate solvents during a hot box test. Cell venting was observed to be due to gas pressure from electrolyte decomposition in the cell.
Synthesis of Conjugated Materials for Organic Photovoltaics and Luminescence
Authors: Výprachtický Drahomír , Pokorná Veronika , Kmínek Ivan , Dzhabarov Vagif , Cimrová Věra
Published: April 2014

We report about new syntheses and improvements in the preparation of monomers which are necessary in the syntheses of conjugated organic materials and polymers. First, the synthesis of a phosphorescent iridium containing monomer, such as the 9-(2,7-dibromocarbazol-9-yl)nonan-2,4-dionato-bis(2-phenylpyridine-N,C2’)iridium(III) complex, is reported. Second, the preparation of a monomer for Suzuki coupling, the 9-(2-ethylhexyl)-2,7-bis-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole, was improved and compared with previous procedures. Finally, the synthesis of two silicon containing monomers, the 4-(2-ethylhexyl)-4′-octyl-5,5′-bis(trimethylstannyl)di-thieno[3,2-b:2′,3′-d]silole and the 2,7-bis-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9'-bis(2-ethylhexyl)dibenzosilole, based on dithienosilole and dibenzosilole structural unit, respectively, was proposed. The synthesis of silicon containing polymer, poly[4,6-bis(3-dodecylthien-2-yl)thieno[3,4-c][1,2,5]thiadiazole-alt-4-(2-ethylhexyl)-4′-octyldithieno[3,2-b:2′,3′-d]silole is reported as well.
Marine Aerosol Drop Size Effects on the Corrosion Behavior of Plain Carbon Steel
Authors: Risteen Bailey E. , Schindelholz Eric , Kelly Robert G.
Published: April 2014

In this research, a novel methodology was developed to study corrosion under aqueous electrolyte drops ranging in diameter from 20-1000 mm, the most common drop sizes found in coastal marine environments. The objective of this work was to examine the relationship between drop size and corrosion attack of bare low carbon steel under simulated atmospheric marine conditions. A drop-on-demand inkjet printer was custom built by coupling a commercial jetting device with a programmable two-axis stage. Singular droplets of sodium chloride (6.2 M NaCl in H2O and 8.7 mM in ethanol) were deposited on polished 1010 steel coupons and then exposed to a 75% relative humidity environment for 24 hours. It was found that, in general, the volume loss increased with drop diameter according to a power law. Corrosion always occurred under drops greater than 150 μm in diameter, but was not consistently observed under drops in the 20-100 mm range. The fraction of drops that showed no corrosion increased with decreasing drop size below 100 μm. However, drops smaller than 100 μm that caused corrosion were found to have the greatest volume loss compared to their salt loading density. Therefore, the manner and geometry in which salt is deposited onto a low carbon steel surface, along with the mode of attack, will significantly affect corrosion loss. From a technical standpoint, these results suggest that service life prediction approaches, including accelerated testing, will more accurately simulate natural atmospheres if electrolyte geometry is taken into account for these materials.
Amperometric Gas Sensors with Ionic Liquid Electrolytes
Authors: Carter Michael T , Stetter Joseph R , Findlay Melvin W , Patel Vinay
Published: April 2014

The behavior of amperometric gas sensors using room temperature ionic liquid electrolytes is discussed. Ionic liquid electrolytes were used to prepare amperometric gas sensors in conventional and novel, printed configurations. These sensors were demonstrated for monitoring two toxic gases: ammonia and ozone. For ammonia sensors, the response was compared to a commercial sensor. The issues surrounding sensor performance are discussed. New results are also presented for ozone and nitrogen dioxide monitoring with second generation printed sensors using ionic liquids.
Understanding Chlorite, Chlorate and Perchlorate Formation When Generating Hypochlorite Using Boron Doped Diamond Film Electrodes
Authors: Hubler David K. , Baygents James C. , Chaplin Brian P. , Farrell James
Published: April 2014

This research used density functional theory for investigating reactions on boron doped diamond (BDD) film electrodes that contribute to unwanted byproduct formation during hypochlorite generation. Clusters containing 10 carbon atoms were used to simulate the diamond electrode surface. The simulations included reactions with hydrogen terminated surfaces, and with surface sites produced by anodic polarization, namely: ≡C•, =C•H, ≡C-O• and =CH-O•. The activation energies for oxidation of chlorine oxyanions via direct electron transfer and via reaction with hydroxyl radicals were calculated. Oxychlorine radicals (ClO•, ClO2
•, ClO3
•) were found to chemically adsorb to both secondary and tertiary carbon atoms on the BDD surface. These chemisorbed intermediates could react with hydroxyl radicals to regenerate the original chlorine oxyanion (ClO−, ClO2
−, ClO3
−), and produce ≡C-O• and =CH-O• sites on the BDD surface. The ≡C-O• and =CH-O• sites also reacted with oxychlorine radicals to form chemisorbed intermediates, which could then be converted to higher oxidation states (ClO2
−, ClO3
−, ClO4
−) via reaction with hydroxyl radicals.
Colonic inflammation and secondary bile acids in alcoholic cirrhosis
Authors: Kakiyama Genta , Hylemon Phillip B. , Zhou Huiping , Pandak William M. , Heuman Douglas M. , Kang Dae Joong , Takei Hajime , Nittono Hiroshi , Ridlon Jason M. , Fuchs Michael , Gurley Emily C. , Wang Yun , Liu Runping , Sanyal Arun J. , Gillevet Patrick M. , Bajaj Jasmohan S.
Published: April 2014

Alcohol abuse with/without cirrhosis is associated with an impaired gut barrier and inflammation. Gut microbiota can transform primary bile acids (BA) to secondary BAs, which can adversely impact the gut barrier. The purpose of this study was to define the effect of active alcohol intake on fecal BA levels and ileal and colonic inflammation in cirrhosis. Five age-matched groups {two noncirrhotic (control and drinkers) and three cirrhotic [nondrinkers/nonalcoholics (NAlc), abstinent alcoholic for >3 mo (AbsAlc), currently drinking (CurrAlc)]} were included. Fecal and serum BA analysis, serum endotoxin, and stool microbiota using pyrosequencing were performed. A subgroup of controls, NAlc, and CurrAlc underwent ileal and sigmoid colonic biopsies on which mRNA expression of TNF-α, IL-1β, IL-6, and cyclooxygenase-2 (Cox-2) were performed. One hundred three patients (19 healthy, 6 noncirrhotic drinkers, 10 CurrAlc, 38 AbsAlc, and 30 NAlc, age 56 yr, median MELD: 10.5) were included. Five each of healthy, CurrAlc, and NAlc underwent ileal/colonic biopsies. Endotoxin, serum-conjugated DCA and stool total BAs, and secondary-to-primary BA ratios were highest in current drinkers. On biopsies, a significantly higher mRNA expression of TNF-α, IL-1β, IL-6, and Cox-2 in colon but not ileum was seen in CurrAlc compared with NAlc and controls. Active alcohol use in cirrhosis is associated with a significant increase in the secondary BA formation compared with abstinent alcoholic cirrhotics and nonalcoholic cirrhotics. This increase in secondary BAs is associated with a significant increase in expression of inflammatory cytokines in colonic mucosa but not ileal mucosa, which may contribute to alcohol-induced gut barrier injury.
Structural and functional prevention of hypoxia-induced pulmonary hypertension by individualized exercise training in mice
Authors: Weissmann Norbert , Peters Dorothea M. , Klöpping Christina , Krüger Karsten , Pilat Christian , Katta Susmitha , Seimetz Michael , Ghofrani Hossein A. , Schermuly Ralph T. , Witzenrath Martin , Seeger Werner , Grimminger Friedrich , Mooren Frank C.
Published: April 2014

Pulmonary hypertension (PH) is a disease with a poor prognosis characterized by a vascular remodeling process and an increase in pulmonary vascular resistance. While a variety of reports demonstrated that exercise training exerts beneficial effects on exercise performance and quality of life in PH patients, it is not known how physical exercise affects vascular remodeling processes occurring in hypoxia-induced PH. Therefore, we investigated the effect of individualized exercise training on the development of hypoxia-induced PH in mice. Training effects were compared with pharmacological treatment with the phosphodiesterase 5 inhibitor Sildenafil or a combination of training plus Sildenafil. Trained mice who received Sildenafil showed a significantly improved walking distance (from 88.9 ± 8.1 to 146.4 ± 13.1 m) and maximum oxygen consumption (from 93.3 ± 2.9 to 105.5 ± 2.2% in combination with Sildenafil, to 102.2 ± 3.0% with placebo) compared with sedentary controls. Right ventricular systolic pressure, measured by telemetry, was at the level of healthy normoxic animals, whereas right heart hypertrophy did not benefit from training. Most interestingly, the increase in small pulmonary vessel muscularization was prevented by training. Respective counterregulatory processes were detected for the nitric oxide-soluble guanylate cyclase-phosphodiesterase system. We conclude that individualized daily exercise can prevent vascular remodeling in hypoxia-induced PH.
Left ventricular sphericity index predicts systolic dysfunction in rats with experimental aortic regurgitation
Authors: Roscani Meliza Goi , Polegato Bertha Fulan , Minamoto Suzana Erico Tanni , Lousada Ana Paula Mena , Minicucci Marcos , Azevedo Paula , Matsubara Luiz Shiguero , Matsubara Beatriz Bojikian
Published: April 2014

Although an increased left ventricular (LV) diastolic diameter (DD) and a decreased ejection fraction have been used as markers for the surgical replacement of an insufficient aortic valve, these signals may be observed when irreversible myocardium damage has already occurred. The aim of this study was to determine whether change in LV geometry predicts systolic dysfunction in experimental aortic regurgitation. Male Wistar rats underwent surgical acute aorta regurgitation (aorta regurgitation group; n = 23) or a sham operation (sham group; n = 12). After the procedure, serial transthoracic echocardiograms were performed at 1, 4, 8, and 16 wk. At the end of protocol, the LV, lungs, and liver were dissected and weighed. During the follow-up, no animal developed overt heart failure. There was a correlation between the LV sphericity index and reduced fractional shortening ( P < 0.001) over time. A multiple regression model showed that the LVDD-sphericity index association at 8 wk was a better predictor of decreased fractional shortening at week 16 ( R2 = 0.50; P < 0.001) than was the LVDD alone ( R2 = 0.39; P = 0.001). LV geometry associated with increased LVDD improved the prediction of systolic dysfunction in experimental aortic regurgitation.
Development of Wood Apple Shell (Feronia acidissima) Powder Biosorbent and Its Application for the Removal of Cd(II) from Aqueous Solution
Authors: Suresh Ch. , Reddy D. Harikisore Kumar , Harinath Yapati , Naik B. Ramesh , Seshaiah K. , Reddy Annareddy V. Ramana
Published: April 2014

A biosorbent was prepared by using wood apple shell (WAS) powder and studied its application for the removal of Cd(II) from aqueous solution by a batch method. The biosorbent was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and elemental analysis. WAS is principally made up of lignin and cellulose, containing functional groups such as alcoholic, ketonic, and carboxylic groups which can be involved in complexation reactions with Cd(II). The effect of experimental parameters like initial pH, contact time, metal ion concentration, and sorbent dose on adsorption was investigated. The optimum pH for biosorption of Cd(II) onto WAS was found to be pH 5.0 and the quantitative removal of Cd(II) ions was achieved in 30 min. The kinetic study showed that the biosorption process followed the pseudo-second-order rate. Experimental data were analyzed by Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. Desorption studies were carried out using HCl solution.
Nonnegative Combined Matrices
Authors: Bru Rafael , Gassó Maria T. , Giménez Isabel , Santana Máximo
Published: April 2014

The combined matrix of a nonsingular real matrixAis the Hadamard (entrywise) productA∘A-1T. It is well known that row (column) sums of combined matrices are constant and equal to one. Recently, some results on combined matrices of different classes of matrices have been done. In this work, we study some classes of matrices such that their combined matrices are nonnegative and obtain the relation with the sign pattern ofA. In this case the combined matrix is doubly stochastic.
Developing a Chaotic-Simulation Based Model for Ranking High Selected Network Links in Hazardous Material Transportation
Authors: Mahmoudabadi Abbas
Published: April 2014

Hazardous material transportation is one of the main concerns due to the nature of hazardous materials and their incident impacts. In general, transport risk is a main attribute to develop mathematical models for hazardous material routing problem as well as network designing or improving road safety. This paper presents a chaotic-simulation based model to determine the high selected links to improve road network quality for hazardous material transportation, in which risk is considered as a chaotic variable over the network whereas a simulation technique has been applied to cover a wide range of selecting paths. A real road network, consists of fifty-nine nodes and eighty two-way edges, is used for running the mathematical model and checking validation. Due to the large amounts of hazardous material transported by trucks, the proposed methodology is focused on fuel transportation, and high selected list of edges (links) has been obtained to improve road safety. Sensitivity analysis revealed that using different seeds for generating transport risk has no significant effects on finding the most frequent paths and high selected edges.
Bifurcation of Nongeneric Homoclinic Orbit Accompanied by Pitchfork Bifurcation
Authors: Geng Fengjie , Li Song
Published: April 2014

The bifurcation of a nongeneric homoclinic orbit (i.e., the orbit comes from the equilibrium along the unstable manifold instead of the center manifold) connecting a nonhyperbolic equilibrium is investigated, and the nonhyperbolic equilibrium undergoes a pitchfork bifurcation. The existence (resp., nonexistence) of a homoclinic orbit and an 1-periodic orbit are established when the pitchfork bifurcation does not happen, while as the nonhyperbolic equilibrium undergoes a pitchfork bifurcation, we obtain the sufficient conditions for the existence of homoclinic orbit and two or three heteroclinic orbits, and so forth. Moreover, we explore the difference between the bifurcation of the nongeneric homoclinic orbit and the generic one.
Convergence Theorem for Equilibrium and Variational Inequality Problems and a Family of Infinitely Nonexpansive Mappings in Hilbert Space
Authors: Yinying Zhou , Jiantao Cao , Yali Wang
Published: April 2014

We introduce a hybrid iterative scheme for finding a common element of the set of common fixed points for a family of infinitely nonexpansive mappings, the set of solutions of the varitional inequality problem and the equilibrium problem in Hilbert space. Under suitable conditions, some strong convergence theorems are obtained. Our results improve and extend the corresponding results in (Chang et al. (2009), Min and Chang (2012), Plubtieng and Punpaeng (2007), S. Takahashi and W. Takahashi (2007), Tada and Takahashi (2007), Gang and Changsong (2009), Ying (2013), Y. Yao and J. C. Yao (2007), and Yong-Cho and Kang (2012)).
Motivational Processes in Online Learning: The Role of Tutorship for Laboratory Activities through the Semistructured Self-Evaluation Tests
Authors: Biasi Valeria , Domenici Gaetano
Published: April 2014

This contribution highlights the role of  affectiveprocesses in multimedia learning conducted by e-learning platform used in the General Psychology online laboratory activities, based on semistructured self-evaluation tests following the model proposed by Domenici (2005). These tests include items with a closed- and open-ended structure requiring the student to answer within space restrictions and, in some cases, within context simulations. This enables scorers to give generally univocal and objective scores thereby assuring high test validity and reliability. The focus is on the psychological aspects of the online tutor’s role and its effects on learning levels. Students who completed the online laboratory activities through the semistructured self-evaluation tests (n=252) obtained an average score of 27.7 in the objective examination; students who did not complete the activities or who never even started them (n=186) obtained an average score of 25.7. These differences are statistically significant (F1, 449=38.05;P<0.001). The advantages of online learning are highlighted: developing an active attitude towards learning, enabling the individualisation of learning, and strengthening motivation with regard to knowledge, self-assertiveness, and sociality. This motivational activation reinforces convergent and divergent cognitive skills, owing to the semistructured tests, which facilitate knowledge and study method acquisition.
Cross-Cultural Validity, Reliability, and Psychometric Properties of the Persian Version of the Scales for Outcomes in Parkinson’s Disease-Psychosocial Questionnaire
Authors: Fereshtehnejad Seyed-Mohammad , Farhadi Farzaneh , Hadizadeh Hasti , Shahidi Gholam Ali , Delbari Ahmad , Lökk Johan
Published: April 2014

Objectives. Considering the influence of different motor and nonmotor features of Parkinson’s disease (PD), it is important to evaluate the psychosocial functioning of the patients. For this purpose, the scales for outcomes in Parkinson’s disease-psychosocial questionnaire (SCOPA-PS) has been previously designed. The aim of our study was to assess the cross-cultural validation and psychometric properties of the Persian version of the SCOPA-PS.Methods. One hundred and ten nondemented idiopathic Parkinson’s disease (IPD) patients were consecutively recruited from an outpatient referral movement disorder clinic. Eligible patients filled up a number of questionnaires including the Persian version of SCOPA-PS during the face-to-face interview session and clinical examination to measure disease severity, nonmotor psychiatric symptoms, and health-related quality of life (HRQoL).Results. The highest and lowest correlation coefficients of internal consistency were reported for item 7 on “asking for help”(r=0.765)and item 5 on “sexual problems”(r=0.553). Cronbach’s alpha reliability coefficient of the entire scale was 0.87 (95% CI: 0.83–0.90). The Hoehn and Yahr stage(r=0.34, P<0.001), Schwab and England ADL scale(r=-0.55, P<0.001), anxiety(r=0.64, P<0.001), depression(r=0.71, P<0.001), and fatigue(r=0.35, P<0.001)were significantly correlated with the total score of the SCOPA-PS questionnaire.Conclusions. The Persian version of SCOPA-PS is a highly reliable and valid scale to measure psychosocial functioning in IPD patients with different sex, age-group, and educational level, which could be applied in future researches. Disease severity scales, depression, anxiety, fatigue, and different domains of HRQoL were all associated with psychosocial functioning in PD patients.
Acute and Chronic Fetal Anemia as a Result of Fetomaternal Hemorrhage
Authors: Singh Paul , Swanson Tara
Published: April 2014

Introduction.Fetomaternal hemorrhage represents a transfer of fetal blood to the maternal circulation. Although many etiologies have been described, most causes of fetomaternal hemorrhage remain unidentified. The differentiation between acute and chronic fetomaternal hemorrhage may be accomplished antenatally and may influence perinatal management.Case.A 36-year-old gravida 6 para 3 presented at 37 and 5/7 completed gestational weeks with ultrasound findings suggestive of chronic fetal anemia such as right ventricular enlargement, diminished cerebral vascular resistance, and elevated middle cerebral artery end-diastolic velocity. On the other hand, signs of acute fetal decompensation such as deterioration of the fetal heart tracing, diminished biophysical score, decreased cord pH, and increased cord base deficit were noted. Following delivery, the neonate’s initial hemoglobin was 4.0 g/dL and the maternal KB ratio was 0.015 indicative of a significant fetomaternal hemorrhage.Discussion.One should consider FMH as part of the differential diagnosis for fetal or immediate neonatal anemia. We describe a unique case of FMH that demonstrated both acute and chronic clinical features. It is our hope that this case will assist practitioners in differentiating acute FMH that may require emergent delivery from chronic FMH which may be able to be expectantly managed.
Visualization of Iron‐Binding Micelles in Acidic Recombinant Biomineralization Protein, MamC
Authors: Kashyap Sanjay , Woehl Taylor , Valverde-Tercedor Carmen , Sánchez-Quesada Miguel , Jiménez López Concepción , Prozorov Tanya
Published: April 2014

Biological macromolecules are utilized in low‐temperature synthetic methods to exert precise control over nanoparticle nucleation and placement. They enable low‐temperature formation of a variety of functional nanostructured materials with properties often not achieved via conventional synthetic techniques. Here we report on the in situ visualization of a novel acidic bacterial recombinant protein, MamC, commonly present in the magnetosome membrane of several magnetotactic bacteria, including Magnetococcus marinus, strain MC‐1. Our findings provide an insight into the self‐assembly of MamC and point to formation of the extended protein surface, which is assumed to play an important role in the formation of biotemplated inorganic nanoparticles. The self‐organization of MamC is compared to the behavior of another acidic recombinant iron‐binding protein, Mms6.
Determination of the DC Electrical Conductivity of Multiwalled Carbon Nanotube Films and Graphene Layers from Noncontact Time-Domain Terahertz Measurements
Authors: Dadrasnia E. , Lamela H. , Kuppam M. B. , Garet F. , Coutaz J.-L.
Published: April 2014

Measuring the DC conductivity of very thin films could be rather difficult because of the electrical contact issue. This DC conductivity can, however, be extracted from noncontact measurements at GHz and THz frequencies using elaborated conductivity models that nicely fit the experimental data. Here we employ this technique to study the DC conductivity of fragile nanometer-thick films of multiwalled carbon nanotubes and monolayer graphene. The THz response of the films is measured by THz time-domain spectroscopy. We show that the THz conductivity of the samples is well fitted by either Drude-Lorentz model or Drude-Smith model, giving information on the physics of electrical conductivity in these materials. This extraction procedure is validated by the good agreement between the so-obtained DC conductivity and the one measured with a classical 4-point probe in-line contact method.
Semi-G-Preinvexity and Optimality in Mathematical Programming
Authors: Peng Zai Yun , Zhao Yong , Yu Kai Zhi , Lin Zhi
Published: April 2014

We mainly discuss the properties and applications of semi-G-preinvexity, which was introduced in Peng and Chang 2013. Examples are given to show the existence of semi-G-preinvex functions. Three important properties and characterizations of semi-G-preinvex functions are established. Furthermore, under semi-G-preinvexity, some optimality results are obtained in nonlinear programming problems with inequality constraint. Our results improve and generalize some known results.
Constant Sign Solutions for Variable Exponent System Neumann Boundary Value Problems with Singular Coefficient
Authors: Wu Xianbin
Published: April 2014

We deal with the existence of constant sign solutions for the following variable exponent system Neumann boundary value problem:-div(|∇u|p(x)-2∇u)+λ|u|p(x)-2u=Fu(x,u,v) in Ω, -div(|∇v|q(x)-2∇v)+λ|v|q(x)-2v=Fv(x,u,v)inΩ, ∂u/∂γ=0=∂v/∂γ on ∂Ω. We give several sufficient conditions for the existence of the constant sign solutions, whenF(x,·,·)satisfies neither sub-(p(x),q(x)) growth condition, nor Ambrosetti-Rabinowitz condition (subcritical). In particular, we obtain the existence of eight constant sign solutions.
A Rule Based Feature Selection Approach for Target Classification in Wireless Sensor Networks with Sensitive Data Applications
Authors: Hao Zhiyong , Liu Bin
Published: April 2014

One of the important issues faced in the domain of target classification in wireless sensor networks is the restricted lifetime of individual sensors, caused by limited battery capacity. Although the base station usually has sufficient energy supply and computational power, it is often deemed to be the object of enemy invading hostile terrain. Hence, minimizing energy consumption of sensors while maintaining a given classification accuracy is a key problem in this research area, especially for sensitive data applications. This paper proposes a rule based feature selection approach rather than all-features approach that aims at increasing the energy efficiency of the system without losing much classification accuracy. In experiments, the feasibility and effectiveness of our approach are demonstrated empirically.
Throughput-Delay Trade-Off for Cognitive Radio Networks: A Convex Optimization Perspective
Authors: Hu Hang , Zhang Hang , Yu Hong
Published: April 2014

The throughput-delay trade-off problem for cooperative spectrum sensing (CSS) is investigated. It is proved that the maximum achievable throughput and the minimum transmission delay cannot be obtained simultaneously. An efficient algorithm is proposed to optimize the sensing bandwidth and the final decision threshold jointly such that the throughput is maximized while the delay is constrained. It is demonstrated that convex optimization plays an essential role in solving the problem in an efficient way. Simulation results show that the proposed optimal scheme can significantly improve the throughput of the secondary users (SUs) under the constraint that the delay Quality of Service (QoS) requirements of the SUs are satisfied.
An Efficient Index Building Algorithm for Selection of Aggregator Nodes in Wireless Sensor Networks
Authors: Ihm Sun-Young , Nasridinov Aziz , Park Young-Ho
Published: April 2014

In wireless sensor networks (WSNs), aggregator nodes perform the data aggregation process. Thus, careful selection of the aggregator nodes is needed to reduce network traffic in data aggregation process and prolong overall lifetime of the network. In this paper, we formulate selection process of the aggregator nodes as a top- k query problem. To answer the top- k queries efficiently in the large-scale WSNs, building and using the indexes are important. Thus, we propose an efficient index building algorithm for selection of aggregator nodes, called the Approximate Convex Hull Index (simply, aCH-Index). The main idea of our approach is to construct a convex hull over the sensor nodes in the WSNs, which enables speeding up the extraction of a set of sensor nodes that are potential candidates to become an aggregator node. In order to do so, the aCH-Index computes the skyline over the entire set of the sensor nodes, partitions the region into multiple subregions to reduce the computing time of convex hull in all origins, and then computes the convex hull in each subregion. Through the experiments with synthetic data, we show that aCH-Index outperforms the existing methods.
Robust Synchronization of Hyperchaotic Systems with Uncertainties and External Disturbances
Authors: Wang Qing , Yu Yongguang , Wang Hu
Published: April 2014

The robust synchronization of hyperchaotic systems with uncertainties and external disturbances is investigated. Based on the Lyapunov stability theory, the appropriate adaptive controllers and parameter update laws are designed to achieve the synchronization of uncertain hyperchaotic systems. The robust synchronization of two hyperchaotic Chen systems is taken as an example to verify the feasibility of the presented schemes. The size of the subcontroller gain’s influences on the convergence speed is discussed. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed synchronization schemes.
Ultimate Capacity Analysis and Determination of the Position of Failure Surface for Uplift Piles
Authors: Su Qian , Zhang Xiaoxi , Yin Pingbao , Zhao Wenhui
Published: April 2014

Ultimate capacity and failure surface position of uplift piles are dependent on soil parameters. In this paper, the horizontal slice method is used to discuss the relation among the ultimate uplift capacity, the failure surface position, and soil parameters with Mohr‐Coulomb failure criterion. According to the limit equilibrium analysis, the ultimate uplift capacity is calculated by dividing soil around the pile into slices with considering the potential failure surface as a group of several sectional planes. Then the multivariate function used to calculate ultimate capacity is established and optimized by the sequential quadratic programming. Through the numerical calculation and comparison with the previous research, the results show that the method is reasonable and effective and can be used to determine the failure surface and the magnitude of the ultimate capacity of uplift piles.
On Approximate Solutions of Functional Equations in Vector Lattices
Authors: Batko Bogdan
Published: April 2014

We provide a method of approximation of approximate solutions of functional equations in the class of functions acting into a Riesz space (algebra). The main aim of the paper is to provide a general theorem that can act as a tool applicable to a possibly wide class of functional equations. The idea is based on the use of the Spectral Representation Theory for Riesz spaces. The main result will be applied to prove the stability of an alternative Cauchy functional equationF(x+y)+F(x)+F(y)≠0⇒F(x+y)=F(x)+F(y)in Riesz spaces, the Cauchy equation with squaresF(x+y)2=(F(x)+F(y))2inf-algebras, and the quadratic functional equationF(x+y)+F(x-y)=2F(x)+2F(y)in Riesz spaces.
Modeling and Characteristic Study of Thin Film Based Biosensor Based on COMSOL
Authors: Su Yang
Published: April 2014

The model of thin film based biosensor is built based on COMSOL in order to simulate and optimize the electronic characteristic of dipolar electrodes system and tetrapolar electrodes system. Zones of negative sensitivity exist between current carrying electrodes and voltage measuring electrodes while the polarization occurs at the edges of electrodes. By changing the parameters embracing distance between electrodes, thickness of electrodes, and the width of inner electrodes (for tetrapolar electrodes system only), the polarization and zones of negative sensitivity can be receded to some extent, which improves the system’s performance. Tetrapolar electrodes system has less polarization but more negative‐sensitivity zones compared to dipolar electrodes system and different setups response differently to these changing parameters.
Global Hopf Bifurcation on Two-Delays Leslie-Gower Predator-Prey System with a Prey Refuge
Authors: Liu Qingsong , Lin Yiping , Cao Jingnan
Published: April 2014

A modified Leslie-Gower predator-prey system with two delays is investigated. By choosingτ1andτ2as bifurcation parameters, we show that the Hopf bifurcations occur when time delay crosses some critical values. Moreover, we derive the equation describing the flow on the center manifold; then we give the formula for determining the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions. Numerical simulations are carried out to illustrate the theoretical results and chaotic behaviors are observed. Finally, using a global Hopf bifurcation theorem for functional differential equations, we show the global existence of the periodic solutions.
Antibacterial Activity of a Chitosan-PVA-Ag+-Tobermorite Composite for Periodontal Repair
Authors: Hurt Andrew P. , Ruiz de Clavijo Alejandra A. , Vine George J. , Coleman Aimee A. , Coleman Nichola J.
Published: April 2014

A polymer-mineral composite was prepared by solvent casting a mixture of chitosan, poly(vinyl alcohol), and Ag+-exchanged tobermorite in dilute acetic acid and characterised by scanning electron microscopy and Fourier transform infrared spectroscopy. The in vitro bioactivity of the CPTAg membrane was confirmed by the formation of hydroxyapatite on its surface in simulated body fluid. The alkaline dissolution products of the tobermorite lattice buffered the acidic breakdown products of the chitosan polymer and the presence of silver ions resulted in marked antimicrobial action against S. aureus, P. aeruginosa, and E. coli. The in vitro cytocompatibility of the CPTAg membrane was confirmed using MG63 osteosarcoma cells. The findings of this preliminary study have indicated that chitosan-poly(vinyl alcohol)-Ag+-tobermorite composites may be suitable materials for guided tissue regeneration applications.
Application of Microsatellite Markers in Conservation Genetics and Fisheries Management: Recent Advances in Population Structure Analysis and Conservation Strategies
Authors: Abdul-Muneer P. M.
Published: April 2014

Microsatellites are the most popular and versatile genetic marker with myriads of applications in population genetics, conservation biology, and evolutionary biology. These are the arrays of DNA sequences, consisting of tandemly repeating mono-, di-, tri-, and tetranucleotide units, which are distributed throughout the genomes of most eukaryotic species. Microsatellites are codominant in nature, highly polymorphic, easily typed, and Mendelian inherited, all properties which make them very suitable for the study of population structure and pedigree analysis and capable of detecting differences among closely related species. PCR for microsatellites can be automated for identifying simple sequence repeat polymorphism. Small amount of blood samples or alcohol preserved tissue is adequate for analyzing them. Most of the microsatellites are noncoding, and therefore variations are independent of natural selection. These properties make microsatellites ideal genetic markers for conservation genetics and fisheries management. This review addresses the applications of microsatellite markers in conservation genetics and recent advances in population structure analysis in the context of fisheries management.
Retinal-Image Quality and Night-Vision Performance after Alcohol Consumption
Authors: Castro José J. , Pozo Antonio M. , Rubiño Manuel , Anera Rosario G. , Jiménez del Barco Luis
Published: April 2014

Purpose.To evaluate the influence of alcohol consumption on the retinal-image quality and visual performance under surrounding low-illumination conditions.Methods.A volunteer sample of 67 subjects was analyzed. Optical quality of the eye was evaluated by means of the Strehl ratio, the Objective Scattering Index (OSI), and the tear-film quality. We used the visual disturbance index (VDI) to evaluate visual performance under low-illumination conditions and we measured the pupil size under these conditions. The tear-film volume was also measured. All measurements were made before and after alcohol consumption and patients were classified into two groups depending on their breath alcohol content (BrAC): low-alcohol (BrAC < 0.25 mg/L) and high-alcohol content (BrAC ≥ 0.25 mg/L).Results.The VDI was significantly higher after alcohol consumption: the higher the BrAC, the higher the deterioration of the visual discrimination capacity. The pupil size increased significantly for the high-BrAC group. Parameters evaluating optical quality deteriorated after alcohol consumption.Conclusion.The visual performance under low-illumination conditions and the retinal-image quality were deteriorated after alcohol consumption, especially for the high-alcohol group. Furthermore, some physiological changes were observed under effects for high-alcohol contents, such as an increase in the pupil size and disturbances in the tear film, which deteriorated optical quality.
Global Existence and Energy Decay Rates for a Kirchhoff-Type Wave Equation with Nonlinear Dissipation
Authors: Kim Daewook , Kim Dojin , Hong Keum-Shik , Jung Il Hyo
Published: April 2014

The first objective of this paper is to prove the existence and uniqueness of global solutions for a Kirchhoff-type wave equation with nonlinear dissipation of the form under suitable assumptions on . Next, we derive decay estimates of the energy under some growth conditions on the nonlinear dissipationg. Lastly, numerical simulations in order to verify the analytical results are given.
Robust Switching Control Strategy for a Transmission System with Unknown Backlash
Authors: Ling Qiang , Yan Zhe , Shen Honghai , Li Jiquan , Wang Yongyang
Published: April 2014

This paper proposes a robust switching control strategy for a transmission system with unknown backlash. Firstly, the adverse effects of backlash nonlinearity in the transmission system are analyzed. Then the backlash model and different operating modes of the transmission system with backlash are investigated. For each operating mode, an individual controller is designed to make the system robust against the unknown backlash and various frequencies of the input signal. Moreover, a supervisory controller is proposed to estimate the current mode of the transmission system and coordinate the controller switching between different modes. Simulations are done to verify that our switching control strategy can efficiently reduce the oscillation caused by backlash and is quite robust against the variation of the frequency of the input signal.
Antioxidant Strategies and Respiratory Disease of the Preterm Newborn: An Update
Authors: Poggi Chiara , Dani Carlo
Published: April 2014

Preterm newborns are challenged by an excessive oxidative burden, as a result of several perinatal stimuli, as intrauterine infections, resuscitation, mechanical ventilation, and postnatal complications, in the presence of immature antioxidant capacities. “Oxygen radical disease of neonatology” comprises a wide range of conditions sharing a common pathway of pathogenesis and includes bronchopulmonary dysplasia (BPD) and other main complications of prematurity. Antioxidant strategies may be beneficial in the prevention and treatment of oxidative stress- (OS-) related lung disease of the preterm newborn. Endotracheal supplementation or lung-targeted overexpression of superoxide dismutase was proved to reduce lung damage in several models; however, the supplementation in preterm newborn failed to reduce the risk of BPD, although long-term respiratory outcomes were improved. Also melatonin administration to small cohorts of preterm newborns suggested beneficial effects on lung OS. The possibility to identify single nucleotide polymorphism affecting the risk of BPD may help to identify specific populations with particularly high risk of OS-related diseases and may pose the basis for individually targeted treatments. Finally, surfactant replacement may lead to local anti-inflammatory and antioxidant effects, thanks to specific enzymatic and nonenzymatic antioxidants naturally present in animal surfactants.
The Potential Roles of Bisphenol A (BPA) Pathogenesis in Autoimmunity
Authors: Kharrazian Datis
Published: April 2014

Bisphenol A (BPA) is a monomer found in commonly used consumer plastic goods. Although much attention in recent years has been placed on BPA’s impact as an endocrine disruptor, it also appears to activate many immune pathways involved in both autoimmune disease development and autoimmune reactivity provocation. The current scientific literature is void of research papers linking BPA directly to human or animal onset of autoimmunity. This paper explores the impact of BPA on immune reactivity and the potential roles these mechanisms may have on the development or provocation of autoimmune diseases. Potential mechanisms by which BPA may be a contributing risk factor to autoimmune disease development and progression include its impact on hyperprolactinemia, estrogenic immune signaling, cytochrome P450 enzyme disruption, immune signal transduction pathway alteration, cytokine polarization, aryl hydrocarbon activation of Th-17 receptors, molecular mimicry, macrophage activation, lipopolysaccharide activation, and immunoglobulin pathophysiology. In this paper a review of these known autoimmune triggering mechanisms will be correlated with BPA exposure, thereby suggesting that BPA has a role in the pathogenesis of autoimmunity.