bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of cardiac time intervals between echocardiography and impedance cardiography at various heart rates
Authors: van Eijnatten Maureen A.J.M. , van Rijssel Michael J. , Peters Rob J.A. , Verdaasdonk Rudolf M. , Meijer Jan H. 
Published: April 2014

Abstract
The non-invasively measured initial systolic time interval (ISTI) reflects a time difference between the electrical and pumping activity of the heart and depends on cardiac preload, afterload, autonomic nervous control and training level. However, the duration of the ISTI has not yet been compared to other time markers of the heart cycle. The present study gauges the duration of the ISTI by comparing the end point of this interval, the C-point, with heart cycle markers obtained by echocardiography. The heart rate of 16 healthy subjects was varied by means of an exercise stimulus. It was found that the C-point, and therefore the end point of ISTI, occurred around the moment of the maximum diameter of the aortic arch in all subjects and at all heart rates. However, while the time difference between the opening of the aortic valves and the maximum diameter of the aortic arch decreased significantly with decreasing RR-interval, the time difference with respect to the moment of the C-point remained constant within the subjects. This means that the shortening of the ISTI with increasing heart rate in response to an exercise stimulus was caused by a shortening of the pre-ejection period (PEP). It is concluded that the ISTI can be used as a non-invasive parameter indicating the time difference between the electrical and mechanical pumping activity of the heart, both inside and outside the clinic.
Simplified estimation of membrane potentials induced by high-frequency electric signals
Authors: Saviz Mehrdad , Faraji-Dana Reza 
Published: April 2014

Abstract
In this paper we show why the poorly conducting cytoplasmic membranes have little effect on the overall impedance of the tissue above a certain frequency, and derive an estimate of this upper frequency. It is further shown that the induced transmembrane potentials at different sites over the membrane can be found through a simple formula for frequencies above the threshold, without the need to analytically or theoretically model the membranes directly. The findings are validated for an irregular cell shape through rigorous numerical modeling.
Parenteral Nutrition-Associated Liver Disease: a Retrospective Study of Ursodeoxycholic Acid Use in Neonates
Authors: Thibault Maxime , McMahon Jessica , Faubert Guillaume , Charbonneau Julie , Malo Josianne , Ferreira Ema , Mohamed Ibrahim 
Published: April 2014

OBJECTIVESTo verify the effect of ursodeoxycholic acid (UDCA) on the duration of neonatal parenteral nutrition-associated liver disease.METHODSRetrospective cohort study of neonates in intensive care between 2004 and 2007 presenting with parenteral nutrition-associated liver disease.RESULTSOf 118 eligible infants, 64 received UDCA. Cholestasis lasted longer in the UDCA group (79 vs. 50 days, p=0.001). However, treatment was delayed for a median of 24 days after cholestasis onset. Multivariate Cox regression analysis showed no association between UDCA and cholestasis duration. The rate of decline of conjugated bilirubin was greater in treated patients (median 0.084 mg/dL/day vs. 0.60 mg/dL/day; p=0.009) and weight gain was greater (22.8 vs. 17.7 g/kg/day, p=0.010).CONCLUSIONSUDCA therapy was not associated with the duration of parenteral nutrition-associated liver disease. A delay in treatment initiation might explain this result. UDCA therapy was associated with a faster decline of conjugated bilirubin and greater weight gain.
Diodes, Fundamentals and Transport Theory
Authors: Misiakos Konstantinos 
Published: April 2014

Abstract
The following article is a brief overview of the device physics of the semiconductor p‐n junction diode. It reviews the basic transport equations and derives analytical expressions for the steady state and transient current‐voltage characteristics. The range of validity of the basic equations and the analytical expressions is outlined. Special emphasis is placed upon the small signal analysis and impedance spectroscopy based on equivalent circuit models. The equations derived are compared against experimental results on silicon diodes at room as well as at low temperatures. In addition to conventional diodes, non‐conventional devices based on tunneling are also considered.
Mixing state of regionally transported soot particles and the coating effect on their size and shape at a mountain site in Japan
Authors: Adachi Kouji , Zaizen Yuji , Kajino Mizuo , Igarashi Yasuhito 
Published: April 2014

AbstractSoot particles influence the global climate through interactions with sunlight. A coating on soot particles increases their light absorption by increasing their absorption cross section and cloud condensation nuclei activity when mixed with other hygroscopic aerosol components. Therefore, it is important to understand how soot internally mixes with other materials to accurately simulate its effects in climate models. In this study, we used a transmission electron microscope (TEM) with an auto particle analysis system, which enables more particles to be analyzed than a conventional TEM. Using the TEM, soot particle size and shape (shape factor) were determined with and without coating from samples collected at a remote mountain site in Japan. The results indicate that ~10% of aerosol particles between 60 and 350 nm in aerodynamic diameters contain or consist of soot particles and ~75% of soot particles were internally mixed with nonvolatile ammonium sulfate or other materials. In contrast to an assumption that coatings change soot shape, both internally and externally mixed soot particles had similar shape and size distributions. Larger aerosol particles had higher soot mixing ratios, i.e., more than 40% of aerosol particles with diameters >1 µm had soot inclusions, whereas <20% of aerosol particles with diameters <1 µm included soot. Our results suggest that climate models may use the same size distributions and shapes for both internally and externally mixed soot; however, changing the soot mixing ratios in the different aerosol size bins is necessary.
Cloud fraction mediates the aerosol optical depth‐cloud top height relationship
Authors: Gryspeerdt E. , Stier P. , Grandey B. S. 
Published: April 2014

AbstractThe observed strong link between aerosol optical depth (τ) and cloud top pressure (ptop) has frequently been interpreted as the invigoration of convective clouds by aerosol, with increased τ being strongly correlated with decreases in ptop (increases in cloud top height). A strong correlation between τ and cloud fraction (fc) has also been observed. Using satellite‐retrieved data, here we show that ptop is also strongly correlated to fc, and when combined with the strong sensitivity between fc and τ, a large proportion of the relationship between ptop and τcan be reconstructed. Given the uncertainties about the influence of aerosol‐cloud interactions on the τ‐fc relationship, this suggests that a large fraction of the τ‐ptop correlation may not be due to aerosol effects. Influences such as aerosol humidification and meteorology play an important role and should therefore be considered in studies of aerosol‐cloud interactions.
Effects of Two Physiotherapy Booster Sessions on Outcomes With Home Exercise in People With Knee Osteoarthritis: A Randomized Controlled Trial
Authors: Bennell Kim L. , Kyriakides Mary , Hodges Paul W. , Hinman Rana S. 
Published: April 2014

ObjectiveEnhancing exercise adherence over the longer term is an important goal in self‐management of knee osteoarthritis (OA). Following an initial period of more intensive exercise supervision, this study investigated whether 2 additional physiotherapy visits improved outcomes with continued home exercise over a subsequent 24‐week period.MethodsA total of 78 people with medial knee OA (mean ± SD age 62.1 ± 6.9 years, mean ± SD body mass index 29.4 ± 4.0 kg/m2, and radiographic disease severity 19% mild, 49% moderate, and 32% severe) who completed a 12‐week physiotherapist‐supervised exercise trial were randomly allocated to 2 30‐minute physiotherapy booster sessions (delivered by 8 physiotherapists in private clinics) or no booster sessions for the subsequent 24 weeks. All participants were asked to continue home exercises 4 times weekly. Primary outcomes were change in pain, using a 100‐mm visual analog scale, and self‐reported physical function, measured using the Western Ontario McMaster Universities Osteoarthritis Index. Participants and physiotherapists were unblinded to group allocation, although participants were blinded to the study hypothesis.ResultsA total of 74 participants (95%) completed the trial. There was no significant difference between groups for change in pain (mean difference [95% confidence interval (95% CI)] 0.7 mm [−9.4, 8.0]; P = 0.88) or physical function (−0.3 units [95% CI −4.0, 3.5]; P = 0.88). The mean ± SD percentage of home exercise sessions completed was 56% ± 34% in the booster group and 51% ± 37% in the control group (P > 0.05).ConclusionTwo booster sessions with a physiotherapist did not influence pain or physical function outcomes, or measures of home exercise adherence. These findings suggest other more effective strategies are needed to maximize longer‐term adherence with the aim to achieve greater improvements in clinical outcomes from exercise in this patient population.
Socioeconomic Disparities in the Health of African Americans With Rheumatoid Arthritis From the Southeastern United States
Authors: Baldassari Antoine R. , Cleveland Rebecca J. , Jonas Beth L. , Conn Doyt L. , Moreland Larry W. , Bridges S. Louis , Callahan Leigh F. 
Published: April 2014

ObjectiveTo examine cross‐sectional baseline data from the Consortium for the Longitudinal Evaluation of African Americans with Early Rheumatoid Arthritis registry for the association between socioeconomic status (SES) with clinical and self‐report health outcomes.MethodsWe analyzed data on 937 African Americans who provided comprehensive sociodemographic data in addition to self‐reported health outcomes. SES measures included educational attainment, homeownership, household income, and occupation. Outcomes included measures of disease activity, joint damage, autoantibody status, and self‐reported measures. Multivariable linear, logistic, and zero‐inflated Poisson regression models were used to estimate associations of each SES measure with rheumatoid arthritis (RA) outcomes, controlling for sex, age, disease duration, comorbid conditions, body mass index, smoking, methotrexate/leflunomide use, and biologic agent use.ResultsThe mean age was 54 years, 86% were women, and the mean RA disease duration was 7.8 years. Approximately 24% had less than a high school degree, 56% had a nonprofessional occupation, 75% had a household income ≤$30,000, and 55% were nonhomeowners. In multivariable regression models, significantly increased associations of disease activity measures and self‐reported health outcomes were observed with low household income (≤$30,000/year) and nonhomeownership. Education less than high school was primarily associated with self‐reported health outcomes. Among participants with disease duration <2 years, associations of SES were confined to self‐reported measures.ConclusionOur results indicate significant socioeconomic disparities in self‐reported physical and mental health, clinical disease activity measures, and autoantibody status among African Americans with RA not explained by differences in demographics, medication use, and health behaviors.
Risk Factors for Juvenile Dermatomyositis: Exposure to Tobacco and Air Pollutants During Pregnancy
Authors: Orione Maria Angélica M. , Silva Clovis A. , Sallum Adriana M. E. , Campos Lúcia M. A. , Omori Clarissa H. , Braga Alfésio L. F. , Farhat Sylvia C. L. 
Published: April 2014

ObjectiveTo evaluate the influence of exposure to inhaled environmental factors during pregnancy on the diagnosis of juvenile dermatomyositis (DM).MethodsWe performed a case–control study comprising 20 juvenile DM patients and 56 healthy controls matched by age and sex who were residents in the metropolitan region of a large city. A questionnaire assessed demographic data and environmental inhalation exposure during pregnancy (occupational exposure to demolition, chalk, construction and/or quarry dust, paints, varnish, gasoline vapor, and/or battery fluids; stationary sources of inhaled pollution near the mother's home; and maternal tobacco exposure). Daily concentrations of inhaled particulate matter, SO2, NO2, O3, and carbon monoxide (CO) were evaluated throughout the gestational period.ResultsMaternal occupational exposure to school chalk dust/gasoline vapor in the juvenile DM group was significantly higher compared with controls (50% versus 4.6%; P = 0.001). Smoking mothers and secondhand smoke exposure at home during pregnancy were significantly higher in the juvenile DM group versus controls (smoking mothers: 20% versus 1.7%; P = 0.01, and secondhand smoke: 35% versus 19%; P = 0.07). In univariate logistic regression models, maternal smoking, occupational exposure to inhaled agents, and the highest tertile of tropospheric CO (3.2–5.4 parts per million) in the third trimester were significantly associated with juvenile DM (P ≤ 0.05). In the multivariate analysis, smoking mother (odds ratio [OR] 13.26 [95% confidence interval (95% CI) 1.21–144.29], P = 0.03), occupational exposure (OR 35.39 [95% CI 1.97–632.80], P = 0.01), and CO (third tertile) exposure in the third trimester of gestation (OR 12.21 [95% CI 1.28–115.96], P = 0.03) remained risk factors for juvenile DM.ConclusionInhaled pollutants and tobacco smoking during fetal development may contribute to juvenile DM.
Adsorption Parameters Studies for the Removal of Mercury from Aqueous Solutions Using Hybrid Sorbent
Authors: Salahi Soheila , Ghorbani Mohsen 
Published: April 2014

ABSTRACTThe aim of this research work is to investigate adsorption of mercury ions from an aqueous solution on a biocompatible polymeric polypyrrole‐chitosan (PPy/CTN) nanocomposite. The PPy/CTN nanocomposite was prepared in aqueous media by chemical polymerization of pyrrole in the presence of ferric chloride as an oxidant. Langmuir, Freundlich, and Temkin adsorption isotherms were applicable to the adsorption process, and their constants were evaluated. The thermodynamic equilibrium constant and the Gibbs free energy were determined. Results indicated that the Langmuir model gave a better fit to the experimental data than the other two equations. The adsorption capacity (qmax) of PPy/CTN for Hg(II) ions in terms of monolayer adsorption was 40 mg/g. The negative value of Gibbs free energy (ΔGo) indicates feasible and spontaneous adsorption of Hg(II) on the PPy/CTN nanocomposite. Also the change in entropy (ΔSo) and enthalpy (ΔHo) were estimated to be –0.21 KJ (mol K)−1 and –18.183 kJ mol−1, respectively.
Remarkable Enhancement of the Rate of the Intramolecular Morita–Baylis–Hillman Reaction by the Combination of a Nucleophilic Catalyst and 1,3‐Diphenyl‐2‐thiourea
Authors: Mandai Hiroki , Shimowaki Keita , Mitsudo Koichi , Suga Seiji 
Published: April 2014

AbstractThe rate of the intramolecular Morita‐Baylis–Hillman (MBH) reaction is remarkably enhanced by the combination of catalytic amounts of a nucleophilic catalyst (4‐dimethylaminopyridine (DMAP), 4‐pyrrolidinopyridine (PPY), or PBu3) and 1,3‐diphenyl‐2‐thiourea, and the desired MBH adducts are obtained in good to high yields within a few hours.
Phosphine‐Initiated General‐Base‐Catalyzed Quinolone Synthesis
Authors: Khong San , Kwon Ohyun 
Published: April 2014

AbstractPhosphinocatalysis provides a new approach toward 3‐substituted‐4‐quinolones. A simple procedure, which uses Ph3P as an inexpensive catalyst and S‐phenyl 2‐(N‐tosylamido)benzothioates and activated alkynes as starting materials, provides direct access to several 3‐aroyl‐4‐quinolones and methyl 4‐quinolone‐3‐carboxylate esters. The reaction presumably occurs through general base catalysis, with the initial addition of Ph3P to the activated alkyne generating the phosphonium enoate zwitterion, which acts as the strong base that initiates the reaction.
Heterolytic Cleavage of Hydrogen by an Iron Hydrogenase Model: An Fe‐H⋅⋅⋅H‐N Dihydrogen Bond Characterized by Neutron Diffraction
Authors: Liu Tianbiao , Wang Xiaoping , Hoffmann Christina , DuBois Daniel L. , Bullock R. Morris 
Published: April 2014

AbstractHydrogenase enzymes in nature use hydrogen as a fuel, but the heterolytic cleavage of HH bonds cannot be readily observed in enzymes. Here we show that an iron complex with pendant amines in the diphosphine ligand cleaves hydrogen heterolytically. The product has a strong Fe‐H⋅⋅⋅H‐N dihydrogen bond. The structure was determined by single‐crystal neutron diffraction, and has a remarkably short H⋅⋅⋅H distance of 1.489(10) Å between the protic N‐Hδ+ and hydridic Fe‐Hδ− part. The structural data for [CpFeH(PtBu2NtBu2H)]+ provide a glimpse of how the HH bond is oxidized or generated in hydrogenase enzymes. These results now provide a full picture for the first time, illustrating structures and reactivity of the dihydrogen complex and the product of the heterolytic cleavage of H2 in a functional model of the active site of the [FeFe] hydrogenase enzyme.
Polymeric Schiff Bases as Low‐Voltage Redox Centers for Sodium‐Ion Batteries
Authors: Castillo‐Martínez Elizabeth , Carretero‐González Javier , Armand Michel 
Published: April 2014

AbstractThe redox entity comprising two Schiff base groups attached to a phenyl ring (NCHArHCN) is reported to be active for sodium‐ion storage (Ar=aromatic group). Electroactive polymeric Schiff bases were produced by reaction between non‐conjugated aliphatic or conjugated aromatic diamine block with terephthalaldehyde unit. Crystalline polymeric Schiff bases are able to electrochemically store more than one sodium atom per azomethine group at potentials between 0 and 1.5 V versus Na+/Na. The redox potential can be tuned through conjugation of the polymeric chain and by electron injection from donor substituents in the aromatic rings. Reversible capacities of up to 350 mA h g−1 are achieved when the carbon mixture is optimized with Ketjen Black. Interestingly, the “reverse” configuration (CHNArNHC) is not electrochemically active, though isoelectronic.
Coordination Adducts of Niobium(V) and Tantalum(V) Azide M(N3)5 (M=Nb, Ta) with Nitrogen Donor Ligands and their Self‐Ionization
Authors: Haiges Ralf , Deokar Piyush , Christe Karl O. 
Published: April 2014

AbstractSeveral new donor–acceptor adducts of niobium and tantalum pentaazide with N‐donor ligands have been prepared from the pentafluorides by fluoride–azide exchange with Me3SiN3 in the presence of the corresponding donor ligand. With 2,2′‐bipyridine and 1,10‐phenanthroline, the self‐ionization products [MF4(2,2′‐bipy)2]+[M(N3)6]−, [M(N3)4(2,2′‐bipy)2]+[M(N3)6]− and [M(N3)4(1,10‐phen)2]+[M(N3)6]− were obtained. With the donor ligands 3,3′‐bipyridine and 4,4′‐bipyridine the neutral pentaazide adducts (M(N3)5)2⋅L (M=Nb, Ta; L=3,3′‐bipy, 4,4′‐bipy) were formed.
Highly Diastereo‐ and Enantioselective Silver‐Catalyzed Double [3+2] Cyclization of α‐Imino Esters with Isocyanoacetate
Authors: Shao Pan‐Lin , Liao Jia‐Yu , Ho Yee Ann , Zhao Yu 
Published: April 2014

AbstractPresented herein is a new complexity‐generating method in which both functionalities of α‐imino esters undergo stereoselective cyclization with isocyanoacetates to produce directly linked oxazole‐imidazolines, which can be transformed into highly functionalized α,β‐diamino esters and imidazolinium salts in high diastereo‐ and enantiopurity.
Gold‐Catalyzed 1,2‐Oxoarylations of Nitriles with Pyridine‐Derived Oxides
Authors: Karad Somnath Narayan , Liu Rai‐Shung 
Published: April 2014

AbstractWe report the first success in the gold‐catalyzed oxoarylations of nitriles with pyridine‐derived N‐oxides using gold carbenes as initiators. These oxoarylations were also achieved satisfactorily in intermolecular three‐component oxidations, including diverse alkenyldiazo esters, nitriles, and pyridine‐based oxides.
Remote Enantioselective Friedel–Crafts Alkylations of Furans through HOMO Activation
Authors: Li Jun‐Long , Yue Cai‐Zhen , Chen Peng‐Qiao , Xiao You‐Cai , Chen Ying‐Chun 
Published: April 2014

AbstractCatalytic asymmetric Friedel–Crafts alkylation is a powerful protocol for constructing a chiral C(sp2)C(sp3) bond. Most previous examples rely on LUMO activation of the electrophiles using chiral catalysts with subsequent attack by electron‐rich arenes. Presented herein is an alternative strategy in which the HOMO of the aromatic π system of 2‐furfuryl ketones is raised through the formation of a formal trienamine species using a chiral primary amine. Exclusive regioselective alkylation at the 5‐position occurred with alkylidenemalononitriles, and high reactivity and excellent enantioselectivity (up to 95 % ee) was obtained by this remote activation.
Pattern‐Based Detection of Toxic Metals in Surface Water with DNA Polyfluorophores
Authors: Yuen Lik Hang , Franzini Raphael M. , Wang Shenliang , Crisalli Pete , Singh Vijay , Jiang Wei , Kool Eric T. 
Published: April 2014

AbstractHeavy metal contamination of water can be toxic to humans and wildlife; thus the development of methods to detect this contamination is of high importance. Here we describe the design and application of DNA‐based fluorescent chemosensors on microbeads to differentiate eight toxic metal ions in water. We developed and synthesized four fluorescent 2′‐deoxyribosides of metal‐binding ligands. A tetramer‐length oligodeoxy‐fluoroside (ODF) library of 6561 members was constructed and screened for sequences responsive to metal ions, of which seven sequences were selected. Statistical analysis of the response patterns showed successful differentiation of the analytes at concentrations as low as 100 nM. Sensors were able to classify water samples from 13 varied sites and quantify metal contamination in unknown specimens. The results demonstrate the practical potential of bead‐based ODF chemosensors to analyze heavy metal contamination in water samples by a simple and inexpensive optical method.
Artificial liver support systems: a patient‐device model
Authors: Annesni Maria Cristina , Piemonte Vincenzo , Turchetti Luca 
Published: April 2014

ABSTRACTMany efforts have been carried out for over 40 years in the attempt to design liver support devices suitable for a temporary clinical use, either to bridge the patients to liver transplantation or to help to keep them alive until the recovery of native liver function. Really, a deeper knowledge of the physicochemical basis of their functioning is essential to ‘engineer’ these devices, that is, to design new artificial liver devices, to optimize the existing ones and to taylor the patient treatment on his clinical state. In this framework, this work has been finalized to obtain a mathematical model of the whole patient‐artificial device system as useful tool for a chemical engineering point of view analysis. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.