bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient giant R waves in the early phase of acute myocardial infarction: Association with ventricular fibrillation
Authors: Madias J. E. , Krikelis E. N.
Published: January 2015

An unusual electrocardiographic (ECG) pattern was observed in five patients who suffered an acute anterior myocardial infarction. Early in their illness and following resuscitation from ventricular fibrillation (three patients), in the midst of recurrent ventricular irritability prior to development of ventricular fibrillation (one patient), and following a period of seizures (one patient), the ECG showed ST‐segment elevation, marked increase in the R‐wave amplitude, disappearance of S waves and merging of QRS complexes with the elevated ST segments. ECG patterns noted in these patients were similar to the ones recorded from dogs immediately after ligation of a large coronary artery, and from patients with severe episodes of variant angina. Although these early electrocardiographic changes probably reflect either marked regional transmural blood flow deprivation or its aftermath, they could not be taken as indices of eventual massive myocardial necrosis since in most of these patients the alterations were followed by development of nontransmural myocardial infarction. The possible mechanisms and the implications of such discrepancy between early and late electrocardiographic indicators of injury or necrosis is discussed.
Simultaneous contrast imaging of the left ventricle by two‐dimensional echocardiography and standard ventriculography
Authors: Barrett M. J. , Jacobs L. , Gomberg J. , Horton L. , Wolf N. M. , Meister S. G.
Published: January 2015

Simultaneous contrast two‐dimensional echocardiograms and contrast ventriculograms were analyzed for 19 cardiac cycles in 6 patients. Ventriculographic volume was underestimated by 40 ± 4.5% (p <.001) by the contrast echocardiograms, despite good correlation (r = 0.88). Discrepancies could not be assigned to changes in volume between studies nor to a lack of precise endocardial definition. Simultaneous imaging demonstrated that the ultrasonic transducer was located 33° cephalad to the cardiac apex. Although angiographic volume was severely underestimated, ejection fraction (r = 0.93) and stroke volume (r = 0.90) could be calculated from two‐dimensional echocardiograms using regression equations.
Cardiovascular function in patients with progressive systemic sclerosis (scleroderma)
Authors: Gaffney F. A. , Anderson R. J. , Nixon J. V. , Blomqvist C. G. , Moore W. E.
Published: January 2015

Sixteen patients with progressive systemic sclerosis (PSS), including 3 with the “CREST” (calcinosis, Raynaud's, esophageal dysfunction, sclerodactyly, and/or telangiectasias) variant, were evaluated with resting M‐mode echocardiography and noninvasive measurements of cardiac output at rest and during submaximal exercise to determine the nature and extent of any cardiovascular impairment. No patient had arterial hypertension, significant renal impairment, clinical evidence of large vessel coronary artery disease, or severe pulmonary dysfunction. The duration of disease was 1 to 12 years (9 to 30 for patients with the CREST variant). Echocardiographic abnormalities included increased right ventricular dimension (3 patients), reduced left ventricular ejection fraction (3 patients), and pericardial effusion (3 patients). Cardiac index (CI) and stroke volume index (SVI) at rest were similar for patients and controls. Patients and controls were exercised to similar heart rates (130±3 vs 124±4; p, NS). Total peripheral resistance (TPR) was higher for patients (1123±81 vs 810±44 dyn·s·cm−5) and their mean SVI failed to increase significantly compared with sitting rest values (30±2 vs 35±3 ml/m2). The control subjects had the expected increase in SVI (36±2 vs 51 ±5; p < 0.01). Ten patients with an abnormal hemodynamic response to exercise had a normal echocardiographic circumferential fiber shortening (VCF) or ejection fraction (EF) at rest. The data indicate that PSS patients have a greater degree of cardiovascular dysfunction than would be predicted from clinical data and laboratory evaluation of cardiovascular and pulmonary function at rest. Multiple mechanisms, including right and left ventricular dysfunction and abnormal vasoconstrictor activity, are likely to contribute to the reduction in exercise capacity seen in patients with PSS.
Echocardiographic features of aortic ball valve prosthesis malfunction
Authors: Weisburst M. R. , Singh A. K. , Riley R. S.
Published: January 2015

A case of aortic ball valve prosthesis malfunction is described in which the poppet became alternately stuck in the open and closed position. The patient experienced chest pain followed by pulmonary edema and cardiac arrest. Malfunction of prosthetic valve was diagnosed on echocardiogram and cardiopulmonary resuscitation was carried out until a Bjork‐Shiley valve could be inserted in place of the faulty prosthesis. At the time of the operation, poppet migration had occurred and the poppet could not be found. Subsequent Bjork‐Shiley aortic valve prosthesis dysfunction was suggested by variation in the intensity of the aortic opening sound and in the duration of the systolic ejection period. Fluoroscopy revealed the missing poppet in the left ventricle. Following surgical removal of the poppet, “normal” Bjork‐Shiley valve function was restored.
Acute amphetamine cardiomyopathy in a drug addict
Authors: O'Neill M. E. , Arnolda L. F. , Coles D. M. , Nikolic G.
Published: January 2015

A case of acute left ventricular failure following an intravenous dose of amphetamine is described. The diagnosis was made by right heart catheterization. This is the first description of acute amphetamine cardiomyopathy in the medical literature.
The pathology of hypertension in a tropical environment
Authors: Isaacson C.
Published: January 2015

Hypertension is very common in blacks and occurs at a younger age than in whites. It behaves in an explosive manner with death occurring frequently from cerebral hemorrhage, uremia or congestive heart failure. Pathologically the majority have essential hypertension. The development of hypertension is related to urbanization and Westernization, as the incidence in rural blacks is low. Despite the high incidence of hypertension, myocardial infarction remains infrequent.
Cardiogoniometry
Authors: Sanz E. , Steger J. P. , Thie W.
Published: January 2015

Cardiogoniometry is a new method to test heart function. It consists of a simple computerized vectorcardiography with a system of leads derived for the construction of three orthogonal projections. With the aid of these three‐dimensional projections the cardiogoniometer, a microprocessor system, measures and computes the maximal vectors of depolarization (QRS) and repolarization (T). It also fixes the orientation of these two spatial vectors by projection on two planes (frontal and oblique sagittal) and determines the solid angle φ between them. Every third heart beat these five parameters and the preceding beat interval are printed out. In this way, a series of measurements is obtained in which only little disturbances of the signals of cardiac de‐ and repolarization occur. In patients with latent coronary insufficiency an abnormal position of the T vector can be detected long before the standard ECG shows a pathological pattern. Cardiogoniometry can be performed in the consulting room or at the bedside. It is noninvasive, painless, and free of risk. The value and limits of this new method are to be tested in comparison with the ECG and invasive methods in cardiology laboratories.
Serial M‐mode echocardiographic mapping in myocardial infarction: A quantitative evaluation of left ventricular wall motion abnormalities
Authors: Lindvall K. , Erhardt L. , Sjögren A.
Published: January 2015

M‐mode echocardiographic (echo) mapping was performed in 44 consecutive patients with a first acute transmural myocardial infarction (AMI). Regional left ventricular wall motion, as reflected by mean systolic wall velocity (V̄), was analyzed in 16 segments on day 1,2, 10, of hospitalization and after one year. Mean systolic wall velocity was significantly reduced (p < 0.05–0.01) in all segments indicated to be infarcted according to ECG. Anteroseptal and anterolateral AMIs showed similar V̄ impairment in anterior segments. In one latero‐apical segment in anterolateral AMI V̄ was significantly lower (p < 0.01), while anteroseptal AMI also showed lower values (p < 0.05) for the midsegment of the middle third of septum. Inferior and inferolateral AMI had similar reductions in V̄ in the inferior segments. In addition depressed wall motion (p < 0.05) was found in one posterior segment in inferior AMI and in two posteroseptal segments in inferolateral AMI. Following the AMI V̄ successively decreased in the 4 central segments in patients with anterior wall infarction during the first 3 days, followed by a significant (p < 0.001) improvement on day 10. No further significant changes were seen after one year. Centrally infarcted segments in inferior AMI showed a minor (p < 0.05) decrease in V̄ from day 1 to day 2, with similar V̄ on day 10. A minor improvement (p < 0.05) was found one year later. Segments adjacent to centrally infarcted segments showed V̄ values similar to infarcted segments during the first 24 hours, followed by rapid improvement in inferior AMI from day 2, with normalization by day 10. Border segments in anterior AMI showed depressed V̄ values during the first 3 days, followed by a normalization by day 10. Noninfarcted segments in patients with inferior AMI showed hyperkinetic wall motion during the first 10 days, with normalization at the one year follow‐up. The changes were moderate though peak V̄ values on days 2 or 3 were significantly higher (p < 0.05) than values one year later. Similarly, wall motion in noninfarcted segments in patients with anterior AMI reached hyperkinetic levels days 3 and 10, which was significantly higher (p < 0.01) than values on days 1, 2, or after one year.
Correlation between calcific aortic stenosis diagnosed by two‐dimensional echocardiography and cardiac catheterization
Authors: Nair C. K. , Aronow W. S. , Sketch M. H. , Mohiuddin S. M. , Stokke K. , Ryschon K.
Published: January 2015

This retrospective study correlates the severity of calcific aortic stenosis determined by two‐dimensional (2‐D) echocardiography with the aortic valve area determined by catheterization in 57 patients. Aortic valve leaflet calcification was diagnosed by cineangiography in 50 (88%) of 57 patients and by 2‐D echo in 57 (100%) of 57 patients (p < 0.025). An agreement between severity of aortic stenosis by catheterization and 2‐D echo occurred in 22 (39%) of 57 patients. Chi‐square and logistic regression analyses showed no correlation between the severity of aortic stenosis and the 2‐D echo variables: left ventricular wall thickness, left ventricular diastolic dimension, left ventricular systolic dimension, aortic root diameter, and left atrial dimension. We conclude that 2‐D echo detects aortic leaflet calcification better than cineangiography. However, the severity of aortic stenosis determined by 2‐D echo correlates poorly with the severity of aortic stenosis determined by cardiac catheterization.
Pulmonary varices, benign congenital anomalies simulating perihilar masses of various etiologies
Authors: Platzker J. , Goldhammer E. , Simon J. , Abinader E.
Published: January 2015

Pulmonary varices are rare and relatively benign congenital malformations. These localized aneurysmatic dilatations of pulmonary veins drain normally to the left atrium. Their radiological appearance may simulate perihilar masses of neoplastic or granulomatous origin and pulmonary arteriovenous fustulae, thus, potentially leading to diagnostic pitfalls. The diagnosis is made during the venous phase of pulmonary angiography which is always necessary in order to avoid unnecessary surgical procedures. An illustrative case and discussion of the subject is presented herein.
Recurrent coronary artery fistula
Authors: Kostis J. B. , Burns J. J. , Moreyra A. E. , Pichard A. D.
Published: January 2015

A patient with a large fistula from the left circumflex coronary artery to the coronary sinus that recurred in spite of proximal and distal ligation is presented. It suggests that ligation is not an adequate procedure for large coronary fistulae. Division and oversewing should be done whenever feasible.
Does alcohol intensify the hemodynamic effects of nitroglycerin?
Authors: Kupari M. , Heikkilä J. , Ylikahri R.
Published: January 2015

To evaluate the combined effects of alcohol and nitroglycerin on cardiovascular hemodynamics, M‐mode echocardiography and sphygmomanometric blood pressure measurements were performed on two groups of normal subjects, before and after the administration of nitroglycerin, both in the sober state and during alcohol intoxication. In the first part of the study, 0.5 mg of nitroglycerin was given sublingually to 10 healthy volunteers 5–10 minutes after they had ingested 1 g/kg body weight of ethanol within a 30‐minute period. Control experiments substituted juice for ethanol. The combined effects of ethanol and nitroglycerin on left ventricular diameters, systolic blood pressure, and wall stress were not significantly different from those of juice and nitroglycerin; heart rate and diastolic blood pressure were increased more (p < 0.01) by ethanol and nitroglycerin. In the second part of the study, 1.0 mg of nitroglycerin was administered to a second group of 10 healthy volunteers, first in the control state and again 60 minutes after the subjects had ingested 1 g/kg body weight of ethanol within a 60‐minute period. Systolic blood pressure and wall stress were significantly lower (p < 0.01) after ethanol and nitroglycerin than after nitroglycerin before ethanol intake. We conclude that the nitroglycerin‐induced reductions in left ventricular preload and afterload are not increased by alcohol during the very early phase of intoxication. However, 1 hour or more after alcohol ingestion nitroglycerin may decrease left ventricular afterload to a level significantly lower than that seen after nitroglycerin in the sober state. These data suggest first, that alcohol does not deprive nitroglycerin of its beneficial hemodynamic effects, and second, that the susceptibility to nitroglycerin‐induced hypotension may be increased during the late phase of intoxication.
Linearly constrained minimum variance spatial filtering for localization of conductivity changes in electrical impedance tomography
Authors: Fernández‐Corazza M. , von Ellenrieder N. , Muravchik C. H.
Published: January 2015

We localize dynamic electrical conductivity changes and reconstruct their time evolution introducing the spatial filtering technique to electrical impedance tomography (EIT). More precisely, we use the unit‐noise‐gain constrained variation of the distortionless‐response linearly constrained minimum variance spatial filter. We address the effects of interference and the use of zero gain constraints. The approach is successfully tested in simulated and real tank phantoms. We compute the position error and resolution to compare the localization performance of the proposed method with the one‐step Gauss–Newton reconstruction with Laplacian prior. We also study the effects of sensor position errors. Our results show that EIT spatial filtering is useful for localizing conductivity changes of relatively small size and for estimating their time‐courses. Some potential dynamic EIT applications such as acute ischemic stroke detection and neuronal activity localization may benefit from the higher resolution of spatial filters as compared to conventional tomographic reconstruction algorithms. Copyright © 2015 John Wiley & Sons, Ltd.
Targeted Treatment of Cancer with Nanotherapeutics Based on Mesoporous Silica Nanoparticles
Authors: Knežević Nikola Ž. , Durand Jean‐Olivier
Published: January 2015

The properties of mesoporous silica nanoparticles (MSN) (biocompatibility, surface area, particle diameter, mesoporous structure, and ease of functionalization) are reviewed regarding their benefits for the construction of cancer‐targeting drug delivery systems, with an overview of literature reports within this research area. Intrinsic properties characteristic of tumor tissues (enhanced permeability and retention effect, overexpressed receptors, and acidic extracellular pH) are further discussed which can be utilized for cancer targeting. Recent literature reports are also accounted concerning MSN‐based cancer targeting that takes advantage of characteristics of the tumor environment and also nanotherapeutics capable of stimulus (acidification, exposure to light irradiation, magnetic field) responsive drug delivery. Finally, gene therapy approaches for cancer treatment and MSN‐based gene delivery vectors are reviewed. The research on mesoporous silicates possesses great potential for the development of complex multipurpose nanotherapeutics for simultaneous application in effective targeted treatment and imaging of cancer tissues.
Carbon Dioxide Splitting in a Dielectric Barrier Discharge Plasma: A Combined Experimental and Computational Study
Authors: Aerts Robby , Somers Wesley , Bogaerts Annemie
Published: January 2015

Plasma technology is gaining increasing interest for the splitting of CO2 into CO and O2. We have performed experiments to study this process in a dielectric barrier discharge (DBD) plasma with a wide range of parameters. The frequency and dielectric material did not affect the CO2 conversion and energy efficiency, but the discharge gap can have a considerable effect. The specific energy input has the most important effect on the CO2 conversion and energy efficiency. We have also presented a plasma chemistry model for CO2 splitting, which shows reasonable agreement with the experimental conversion and energy efficiency. This model is used to elucidate the critical reactions that are mostly responsible for the CO2 conversion. Finally, we have compared our results with other CO2 splitting techniques and we identified the limitations as well as the benefits and future possibilities in terms of modifications of DBD plasmas for greenhouse gas conversion in general.
Mobility management schemes for real‐time traffic and resource allocation in IEEE 802.16e mobile network
Authors: El‐Hammani Sihame , Ibrahimi Khalil , Bouyakhf El‐Houssine , El‐Azouzi Rachid
Published: January 2015

In this paper, our aim is to develop in IEEE802.16e Wireless Networks with link adaptation, in the presence of real‐time traffic call admission control (CAC) schemes. These CAC propose various scenarios of resource splitting and handling the intracell mobility. In particular, we consider two types of intracell mobility classes : low mobility class for mobiles moving usually with low speed between the neighboring regions of the cell and high mobility class for those moving with high speed and that can skip more than one region before changing their modulation. For this reason, we assume a time threshold Tth that determines the minimum time a call must remain in a region before the base station changes its modulation. And we compare it with the time that a call may spend in a region to decide whether the base station will change its modulation or not.

In the beginning, we introduce two CAC schemes. In the first one, we reserve a portion of resources to mobiles in migration with both high and low mobility. And in the second one, we give the priority just to mobiles in migration with high mobility. Then, we calculate the impact in the blocking and dropping probabilities. We show by numerical results that by the proposed CAC schemes, we can find a resource management that outperforms well under different types of mobility. But, to find a good tradeoff between dropping the calls in migration and blocking the new calls, we introduce the optimization problem in the second part. So, we are faced to the necessity of optimizing the results found in the first part. Therefore, we define an objective function to optimize, in order to ensure the highest quality of service for users and to give a better stability state between the dropping and blocking probability. We show that the proposed objective function gives the optimal resources allocation between the migrating and new arriving calls in the cell. Copyright © 2015 John Wiley & Sons, Ltd.
A review of scalability and topological stability issues in IEEE 802.11s wireless mesh networks deployments
Authors: Sampaio S. , Souto P. , Vasques F.
Published: January 2015

Scalability and topological stability are two of the most challenging issues in current wireless mesh networks (WMNs) deployments. In the literature, both the scalability and the topological stability of WMNs are described as likely to suffer from poor performance due to the ad hoc nature of the underlying IEEE 802.11 mechanisms. The main contribution of this article is a comprehensive review of the main topological stability and scalability‐related issues in IEEE 802.11s‐based networks. Moreover, the most relevant proposed solutions are surveyed, where both the drawbacks and the merits of each proposal are highlighted. At the end of the article, some open research challenges are presented and discussed. It is expected that this work may serve as motivation for more and deeper research on these issues to allow the design of future more stable and scalable IEEE 802.11s mesh networks deployments. Copyright © 2015 John Wiley & Sons, Ltd.
In vitro metabolism of the lignan (−)‐grandisin, an anticancer drug candidate, by human liver microsomes
Authors: Barth Thiago , Habenschus Maísa Daniela , Lima Moreira Fernanda , Ferreira Leandro De Santis , Lopes Norberto Peporine , Moraes de Oliveira Anderson Rodrigo
Published: January 2015

(−)‐grandisin is a tetrahydrofuran lignan that displays important biological properties, such as trypanocidal, anti‐inflammatory, cytotoxic, and antitumor activities, suggesting its utility as a potential drug candidate. One important step in drug development is metabolic characterization and metabolite identification. To perform a biotransformation study of (−)‐grandisin and to determine its kinetic properties in humans, a high performance liquid chromatography (HPLC) method was developed and validated. After HPLC method validation, the kinetic properties of (−)‐grandisin were determined. (−)‐grandisin metabolism obeyed Michaelis‐Menten kinetics. The maximal reaction rate (Vmax) was 3.96 ± 0.18 µmol/mg protein/h, and the Michaelis‐Menten constant (Km) was 8.23 ± 0.99 μM. In addition, the structures of the metabolites derived from (−)‐grandisin were characterized via gas chromatography‐mass spectrometry (GC‐MS) and liquid chromatography‐mass spectrometry (LC‐MS) analysis. Four metabolites, 4‐O‐demethylgrandisin, 3‐O‐demethylgrandisin, 4,4′‐di‐O‐demethylgrandisin, and a metabolite that may correspond to either 3,4‐di‐O‐demethylgrandisin or 3,5‐di‐O‐demethylgrandisin, were detected. CYP2C9 isoform was the main responsible for the formation of the metabolites. These metabolites have not been previously described, demonstrating the necessity of assessing (−)‐grandisin metabolism using human‐derived materials. Copyright © 2015 John Wiley & Sons, Ltd.
Practical Application of ±250‐kV DC‐XLPE Cable for Hokkaido–Honshu HVDC Link
Authors: Watanabe Chizuo , Itou Yasuo , Sasaki Hidetaka , Murata Yoshinao , Suizu Makoto , Sakamaki Masatoshi , Watanabe Masaru , Katakai Shoshi
Published: January 2015

The long‐term dc properties of DC‐XLPE insulation materials, which have been developed for dc use, were investigated. It was found that the lifetime of DC‐XLPE under dc voltage application is extended by the addition of nano‐sized filler. The time dependence of the space charge distribution at 50 kV/mm was observed for 7 days. Almost no accumulation of space charge in DC‐XLPE was found. The 250‐kV DC‐XLPE cables and accessories were manufactured and subjected to a type test and PQ test for use in the Hokkaido–Honshu dc link facility owned by the Electric Power Development Co., Ltd. These tests were performed under conditions that included a polarity reversal test for line commutated converter (LCC) systems as recommended in CIGRE TB 219. The test temperature was 90 °C. The type test and PQ test were successfully completed. The DC‐XLPE cable and accessories were installed in summer 2012 for the Hokkaido–Honshu dc link. After the installation of the dc extruded cable system, a dc high‐voltage test at 362.5 kV (=1.45 PU) for 15 min was successfully completed in accordance with CIGRE TB 219. This dc extruded cable system was put into operation in December 2012 as the world's highest‐voltage extruded dc cable in service and the world's first dc extruded cable for a LCC system including polarity reversal operation.
UPTe, ThPTe and U2PTe2O: Actinide Pnictide Chalcogenides with Diphosphide Anions
Authors: Stolze Karoline , Isaeva Anna , Schwarz Ulrich , Doert Thomas
Published: January 2015

Crystal structure determination of UPTe revealed a UGeTe derivative structure with a pseudo‐tetragonal unit cell with lattice parameters a = 410.1(1) pm and c = 1697.1(1) pm at 120(2) K. ThPTe can be regarded as isotypic according to powder X‐ray diffraction data, its pseudo‐tetragonal lattice parameters are a = 425.05(1) pm and c = 1726.8(1) pm at 296(1) K. Real‐space topological analysis of the chemical bonding and Raman data reveal the presence of P2 units. U2PTe2O can be considered as a partially oxidised phosphide telluride with a pseudo‐tetragonal unit cell, a = 403.7(1) pm, and c = 3206.8(10) pm at 120(2) K. Single‐crystal X‐ray diffraction data of UPTe and U2PTe2O indicate an ordered orientation of the P2 dumbbells leading to a monoclinic distortion, which implies a symmetry decrease to space group I11m.
Perfluoroalkylation of Nitrones for the Synthesis of a Series of Fucosidase Inhibitors
Authors: Paszkowska Jadwiga , Fernandez Olalla Novo , Wandzik Ilona , Boudesoque Stéphanie , Dupont Laurent , Plantier‐Royon Richard , Behr Jean‐Bernard
Published: January 2015

Fucosidase inhibitors represent captivating targets for various biological applications. Iminosugars featuring a fluoroalkyl chain in the pseudoanomeric position were synthesized by nucleophilic addition of a perfluoroalkyl Grignard reagent to a nitrone. Reduction of the N–O bond of the hydroxylamine was achieved by treatment with an aqueous solution of sulfur dioxide. The pKa = 4.5 of the target pyrrolidine reflected a strong electronic effect of the fluoroalkyl chain. Inhibitory potencies of the fluorinated iminosugars and their corresponding hydroxylamines were evaluated against α‐L‐fucosidase at various pH values.
An Overview of the Latest Graphene‐Based Sensors for Glucose Detection: the Effects of Graphene Defects
Authors: Carbone Marilena , Gorton Lo , Antiochia Riccarda
Published: January 2015

In this review, we analyze several types of graphene‐based sensors for glucose detection with respect to their preparation, properties and efficiency in electrochemical processes. Graphene may display different types of defects, which play a role in the electron transfer processes. Oxygenated groups on the edges of graphene planes reduce the graphene in‐plane conductivity, but may enhance the heterogeneous electron/proton transfer constant. Other positive effects of defects are related to the shortening of the distance between active centers and electrodes upon enzyme or protein immobilization. However, though by different mechanisms, all types of graphene enhance the electrochemical response at the electrode.
Extended Kalman filter for material parameter estimation in nonlinear structural finite element models using direct differentiation method
Authors: Ebrahimian Hamed , Astroza Rodrigo , Conte Joel P.
Published: January 2015

This paper presents a novel nonlinear finite element (FE) model updating framework, in which advanced nonlinear structural FE modeling and analysis techniques are used jointly with the extended Kalman filter (EKF) to estimate time‐invariant parameters associated to the nonlinear material constitutive models used in the FE model of the structural system of interest. The EKF as a parameter estimation tool requires the computation of structural FE response sensitivities (total partial derivatives) with respect to the material parameters to be estimated. Employing the direct differentiation method, which is a well‐established procedure for FE response sensitivity analysis, facilitates the application of the EKF in the parameter estimation problem. To verify the proposed nonlinear FE model updating framework, two proof‐of‐concept examples are presented. For each example, the FE‐simulated response of a realistic prototype structure to a set of earthquake ground motions of varying intensity is polluted with artificial measurement noise and used as structural response measurement to estimate the assumed unknown material parameters using the proposed nonlinear FE model updating framework. The first example consists of a cantilever steel bridge column with three unknown material parameters, while a three‐story three‐bay moment resisting steel frame with six unknown material parameters is used as second example. Both examples demonstrate the excellent performance of the proposed parameter estimation framework even in the presence of high measurement noise. Copyright © 2015 John Wiley & Sons, Ltd.
Delayed hepatocellular carcinoma model for end‐stage liver disease exception score improves disparity in access to liver transplant in the United States
Authors: Heimbach Julie K. , Hirose Ryutaro , Stock Peter G. , Schladt David P. , Xiong Hui , Liu Jiannong , Olthoff Kim M. , Harper Ann , Snyder Jon J. , Israni Ajay K. , Kasiske Bertram L. , Kim W. Ray
Published: January 2015

The current system granting liver transplant candidates with hepatocellular carcinoma (HCC) additional Model for End‐Stage Liver Disease (MELD) points is controversial due to geographic disparity and uncertainty regarding optimal prioritization of candidates. The current national policy assigns a MELD exception score of 22 immediately upon listing of eligible patients with HCC. The aim of this study was to evaluate the potential effects of delays in granting these exception points on transplant rates for HCC and non‐HCC patients. We used Scientific Registry of Transplant Recipients data and liver simulated allocation modeling software and modeled (1) a 3‐month delay before granting a MELD exception score of 25, (2) a 6‐month delay before granting a score of 28, and (3) a 9‐month delay before granting a score of 29. Of all candidates waitlisted between January 1 and December 31, 2010 (n = 28,053), 2773 (9.9%) had an HCC MELD exception. For HCC candidates, transplant rates would be 108.7, 65.0, 44.2, and 33.6 per 100 person‐years for the current policy and for 3‐, 6‐, and 9‐month delays, respectively. Corresponding rates would be 30.1, 32.5, 33.9, and 34.8 for non‐HCC candidates. Conclusion: A delay of 6‐9 months would eliminate the geographic variability in the discrepancy between HCC and non‐HCC transplant rates under current policy and may allow for more equal access to transplant for all candidates. (Hepatology 2015;61:1643–1650)
Randomized trial of interferon‐ and ribavirin‐free ombitasvir/paritaprevir/ritonavir in treatment‐experienced hepatitis C virus–infected patients
Authors: Chayama Kazuaki , Notsumata Kazuo , Kurosaki Masayuki , Sato Ken , Rodrigues Lino , Setze Carolyn , Badri Prajakta , Pilot‐Matias Tami , Vilchez Regis A. , Kumada Hiromitsu
Published: January 2015

Approximately 2 million Japanese individuals are infected with hepatitis C virus and are at risk for cirrhosis, end‐stage liver disease, and hepatocellular carcinoma. Patients in whom interferon (IFN)/ribavirin (RBV) therapy has failed remain at risk as effective therapeutic options are limited. This phase 2, randomized, open‐label study evaluated an IFN‐ and RBV‐free regimen of once‐daily ombitasvir (ABT‐267), an NS5A inhibitor, plus paritaprevir (ABT‐450), an NS3/4A protease inhibitor dosed with ritonavir (paritaprevir/ritonavir), in pegylated IFN/RBV treatment–experienced Japanese patients with hepatitis C virus subtype 1b or genotype 2 infection. Patients without cirrhosis (aged 18‐75 years) with subtype 1b infection received ombitasvir 25 mg plus paritaprevir/ritonavir 100/100 mg or 150/100 mg for 12 or 24 weeks; patients with genotype 2 infection received ombitasvir 25 mg plus paritaprevir/ritonavir 100/100 mg or 150/100 mg for 12 weeks. Sustained virologic response (SVR) at posttreatment week 24 (SVR24) was the primary endpoint. Adverse events were collected throughout the study. One hundred ten patients received ≥1 dose of study medication. In the subtype 1b cohort, SVR24 rates were high (88.9%‐100%) regardless of paritaprevir dose or treatment duration. In the genotype 2 cohort, SVR24 rates were 57.9% and 72.2% with 100 mg and 150 mg of paritaprevir, respectively. The SVR24 rate was higher in patients with subtype 2a (90%) than 2b (27%). Concordance between SVR12 and SVR24 was 100%. The most common adverse events overall were nasopharyngitis (29%) and headache (14%). Conclusion: In this difficult‐to‐treat population of patients in whom prior pegylated IFN/RBV had failed, ombitasvir/paritaprevir/ritonavir demonstrated potent antiviral activity with a favorable safety profile among Japanese patients with hepatitis C virus genotype 1b or 2a infection. (Hepatology 2015;61:1523–1532)
Hepatocyte buds derived from progenitor cells repopulate regions of parenchymal extinction in human cirrhosis
Authors: Stueck Ashley E. , Wanless Ian R.
Published: January 2015

Repair of cirrhotic livers occurs, in part, by repopulation with hepatocytes through the stem/progenitor pathway. There remain many uncertainties regarding this pathway. Hepatocyte “buds” occurring in broad septa are hypothesized to be the anatomic manifestation of this pathway. Our purpose was to define a morphologic sequence of bud maturation to allow a quantitative measure of the importance of the stem/progenitor pathway in humans. Histologic sections from 37 liver resection specimens were stained with trichrome, epithelial cell adhesion molecule (EpCAM), K19, CD34, glutamine synthetase (GS), and Ki‐67. Specimens were stratified by etiology (10 biliary, 22 nonbiliary, five controls) and stage. Buds were defined as clusters of hepatocytes within septa. Five levels of bud maturation (0‐4) were defined by the progressive increase in hepatocyte progeny relative to cholangiocytes. Level 0 single‐cell buds are K19+/GS+/EpCAM+/Heppar1−. In level 1, the progeny are morphologically hepatocytes (K19−/GS+/EpCAM+/Heppar1+). In level 2‐4 buds, hepatocytes increase and become progressively GS− and EpCAM−. Associated endothelium is CD34+ in level 1‐2 buds and becomes CD34− near hepatic veins in level 3‐4 buds. Progeny of the bud sequence may represent up to 70% of hepatocytes (immaturity index of 70%). In biliary disease, bud number is reduced in association with duct loss and cholestatic destruction of nascent buds. Conclusions: The stem/progenitor pathway, manifested anatomically by the bud sequence, is a major mechanism for repopulation of cirrhotic livers. The bud sequence reveals some critical features of hepatic morphogenesis, including that 1) the majority of distal cholangiocytes have stem‐like properties, and 2) availability of bile ducts and/or venous drainage are limiting factors for regeneration. (Hepatology 2015;61:1696–1707)
Ambidexterity in SBUs: TMT Behavioral Integration and Environmental Dynamism
Authors: Yitzhack Halevi Meyrav , Carmeli Abraham , Brueller Nir N.
Published: January 2015

This study seeks to advance previous research by linking top management team (TMT) processes to organizational ambidexterity, and highlights the importance of environmental dynamism as a boundary condition on the effectiveness of TMTs in promoting balance between exploratory and exploitative learning. The findings from multiple respondents (245 TMT members, including the CEO of the SBUs, and 883 employees) in 101 small‐sized strategic business units (SBUs) with a defined product line indicate that TMT behavioral integration helps build ambidexterity, but that the influence of TMT behavioral integration on ambidexterity is stronger when the task environment is characterized by a high level of dynamism. These findings contribute to a better understanding of the conditions under which behaviorally integrated TMTs are able to pursue an ambidextrous orientation in relatively small‐sized units. © 2015 Wiley Periodicals, Inc.
Surface modified Fe/silica floating magnetic materials for efficient oil removal
Authors: Carvalho Lílian Amaral , Martins Bárbara Carolina Lourenço Papa , Lago Rochel Montero , Araujo Maria Helena
Published: January 2015

BACKGROUND

Remediation of oil spillage accidents requires efficient and low cost floating absorbents to remove small amounts of contaminant oil. In this work, a highly hydrophobic floating magnetic macroporous structure based on silica encapsulated Fe nanoparticles was prepared and used for oil absorption from water.

RESULTS

The magnetic macroporous materials were prepared by silica encapsulation of iron oxide/hydroxide nanoparticles followed by a thermal treatment with H2. Mössbauer, XRD, SEM/TEM, CHN, IR, TG/DTA and contact angle analyses showed that the Fe oxides nanoparticles are reduced by H2 to form Feo cores protected by silica which sinters to form a macroporous network. The surface reaction with octadecyltrimethoxysilane (Si(CH3O)3C18H37) was used to produce highly hydrophobic materials.

CONCLUSIONS

The materials obtained showed very high oil absorption capacities for different model contaminants, i.e. petroleum, soy bean oil, diesel, gasoline and xylene removal. The results are discussed in terms of a macroporous structure with strong capillarity combined with a very hydrophobic surface. © 2015 Society of Chemical Industry
Synthesis of Some New Thiazole, Oxazole, Pyrimidine and Pyridazine Derivatives from 2‐cyano‐N‐octadecyl‐acetamide as Antimicrobial and Surface Active Agents
Authors: El‐Sayed Refat , Ahmed Saleh A
Published: January 2015

The motivation behind the present work is to synthesize some nonionic surfactants containing heterocyclic nucleus with intermediate fatty compounds for improving their surfactants properties. 2‐Cyano‐N‐octadecylacetamide was utilized as key intermediate for the synthesis of some new thiazole, pyrazole, oxazole, pyrimidine, 1,3‐dithiolane, thiophene, coumarin, oxazine and pyridazine derivatives. The newly synthesized compounds undergo propoxylation using propylene oxide to afford nonionic surface active agents. The antimicrobial and surface activities were evaluated and characterized through investigations of their spreading behavior in monolayer on water.
Redefining Informality and Measuring its Determinants: Evidence from the Russian Labour Market
Authors: Lehmann Hartmut , Zaiceva Anzelika
Published: January 2015

Although informality impacts countries' economic development, the recent recession may have increased the incidence of informal activities. We take advantage of a rich data set on Russia before and after the economic downturn and demonstrate that the incidence of informal employment varies across the definitions. However, the determinants of informal employment are roughly stable across different measures, apart from firm size. Employing a direct measure of risk attitudes, we also show that risk‐averse individuals are less likely to select themselves into informality. Regressions suggest a lower likelihood to be a formal employee post‐2008, especially for individuals with little education and immigrants. Copyright © 2015 John Wiley & Sons, Ltd.
Growth, survival, and heavy metal (Cd and Ni) uptake of spinach (Spinacia oleracea) and fenugreek (Trigonella corniculata) in a biochar‐amended sewage‐irrigated contaminated soil
Authors: Younis Uzma , Qayyum Muhammad Farooq , Shah M. Hasnain Raza , Danish Subhan , Shahzad Ahmad Naeem , Malik Saeed Ahmad , Mahmood Seema
Published: January 2015

Irrigation of arable land with contaminated sewage waters leads to the accumulation of trace metals in soils with subsequent phyto‐/zootoxic consequences. In this study, biochar derived from cotton sticks was used to amend an agricultural silt‐loam soil that had been previously irrigated with trace metal contaminated sewage waters. Metal accumulation and toxicity to spinach (Spinacia oleracea) and fenugreek (Trigonella corniculata) was investigated by measuring concentrations of Cd and Ni in plant tissues and various photosynthetic and biochemical activities of plants. Positive impacts of biochar on both spinach and fenugreek were observed in terms of biomass production that increased from 29% to 36% in case of spinach, while for fenugreek this increase was 32% to 36%. In the control treatment there was an increase in malondialdihyde, soluble sugar, and ascorbic acid contents, indicating heavy metal stress. Biochar applications increased soluble proteins and amino acids in plants and reduced the uptake of Cd from 5.42 mg kg−1 at control to 3.45 mg kg−1 at 5% biochar amended soil and Ni (13.8 mg kg−1 to 7.3 mg kg−1 at 5% biochar) by the spinach plants. In fenugreek, the Cd was reduced from 7.72 mg kg−1 to 3.88 mg kg−1 and reduction in Ni was from 15.45 mg kg−1 to 9.46 mg kg−1 at 5% biochar treated soil, reducing the possibility of transfer up the food chain. This study demonstrates that the use of biochar made from cotton‐sticks, as an amendment to arable soils that have received contaminated irrigation water, could improve plant growth and decrease Cd and Ni uptake to crops, alleviating some of the negative impacts of using sewage waters on arable land.
Influence of dietary fibre on gluten proteins structure – a study on model flour with application of FT‐Raman spectroscopy
Authors: Nawrocka A. , Szymańska‐Chargot M. , Miś A. , Ptaszyńska A. A. , Kowalski R. , Waśko P. , Gruszecki W. I.
Published: January 2015

Dietary fibres are regarded as the source of polysaccharides and antioxidants such as polyphenols. However, addition of dietary fibre to bread causes significant reduction in its quality. The bread quality is connected with the structure of gluten proteins. For this reason, Fourier transform Raman spectroscopy was applied to determine changes in structure of gluten proteins modified by seven dietary fibres. The fibres were added to model flour reconstituted with wheat gluten and wheat starch. The model flour was used to provide gluten proteins of definite structure. The obtained results showed that six out of seven fibres caused similar changes in β‐turn structures. The appearance of the band at 1642 cm−1 and the shift toward lower wavenumbers of the band at 1670 cm−1 in the difference spectra indicated hydrogen bonding of carbonyl groups in β‐turns leading to protein folding/aggregation. Addition of fibre preparations caused also changes in conformation of disulfide bridges (S–S), corresponding to transformation to trans‐gauche‐gauche and trans‐gauche‐trans conformations at the expense of the stable gauche‐gauche‐gauche conformation. The S–S bonds in less stable conformations were formed inside the protein complex as well as between protein complexes in the form of β‐structures. Generally, the observed changes in gluten proteins after addition of dietary fibres were results of interactions between fibre polysaccharides and gluten proteins rather than between polyphenols and gluten proteins. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of amaranth addition on the pro‐vitamin A content, and physical and antioxidant properties of extruded pro‐vitamin A‐biofortified maize snacks
Authors: Beswa Daniso , Dlamini Nomusa R , Amonsou Eric O , Siwela Muthulisi , Derera John
Published: January 2015

BACKGROUND

Pro‐vitamin A‐biofortified maize snacks with added leafy vegetable may have a potential as nutritious and health‐promoting products, especially in addressing vitamin A deficiency, which is prevalent in developing regions. The objective of the study was to determine the effects of adding amaranth leaf powder on the physical, antioxidant properties and pro‐vitamin A content of extruded pro‐vitamin A‐biofortified maize snacks. Extruded snacks were processed using four pro‐vitamin A‐biofortified maize varieties that were composited with amaranth leaf powder at 0%, 1% and 3% (w/w) substitution levels.

RESULTS

At higher amaranth concentration, the expansion ratio of the snacks decreased, while their hardness increased by as much as 93%. The physical quality of the snacks may therefore need improvement. As amaranth was increased, the phenolic content and antioxidant activity of the snacks increased as well as the pro‐vitamin A content.

CONCLUSION

Pro‐vitamin A‐biofortified maize with added amaranth has a potential for use in nutritious and healthy extruded snacks. There are limited studies reporting on processing pro‐vitamin A maize with complementary plant foods, which is common with white maize in southern Africa; thus the current study serves as a baseline. Copyright © 2015 Society of Chemical Industry
Synthesis, Characterization, and Catalytic Activity of New Cu(II) Complexes of Schiff Base: Effective Catalysts for Decolorization of Acid Red 37 Dye Solution
Authors: Elsherbiny Abeer S. , El‐Ghamry Hoda A.
Published: January 2015

In this paper, three new Cu(II) Schiff base complexes with three different anions (acetate, chloride, and nitrate) were successfully synthesized and characterized by elemental analysis, mass spectra, molar conductance, FT‐IR, NMR,UV–vis spectroscopy, magnetic moment, ESR, and thermal analysis. The catalytic performances of these complexes in decolorization of azo dye, Acid Red 37, were evaluated. Copper(II) complexes were found to be an efficient catalyst for decolorization of Acid Red 37 in the presence of hydrogen peroxide. The catalytic investigation revealed that the Cu(II) complex with acetate anion (complex 1) performed the highest catalytic activity. The kinetics of the decolorization of AR37 with this catalyst was studied, and the observed rate constant was determined. The effects of different reaction parameters such as catalyst dosage, solution pH, initial concentration of H2O2, dye solution, and reaction temperature on the reaction rate constant were studied. The best reacting conditions should be catalyst dosage = 0.004 g, initial pH 4.0, [H2O2]0 = 0.8 M, and [AR37]0 = 1.16 M at temperature 25°C. Under these conditions, about 99% of AR37 was decolorized within 60 min. The results indicated that the Cu(II) complex with the acetate anion is a promising catalyst for wastewater treatment.
Water‐Soluble Thermoresponsive α‐Helical Polypeptide with an Upper Critical Solution Temperature: Synthesis, Characterization, and Thermoresponsive Phase Transition Behaviors
Authors: Deng Yong , Xu Yanzhi , Wang Xi , Yuan Qiulin , Ling Ying , Tang Haoyu
Published: January 2015

Water‐soluble polypeptides bearing 1‐alkylimidazolium (methyl or n‐butyl) and various counter‐anions (i.e., Cl−, I− or BF4−) are prepared by ring‐opening polymerization of γ‐4‐chloromethylbenzyl‐l‐glutamate‐based N‐carboxyanhydride (3), post‐polymerization of poly(γ‐4‐chloromethylbenzyl‐l‐glutamate) (4), and ion‐exchange reaction. Circular dichroism (CD) analysis reveals that the resulting polypeptides adopt an α‐helical conformation in water with a fractional helicity in the range of 30%–56% at 20 °C and exhibit good conformational stability against temperature variations. The polypeptides exhibit lower critical solution temperature (LCST)‐type or upper critical solution temperature (UCST)‐type transitions in organic solvents or in water. The UCST‐type transition temperature (Tpt) in water is independent on the molecular weight, yet it decreases upon addition of NaCl and increases upon addition of NaI or NaBF4, suggesting a mainly electrostatic interaction mechanism.

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