bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolated tricuspid stenosis: Report of a case submitted to valvar commissurotomy
Authors: Schlesinger P. , Benchimol C. B. , Lopes A. S. , Barbosa J. , Jasbik W. , Benchimol A. B.
Published: January 2015

In this report, a rare case of tricuspid stenosis uncomplicated by other valve lesions is presented, with clinical, hemodynamic, echocardiographic, and angiographic studies. The patient was markedly incapacitated, mostly as a result of a restricted cardiac output. Tricuspid commissurotomy was performed, with a stenotic deformity of a bicuspid atrioventricular valve, probably of congenital origin, found at surgery. Considerable improvement was observed, notwithstanding the persistence of some signs of residual tricuspid obstruction as a result of an incomplete commissurotomy, to avoid increasing the slight degree of preexistent valvar regurgitation.
Heparin effect on plasma fibrinogen in the thrombophilic syndrome
Authors: Ruggiero H. A. , Castellanos H. , Caprissi L. F. , De Caprissi E. S. , Ruggiero L. H. R.
Published: January 2015

The effects of heparin were studied in a group of 42 patients with preinfarction angina (PA) and acute myocardial infarction (AMI) whose plasma fibrinogen was increased. Plasma fibrinogen was measured by the turbidimetric method in timol turbidimetric units. Statistically significant results proved that heparin reduces the plasma fibrinogen progressively over a treatment period of 6 weeks. During the first three weeks a dose of 1 cc (50 mg or 5000 IU) was given by intravenous injection at 6‐h intervals, this was followed by a dose of 2 cc (100 mg or 10,000 IU) given by subcutaneous injection at 12‐h intervals for a further three weeks. Hyperfibrinogenemia is perhaps one of the most important factors in the thrombophilic syndrome, and at the same time it is one of the fundamental physiopathological alterations observed in AMI and PA. Because heparin reduces hyperfibrinogenemia it has a beneficial effect in these diseases.
Penetration of netilmicin into heart valves, subcutaneous and muscular tissue of patients undergoing heart surgery
Authors: Just H.‐M. , Eschenbruch E. , Schmuziger M. , Daschner F. D.
Published: January 2015

In 57 patients undergoing heart surgery concentrations of netilmicin in plasma, heart valves, muscle, and subcutaneous tissue were determined after a 5 min intravenous bolus injection of 1.5 mg/kg body weight. Within 8 h netilmicin serum concentration declined from 3 μg/ml to 1 μg/ml. In heart valves the concentrations during heart surgery were high enough to inhibit most staphylococci, Klebisiella, Enterobacter and Escherichia coli strains. No different serum and tissue concentrations in patients with and without extracorporal circulation could be found.
Iatrogenic postoperative left ventricular outflow tract obstruction
Authors: Nakhjavan F. K. , Yazdanfar S. , Bhasin V. , Goldberg H.
Published: January 2015

A 56‐year‐old female, who underwent aortocoronary bypass graft for occlusion of anterior descending artery is reported, who postoperatively developed a harsh systolic murmur, mitral regurgitation, and intraventricular systolic pressure gradient suggestive of hypertrophic subaortic stenosis. The above findings were due to the administration of dobutamine hydrochloride for hypotension in association with afterload reduction (intra‐aortic balloon pumping) and disappeared almost immediately after left ventriculography (volume load).
Noninvasive recognition of the parchment right ventricle (Uhl's anomaly arrhythmogenic right ventricular dysplasia) syndrome
Authors: Gaffney F. A. , Nicod P. , Lin J. C. , Rude R. E.
Published: January 2015

The case of a 53‐year‐old man with right heart failure, selective enlargement of the right‐sided cardiac chambers, and recurrent sustained ventricular tachycardia is presented. Echocardiographic, radionuclide ventriculographic, and angiographic studies were typical of the right ventricular abnormalities in Uhl's anomaly; electrocardiographic and electrophysiologic findings were those of arrhythmogenic right ventricular dysplasia. Features of this unusual cause of cardiac failure and ventricular arrhythmias in the adult are reviewed, and compared to previous reports of both Uhl's anomaly and arrhythmogenic right ventricular dysplasia. We postulate that these two syndromes are manifestations of a single, presumably congenital, pathophysiologic process—the “parchment right ventricle” syndrome.
Fetal cardiac structure and function as studied by ultrasound
Authors: Wladimiroff J. W. , Stewart P. A. , Vosters R. P. L.
Published: January 2015

Present combined two‐dimensional real‐time and M‐mode echocardiograph systems allow detailed analysis of fetal cardiac structure and function. Standard scanning planes for systematic investigation of various cardiac structures are described. There is a curvilinear increase in left ventricular volume (Qlv), stroke volume (Qlvs), and output Q'lv) during the last trimester of pregnancy with a mean Q'lv value at term of 126±11 ml/kg/min. Scanning for cardiac defects should preferably be done between 18 and 24 weeks of gestation. In a total of 444 patients referred to our ultrasound unit for ultrasonic analysis of fetal cardiac structure, a total of 13 cardiac defects were diagnosed. The incidence of structural cardiac defects present among those with fetal dysrhythmia was 15%.
Exercise testing in the latent phase of chagas' disease
Authors: Pereira M. H. B. , Brito F. S. , Ambrose J. A. , Pereira C. B. , Levi G. C. , Neto V. A. , Martinez E. E.
Published: January 2015

Exercise stress testing was performed in 50 completely asymptomatic patients in the latent phase of Chagas' disease. In 32 (64%) abnormalities were found consisting of either abnormal ST depression, exercise‐induced arrhythmias, or chronotropic incompetence. The latter was determined by comparing the heart rate response to 50 age‐ and sex‐matched control patients without serologic evidence of Chagas' disease. In the absence of an adequate control population we can only speculate as to the significance of the ST depression and arrhythmias during exercise. However, chronotropic incompetence may be a specific marker for Trypanosomal infestation in an endemic area. It probably is an early manifestation of autonomic dysfunction secondary to Chagas' disease.
Q‐ Versus non‐Q‐wave myocardial infarction: Clinical characteristics and 6‐month prognosis
Authors: Lekakis J. , Katsoyanni K. , Trichopoulos D. , Tsitouris G.
Published: January 2015

A prospective study of 208 consecutive survivors of acute myocardial infarction was undertaken to determine the differences between Q‐ and non‐Q‐wave infarction, concerning data from the history, clinical course, and 6‐month follow‐up. There were 177 patients with Q‐wave infarction and 31 patients with non‐Q‐wave infarction. There were no significant differences for the following variables: age, sex, diabetes mellitus, smoking, positive family history, hypertension, obesity, previous infarction, history of unstable angina, heart failure or chronic obstructive pulmonary disease (COPD), Killip class in the Coronary Care Unit (CCU), arrhythmias and conduction defects in the CCU as well as drugs used. Patients with non‐Q wave infarction had a higher incidence of stable angina before the myocardial infarction and a lower value of creatine kinase (CK) and serum glutamic oxalacetic transferase (SGOT). During the 6‐month follow‐up, 9 cardiac deaths and 17 reinfarctions occurred, while 74 patients presented angina. There were no differences between the two groups concerning the incidence of cardiac death or angina, but patients with non‐Q‐wave infarction had a higher incidence of reinfarction at 6 months (p < 0.001).

We conclude that although patients with non‐Q‐wave myocardial infarction have a lesser degree of myocardial damage, they have a high incidence of early reinfarction which puts them in a high‐risk group.
Chronic traumatic tricuspid insufficiency
Authors: Sheikhzadeh A. , Langbehn A. F. , Ghabusi P. , Hakim CH , Wendler G. , Tarbiat S.
Published: January 2015

Isolated tricuspid insufficiency (TI) is relatively uncommon and mostly of traumatic origin. We report clinical noninvasive and invasive findings and surgical results in 5 cases. All patients had complete clinical, noninvasive and invasive studies including right and left catheterization, and coronary angiographies in 3 patients. All but 1 patient had nonpenetrating trauma. All had large jugular V waves, right precordial impulse, systolic liver pulse, positive Carvallo sign documented also by noninvasive techniques. Right heart failure was present in 3 patients. Chest x‐ray showed prominent right atrium and distended vena cavae. Electrocardiogram showed normal sinus rhythm in 4 patients and atrial fibrillation in 1. Two patients had right bundle‐branch block, and 2 presented RSR'‐pattern. Echocardiogram showed large right atrium (RA) (6–10 cm), floppy tricuspid valve (TV) in all, dilated right ventricle (RV) in 2 patients. Findings of left heart were normal in all. Three patients had right‐to‐left shunt. In RA A waves were 4–8, Y waves 1–3, and V waves 12–22 mmHg, respectively (mean RV and PA pressures were 23/3 and 23/10 mmHg, respectively). Four patients had anuloplasty, 2 of them repair of valve and chordae. Surgical results were good in 2 patients with valve repair, satisfactory in 1; there was significant TI resistance in 1 case. We conclude that TI has distinctive clinical findings and must be ruled out in all patients with chest trauma. Surgery must include not only anuloplasty, but, cusps and chordae must also be evaluated and reconstructed if necessary.
Comparison of exercise blood pressure measured by technician and an automated system
Authors: Garcia‐Gregory J. A. , Jackson A. S. , Studeville J. , Squires W. G. , Owen C. A.
Published: January 2015

We evaluated the automated system Blood Pressure Measuring System (BPMS) developed by NASA on 277 adult males who elected to have a treadmill test as part of their annual physical. The BPMS uses acoustic transduction with a computer‐assisted ECG gating to detect nonsynchronous noise. The BPMS readings were compared to pressures simultaneously measured by trained technicians. For all stages of work, BPMS readings were higher for systolic and lower for diastolic than technician readings. At peak stages of work, BPMS systolic pressures were about 20 mmHg higher than technician readings. Within each 3‐min workstage, BPMS readings were found to be more inconsistent than technician readings. The standard errors of measurement for BPMS were from two to three times higher than technician values. These data showed automated blood pressure readings were significantly different than technician values and subject to more random fluctuations. These findings demonstrate the need to view exercise blood pressure measured by automated systems with caution.
Human coronary laser recanalization
Authors: Choy D. S. J. , Stertzer S. H. , Myler R. K. , Marco J. , Fournial G.
Published: January 2015

Five patients undergoing distal saphenous vein bypass had an attempt at intraoperative laser vaporization of a proximal coronary stenosis. Laser treatment of three patients was technically successful. One patient's successfully treated native vessel was competing with the graft at angiographic restudy 25 days after the procedure. This first human intraoperative laser recanalization trial generated questions regarding the energy source, power parameters, and catheter modifications required for satisfactory clinical laser therapy. The trial is directing future experiments toward more efficient and complete laser vaporization of atherosclerotic plaques in the human coronary vasculature.
Echocardiographic assessment of the inferior vena cava wall motion for studies of right heart dynamics and function
Authors: Gullace G. , Savoia M. T.
Published: January 2015

Using subcostal echocardiography, 97 patients with diseases involving the right side of the heart and 15 normal subjects were examined in order to study the inferior vena cava (IVC) wall motion. All cases had a diagnostic cardiac catheterization and routine echocardiogram. The jugular pulse (JP) was recorded in 35 random cases contemporary to the IVC and tricuspid valve (TV) tracings. The aim of the study was to evaluate the variations of the IVC diameters in different cardiopathies and in relation to the right atrial mean pressure and the time‐relationship of the IVC wall motion related to the cardiac rhythm and cycle, respiratory events, and JP and TV waves. The a, b, v, and y waves were identified on the IVC tracings and related to the respective waves of the JP and the points of closure and opening of the TV. The IVC a and v waves were coincident with the TV closure and opening, and therefore, considered as moments of maximal presystolic and systolic filling of the IVC. The JP a wave inscribed before, whereas the v wave did so after the same IVC waves, respectively. The IVC a wave was due to the atrial contraction and influenced by the cardiac rhythm. The emptying index (EI) was calculated from the diameters in a and b as a – b/a × %, whereas the collapsability index (CI) was calculated from the expiratory and inspiratory diameters as Ex – In/Ex × %, obtaining a good correlation with the right atrial mean pressure. Finally, the percentage systolic pulsation (SP) was calculated from the diameters in b and v as b – v/b × %. The indices of function of the IVC have been very useful in the evaluation of patients with raised heart pressure, tricuspid regurgitation, and pericardial effusion. From the present investigation it results that the IVC wall motion, more so than the JP waves, is an expression of right atrial and ventricular events, and that the above indices are an expression of the atrial and ventricular function in relation to the hemodynamic situation.
Spatially Distributed Current Oscillations with Electrochemical Reactions in Microfluidic Flow Cells
Authors: Bîrzu Adrian , Jia Yanxin , Sankuratri Varun , Liu Yifan , Kiss István Z.
Published: January 2015

The formation of spatiotemporal patterns is investigated by using a chemical reaction on the surface of a high‐aspect‐ratio metal electrode positioned in a flow channel. A partial differential equation model is formulated for nickel dissolution in sulfuric acid in a microfluidic flow channel. The model simulations predict oscillatory patterns that are spatially distributed on the electrode surface; the downstream portion of the metal surface exhibits large‐amplitude, nonlinear oscillations of dissolution rates, whereas the upstream portion displays small‐amplitude, harmonic oscillations with a phase delay. The features of the dynamical response can be interpreted by the dependence of local dynamics on the widely varying surface conditions and the presence of strong coupling. The patterns can be observed for both contiguous and segmented metal surfaces. The existence of spatially distributed current oscillations is confirmed in experiments with Ni electrodissolution in a microfluidic device. The results show the impact of a widely heterogeneous environment on the types of patterns of chemical reaction rates.
Efficient Exciton Harvesting through Long‐Range Energy Transfer
Authors: Wang Yanbin , Ohkita Hideo , Benten Hiroaki , Ito Shinzaburo
Published: January 2015

Efficient exciton collection at charge‐generation sites is one of the key requirements for the improvement in power conversion efficiency (PCE) of organic solar cells, because only excitons arriving at a donor/acceptor interface can be dissociated into free charge carriers. We evaluated the effective diffusion length in poly(3‐hexylthiophene) (P3HT) by using donor/acceptor bilayers with two different exciton‐quenching acceptors. One is an insoluble fullerene polymer (p‐PCBVB), which is an efficient electron‐accepting material with negligible absorption in the visible region. The other is a low‐bandgap polymer, poly[(4,4‐bis(2‐ethylhexyl)‐dithieno[3,2‐b:2′,3′‐d]silole)‐2,6‐diyl‐alt‐(2,1,3‐benzothiadiazole)‐4,7‐diyl], (PSBTBT). This polymer has a large absorption band in the near‐IR region, which overlaps well with the emission band of P3HT. The effective diffusion length of P3HT excitons is evaluated to be 15 nm for P3HT/p‐PCBVB bilayers and improved to 30 nm for P3HT/PSBTBT bilayers. This improvement is ascribed to long‐range energy transfer from P3HT to PSBTBT. This finding suggests that the effective diffusion length of P3HT excitons can be increased through long‐range energy transfer by incorporating PSBTBT into P3HT/PCBM blends.
Modeling of Nanoplasmas Created from Finite Systems by Ultrafast Intense X‐ray Pulses
Authors: Ziaja B. , Jurek Z. , Saxena V. , Santra R.
Published: January 2015

In this review we discuss various simulation methods for modeling nanoplasmas created from finite‐size samples after their irradiation with femtosecond, intense X‐ray pulses. Depending on the sample composition and its size, either a particle method or a transport method can be applied. Also, the observables of interest influence the choice of the simulation method. The current status of dedicated methods developed by the CFEL Theory Division at DESY in Hamburg and their possible extensions are presented together with some application examples. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of Nonthermal Solid‐to‐Solid Phase Transition in Diamond Irradiated with Femtosecond x‐ray FEL Pulse
Authors: Medvedev N. , Tkachenko V. , Ziaja B.
Published: January 2015

In this contribution we review in detail our recently developed hybrid model able to trace simultaneously nonequilibrium electron kinetics, evolution of an electronic structure, and eventually nonthermal phase transition in solids irradiated with femtosecond free‐electron laser pulses. Diamond irradiated with an ultrashort intense x‐ray pulse serves as an example to show how an irradiated material undergoes an ultrafast phase transition on sub‐picosecond timescales. The transition of diamond into graphite is induced by an excitation of electrons from the valence band into the conduction band, which, in turn, induces a rapid change of the interatomic potential. Our theoretical model incorporates: a Monte‐Carlo method for tracing high‐energy electrons and K‐shell holes in diamond; a temperature equation for the valence‐band and low‐energy conduction‐band electrons; a tight binding method for calculation of the evolving electronic structure of the material and potential energy surfaces; and molecular dynamics propagating atomic trajectories. This unified approach predicts the damage threshold of diamond in a good agreement with experimentally measured values. It reveals a multi‐step nature of nonthermal phase transition being an interplay between electronic excitation, changes of the band structure, and atomic reordering. An effect of pulse parameters, such as photon energy and temporal pulse shape, on the phase transition is discussed in detail. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production and Diagnostics of Dense Matter
Authors: Brambrink E. , Amadou N. , Benuzzi‐Mounaix A. , Geissel M. , Harmand M. , Pelka A. , Vinci T. , Koenig M.
Published: January 2015

High energy lasers are a unique tool to create high pressure states above 10 Mbar at ns time scales, which allow to study material properties under these extreme conditions. These conditions are, for example, comparable with planetary cores, where material properties play an important role for the properties and evolution of a planet. The rapid compression allows also to study dynamic effects of phase transitions as compression times are comparable to relaxation times. We will present recent results of laser compression of iron reaching conditions of so called “super‐Earth” cores. A description of the compression schemes as well as present and future diagnostics is presented. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equilibrium and Non‐Equilibrium Melting of Two‐Dimensional Plasma Crystals
Authors: Ivlev A.V. , Nosenko V. , Röcker T.B.
Published: January 2015

Recent progress in experimental and theoretical studies of melting of two‐dimensional (2D) plasma crystals is summarized. Several generic, equilibrium and non‐equilibrium processes which can be observed and investigated in 2D complex plasmas are discussed, such as KTHNY, grain‐boundary‐induced, and shear‐induced melting. Furthermore, the key features of the dominant plasma‐specific mechanism of melting operating in 2D plasma crystals, the mode‐coupling instability, are presented. The onset of the instability, which is characterized by threshold values of the experimental parameters, identifies the “dividing line” between the regimes when 2D complex plasmas can be employed to study generic strong‐coupling phenomena, and the situations when the melting occurs due to specific processes peculiar to complex plasmas. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of malignant mesothelioma using nuclear structure of mesothelial cells in effusion cytology specimens
Authors: Tosun Akif Burak , Yergiyev Oleksandr , Kolouri Soheil , Silverman Jan F. , Rohde Gustavo K.
Published: January 2015

Mesothelioma is a form of cancer generally caused from previous exposure to asbestos. Although it was considered a rare neoplasm in the past, its incidence is increasing worldwide due to extensive use of asbestos. In the current practice of medicine, the gold standard for diagnosing mesothelioma is through a pleural biopsy with subsequent histologic examination of the tissue. The diagnostic tissue should demonstrate the invasion by the tumor and is obtained through thoracoscopy or open thoracotomy, both being highly invasive surgical operations. On the other hand, thoracocentesis, which is removal of effusion fluid from the pleural space, is a far less invasive procedure that can provide material for cytological examination. In this study, we aim at detecting and classifying malignant mesothelioma based on the nuclear chromatin distribution from digital images of mesothelial cells in effusion cytology specimens. Accordingly, a computerized method is developed to determine whether a set of nuclei belonging to a patient is benign or malignant. The quantification of chromatin distribution is performed by using the optimal transport‐based linear embedding for segmented nuclei in combination with the modified Fisher discriminant analysis. Classification is then performed through a k‐nearest neighborhood approach and a basic voting strategy. Our experiments on 34 different human cases result in 100% accurate predictions computed with blind cross validation. Experimental comparisons also show that the new method can significantly outperform standard numerical feature‐type methods in terms of agreement with the clinical diagnosis gold standard. According to our results, we conclude that nuclear structure of mesothelial cells alone may contain enough information to separate malignant mesothelioma from benign mesothelial proliferations. © 2015 International Society for Advancement of Cytometry
Single‐cell mass cytometry reveals intracellular survival/proliferative signaling in FLT3‐ITD‐mutated AML stem/progenitor cells
Authors: Han Lina , Qiu Peng , Zeng Zhihong , Jorgensen Jeffrey L. , Mak Duncan H. , Burks Jared K. , Schober Wendy , McQueen Teresa J. , Cortes Jorge , Tanner Scott D. , Roboz Gail J. , Kantarjian Hagop M. , Kornblau Steven M. , Guzman Monica L. , Andreeff Michael , Konopleva Marina
Published: January 2015

Understanding the unique phenotypes and complex signaling pathways of leukemia stem cells (LSCs) will provide insights and druggable targets that can be used to eradicate acute myeloid leukemia (AML). Current work on AML LSCs is limited by the number of parameters that conventional flow cytometry (FCM) can analyze because of cell autofluorescence and fluorescent dye spectral overlap. Single‐cell mass cytometry (CyTOF) substitutes rare earth elements for fluorophores to label antibodies, which allows measurements of up to 120 parameters in single cells without correction for spectral overlap. The aim of this study was the evaluation of intracellular signaling in antigen‐defined stem/progenitor cell subsets in primary AML. CyTOF and conventional FCM yielded comparable results on LSC phenotypes defined by CD45, CD34, CD38, CD123, and CD99. Intracellular phosphoprotein responses to ex vivo cell signaling inhibitors and cytokine stimulation were assessed in myeloid leukemia cell lines and one primary AML sample. CyTOF and conventional FCM results were confirmed by western blotting. In the primary AML sample, we investigated the cell responses to ex vivo stimulation with stem cell factor and BEZ235‐induced inhibition of PI3K and identified activation patterns in multiple PI3K downstream signaling pathways including p‐4EBP1, p‐AKT, and p‐S6, particularly in CD34+ subsets. We evaluated multiple signaling pathways in antigen‐defined subpopulations in primary AML cells with FLT3‐ITD mutations. The data demonstrated the heterogeneity of cell phenotype distribution and distinct patterns of signaling activation across AML samples and between AML and normal samples. The mTOR targets p‐4EBP1 and p‐S6 were exclusively found in FLT3‐ITD stem/progenitor cells, but not in their normal counterparts, suggesting both as novel targets in FLT3 mutated AML. Our data suggest that CyTOF can identify functional signaling pathways in antigen‐defined subpopulations in primary AML, which may provide a rationale for designing therapeutics targeting LSC‐enriched cell populations. © 2015 International Society for Advancement of Cytometry
Diagnosis of Short‐Circuit Faults in Stator Winding Inside Low‐Voltage Induction Motor Using Impulse Voltage Test
Authors: Nakamura Hisahide
Published: January 2015

Short‐circuit faults in windings due to the deterioration of insulation is among the most common faults in motor drive systems. An easy and effective fault diagnosis method is urgently required to ensure highly reliable operation. This paper proposes a novel method for the diagnosis of short‐circuit faults in stator winding inside a low‐voltage induction motor without removing the rotor, by performing an impulse voltage test. As the rotor does not need to be removed from the motor in this novel diagnosis method, the method can be put to practical use. In this study, first, several impulse voltage tests are carried out on the stator windings of motors. Second, the values of two features that represent the characteristics corresponding to the condition of the motor are calculated, and it is found that the shape of the feature distribution does not depend on the rotor position but on the condition of the winding. Third, the distance between the feature distribution for the healthy motor and features obtained from a target motor is calculated. On the basis of this distance, the condition of the stator winding inside the induction motor is determined. The effectiveness of the proposed diagnosis method is verified by performing experiments that involve several motors with healthy and faulty windings.
Assisted Control of Step Passage Motion and Its Comfort Evaluation in Two‐Wheel Wheelchair Systems
Authors: Hirata Kazuya , Murakami Toshiyuki
Published: January 2015

Two‐wheel wheelchair systems have been attracting attention because their mobility is better than that of conventional four‐wheel wheelchair systems. However, two‐wheel wheelchair systems must achieve stabilization control in the presence of disturbances caused by modeling error or the road situation, since these systems are underactuated systems similar to the inverted pendulum. In this investigation, step passage motion in two‐wheel wheelchair systems is considered. A reaction torque observer was employed to estimate the pitch angular interaction torque and the pure external wheel disturbance. Repulsive compliance control was employed to determine the optimal pitch angle command to compensate for the center of gravity of the user and to assist the whole step passage motion. Experimental results are evaluated in terms of user comfort by utilizing the ISO 2631‐1 generalized index.
Experimental Study on Dependence of Bow‐Tie Trees on Nuclei
Authors: Kumazawa Takao , Morinaga Seiji
Published: January 2015

Bow‐tie trees (BTTs) generated by contaminants, for example, metal, amber (overcured resin), carbon, and voids in the insulators of XLPE (cross‐linked polyethylene) cables still remain a factor contributing to deterioration. In order to examine the influence of contaminants on the behavior of BTT generation, we performed several experiments using XLPE samples containing copper powder, finely divided overcured resin, or micro voids as BTT nuclei. As a result of the experiments, in spite of the great difference in the distribution of particle diameter, and the shape and permittivity of the nuclei, all samples containing copper powder or overcured resin showed a common dependence of the number of BTTs on the mean size of the BTT nuclei. Consequently, there is no fundamental difference in these nuclei. We consider that the lower limit of the nucleus size suitable for BTT generation is determined by the local electric field at the tip of the nuclei and its upper limit is determined by the extent of stagnation of ions around the nuclei. Moreover, we consider that the increase in the mean size of BTTs with the initial water content was caused by relaxation of the local electric field due to absorbed water in XLPE samples.
A Fast Outage Planning Method Focusing on Circuit Breakers Near Outage Facilities
Authors: Murakami Chihaya , Fujiwara Aya , Iwamoto Shinichi
Published: January 2015

Japanese electric power utilities installed many electric power facilities to respond to increasing power demand in the era of high economic growth. However, these facilities have aged about 40 years and should be replaced in the near future. The utilities will now have to replace larger numbers of facilities at the same time because of the increase in the number of power facilities to be replaced. Therefore, outage planning should be made more efficient. However, creating an outage plan requires time and labor, because the plan must specify (1) the outage schedule, (2) the power system configuration during outage operations, and (3) the system switching of the power system in order to conduct the outage operations. To solve these problems, a fast outage planning method focusing on circuit breakers near the outage facilities is proposed in this paper. Simulations run on IEEJ subtransmission system model I confirm the validity of the proposed method.
Clinical profile and prognostic significance of natriuretic peptide trajectory following hospitalization for worsening chronic heart failure: findings from the ASTRONAUT trial
Authors: Greene Stephen J. , Maggioni Aldo P. , Fonarow Gregg C. , Solomon Scott D. , Böhm Michael , Kandra Albert , Prescott Margaret F. , Reimund Bernard , Hua Tsushung A. , Lesogor Anastasia , Zannad Faiez , Gheorghiade Mihai ,   for the ASTRONAUT Investigators and Coordinators
Published: January 2015

Aims

The purpose of this study was to determine the prognostic significance and associated clinical profile of early post‐discharge N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) trajectory among patients hospitalized for worsening chronic heart failure (HHF).

Methods and results

This post‐hoc analysis of the Aliskiren Trial in Acute Heart Failure Outcomes (ASTRONAUT) included 1351 HHF patients with ejection fraction (EF) ≤40%, elevated B‐type natriuretic peptide ≥400 pg/mL or NT‐proBNP ≥1600 pg/mL at admission, and available NT‐proBNP measurements (from a central core laboratory) at baseline (median 5 days after admission) and 1‐month follow‐up. The co‐primary endpoints were all‐cause mortality and cardiovascular mortality or HHF within 12 months. Median follow‐up was 11.3 months. Patients with decreasing post‐discharge NT‐proBNP trajectory tended to be younger and have non‐ischaemic HF aetiology. The presence of baseline atrial fibrillation was associated with high NT‐proBNP at 1 month (i.e. above the median), regardless of the baseline value. After adjustment for patient characteristics and 1‐month NT‐proBNP level, every twofold increase in continuous NT‐proBNP change from baseline to 1 month was predictive of increased cardiovascular mortality or HHF (hazard ratio 1.14; 95% confidence interval 1.02–1.26), but not all‐cause mortality (hazard ratio 0.95; 95% confidence interval 0.81–1.11).

Conclusion

In this cohort of HHF patients with reduced EF, early post‐discharge NT‐proBNP trajectory was associated with a distinct clinical profile and carried independent prognostic value after adjustment for patient characteristics and absolute NT‐proBNP level. Future prospective study of serial NT‐proBNP measurement during the hospital and early post‐discharge periods is warranted to validate these findings and evaluate post‐discharge NT‐proBNP trajectory as a therapeutic target.
Deficiency of prolactin‐inducible protein leads to impaired Th1 immune response and susceptibility to Leishmania major in mice
Authors: Li Jintao , Liu Dong , Mou Zhirong , Ihedioha Olivia C. , Blanchard Anne , Jia Ping , Myal Yvonne , Uzonna Jude E.
Published: January 2015

Although the strategic production of prolactin‐inducible protein (PIP) at several ports of pathogen entry into the body suggests it might play a role in host defense, no study has directly implicated it in immunity against any infectious agent. Here, we show for the first time that PIP deficiency is associated with reduced numbers of CD4+ T cells in peripheral lymphoid tissues and impaired CD4+ Th1‐cell differentiation in vitro. In vivo, CD4+ T cells from OVA‐immunized, PIP‐deficient mice showed significantly impaired proliferation and IFN‐γ production following in vitro restimulation. Furthermore, PIP‐deficient mice were highly susceptible to Leishmani major infection and failed to control lesion progression and parasite proliferation. This susceptibility was associated with impaired NO production and leishmanicidal activity of PIP KO macrophages following IFN‐γ and LPS stimulation. Collectively, our findings implicate PIP as an important regulator of CD4+ Th1‐cell‐mediated immunity.
Hydrolytic Stability and Hydrogen Peroxide Activation of Zirconium‐Based Oxoclusters
Authors: Faccioli Francesco , Bauer Matthias , Pedron Danilo , Sorarù Antonio , Carraro Mauro , Gross Silvia
Published: January 2015

Invited for the cover of this issue are the groups of Silvia Gross (IENI‐CNR and University of Padova) and Mauro Carraro (University of Padova) in collaboration with Matthias Bauer (Paderborn University) and Danilo Pedron (University of Padova). The cover image shows the oxidation of organic sulfides by Zr‐based peroxides, obtained from the reaction of Zr oxoclusters with hydrogen peroxide
High Performance Liquid Chromatography/Electrochemistry/High Resolution Electrospray Ionization‐Mass Spectrometry (HPLC/EC/HR ESI‐MS) Characterization of Selected Cytokinins Oxidation Products
Authors: Karady Michal , Novák Ondřej , Horna Aleš , Strnad Miroslav , Doležal Karel
Published: January 2015

Electrochemistry combined with mass spectrometry represents an emerging analytical technique used to study the oxidation pathway of various drugs and in vivo occurring compounds, continuously showing a capability to generate many known metabolites or new oxidation products. An on‐line HPLC/EC/HR ESI‐MS method had been used to investigate the oxidation of selected cytokinin compounds. This setup allowed rapid identification and general structure elucidation of the obtained products. An electrochemical oxidation of isopentenyladenine resulted in five products, including hydroxylated and dehydrogenated products, which correlates very well with its in vivo metabolism. Electrochemical conversion of trans‐zeatin revealed six products, with two dehydrogenation products corresponding to its in vivo occurring metabolites. cis‐Zeatin oxidation in the electrochemical cell gave rise to eight products, resembling similarity to trans‐zeatin oxidation. All three compounds underwent a complete turnover mainly through two oxidation reactions occurring in the electrochemical celldehydrogenation and a less typical aliphatic hydroxylation. The resulting products are in correlation with their known in vivo metabolism.
Coating on Zinc Surface to Improve the Electrochemical Behavior of Zinc Anodes for Zinc‐Air Fuel Cells
Authors: Kim Hong Shin , Jo Yong Nam , Lee Won Jong , Kim Ki Jae , Lee Chang Woo
Published: January 2015

The corrosion of Zn anode, associated with corrosion current and hydrogen evolution reaction, is a major reason for capacity loss and safety problems. As a way of improving the current issue, a newly coating method using difference of melting points has been attempted to synthesize anode materials and found to be highly effective. Effects of corrosion inhibitors are also investigated by diverse electrochemical techniques. The Tafel extrapolation shows the reduced corrosion current compared with that of pure Zn. ZnNi‐2 (Zn:Ni, 95 : 5 wt.%) demonstrates the hydrogen overpotential is shifted to the most negative value as −1.7 V vs. Hg/HgO.
A Novel Label‐Free Immunosensor Based on Activated Graphene Oxide for Acetaminophen Detection
Authors: Tertiş Mihaela , Hosu Oana , Fritea Luminiţa , Farcau Cosmin , Cernat Andreea , Săndulescu Robert , Cristea Cecilia
Published: January 2015

A simple label‐free immunosensor for the selective detection of acetaminophen was developed by modifying a graphite based screen‐printed electrode with graphene oxide after the functionalization with N‐hydroxysuccinimide in the presence of 1‐ethyl‐3‐(3‐dimethyl aminopropyl) carbodiimide hydrochloride. The template made by layer‐by‐layer technique provides activated carboxylic groups, which form amidic covalent bonds with the terminal amine groups from the antiacetaminophen antibody. The optimization of antibody immobilization and the blocking of the free active groups from graphene template with bovine serum albumin was performed by using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The electrochemical quartz crystal microbalance technique was used to determine the quantity of different components deposited onto the electrode surface during the optimization steps. The above described immunosensor was applied with good results for the determination of acetaminophen in synthetic and real samples by using square wave voltammetry. A limit of detection of 0.17 µM (S/N=3) was obtained with no or minimal interference of dosage forms excipients and serum components.
Novel Ion‐to‐Electron Transduction Principle for Solid‐Contact ISEs
Authors: Hupa Elisa , Vanamo Ulriika , Bobacka Johan
Published: January 2015

Solid‐contact ion‐selective electrodes (SC‐ISEs) are traditionally employed as potentiometric sensors, where the ion activity is related to the zero‐current potential of the sensor versus the reference electrode. In this communication, an alternative ion‐to‐electron transduction principle for SC‐ISEs is introduced. The suggested signal transduction principle resembles “constant‐potential coulometry” utilizing the redox capacitance of the internal solid contact in order to convert changes in ion concentration (activity) into electrical current and charge. This short communication provides proof‐of‐concept for the suggested signal transduction method for SC‐ISEs utilizing poly(3,4‐ethylenedioxythiphene) (PEDOT) as the solid contact that was coated with a cation‐sensitive polymeric membrane.
New pressure‐assisted sweeping on‐line preconcentration for highly polar environmentally relevant nitrosamines: Part 2. Cationic and anionic surfactants with zero‐flow capillaries
Authors: Modir‐Rousta Ali , Bottaro Christina S.
Published: January 2015

We recently introduced a pressure‐assisted sweeping‐reversed migration‐EKC (RM‐EKC) method for preconcentration of neutral polar N‐nitrosamines with low affinity for the micellar phase. The type of surfactant and phase ratio are dominant factors in dictating the magnitude of interactions between analyte and micellar phase, thus four surfactants (anionic and cationic) with a range of functionalities (SDS, ammonium perfluorooctanoate (APFO), bile salts, and cetyltrimethylammonium chloride (CTAC)) were evaluated for sweeping‐RM‐EKC of highly polar N‐nitrosamines. All gave acceptable results for sweeping‐RM‐EKC when used in high concentrations (≥200 mM) with low EOF. While no single surfactant was superior by all measures, all but the bile salts had useful performance characteristics. APFO showed the narrowest peak widths and highest number of theoretical plates, though two species co‐migrated at all concentrations (25–300 mM); SDS and the cationic surfactant CTAC also showed good separation characteristics and could resolve all peaks, but CTAC had wider separation window. Various types of capillaries coated for EOF control were compared for use with anionic and cationic surfactants. A commercial zero‐EOF capillary coated with a polymer bearing sulfonic acid functional groups showed superior EOF suppression and reproducibility of migration time with all surfactants.
Study of immobilized metal affinity chromatography sorbents for the analysis of peptides by on‐line solid‐phase extraction capillary electrophoresis‐mass spectrometry
Authors: Ortiz‐Martin Lorena , Benavente Fernando , Medina‐Casanellas Silvia , Giménez Estela , Sanz‐Nebot Victoria
Published: January 2015

Several commercial immobilized metal affinity chromatography sorbents were evaluated in this study for the analysis of two small peptide fragments of the amyloid β‐protein (Aβ) (Aβ(1–15) and Aβ(10–20) peptides) by on‐line immobilized metal affinity SPE‐CE (IMA‐SPE‐CE). The performance of a nickel metal ion (Ni(II)) sorbent based on nitrilotriacetic acid as a chelating agent was significantly better than two copper metal ion (Cu(II)) sorbents based on iminodiacetic acid. A BGE of 25 mM phosphate (pH 7.4) and an eluent of 50 mM imidazole (in BGE) yielded a 25‐fold and 5‐fold decrease in the LODs by IMA‐SPE‐CE‐UV for Aβ(1–15) and Aβ(10–20) peptides (0.1 and 0.5 μg/mL, respectively) with regard to CE‐UV (2.5 μg/mL for both peptides). The phosphate BGE was also used in IMA‐SPE‐CE‐MS, but the eluent needed to be substituted by a 0.5% HAc v/v solution. Under optimum preconcentration and detection conditions, reproducibility of peak areas and migration times was acceptable (23.2 and 12.0%RSD, respectively). The method was more sensitive for Aβ(10–20) peptide, which could be detected until 0.25 μg/mL. Linearity for Aβ(10–20) peptide was good in a narrow concentration range (0.25–2.5 μg/mL, R2 = 0.93). Lastly, the potential of the optimized Ni(II)‐IMA‐SPE‐CE‐MS method for the analysis of amyloid peptides in biological fluids was evaluated by analyzing spiked plasma and serum samples.
Simultaneous determination of multiclass preservatives including isothiazolinones and benzophenone‐type UV filters in household and personal care products by micellar electrokinetic chromatography
Authors: Lopez‐Gazpio Josu , Garcia‐Arrona Rosa , Millán Esmeralda
Published: January 2015

In this work, a simple and reliable micellar electrokinetic chromatography method for the separation and quantification of 14 preservatives, including isothiazolinones, and two benzophenone‐type UV filters in household, cosmetic and personal care products was developed. The selected priority compounds are widely used as ingredients in many personal care products, and are included in the European Regulation concerning cosmetic products. The electrophoretic separation parameters were optimized by means of a modified chromatographic response function in combination with an experimental design, namely a central composite design. After optimization of experimental conditions, the BGE selected for the separation of the targets consisted of 60 mM SDS, 18 mM sodium tetraborate, pH 9.4 and 10% v/v methanol. The MEKC method was checked in terms of linearity, LODs and quantification, repeatability, intermediate precision, and accuracy, providing appropriate values (i.e. R2 ≥ 0.992, repeatability RSD values ˂9%, and accuracy 90–115%). Applicability of the validated method was successfully assessed by quantifying preservatives and UV filters in commercial consumer products.
Binding constant determination of uranyl–citrate complex by ACE using a multi‐injection method
Authors: Zhang Yiding , Li Linnan , Huang Hexiang , Xu Linnan , Li Ze , Bai Yu , Liu Huwei
Published: January 2015

The binding constant determination of uranyl with small‐molecule ligands such as citric acid could provide fundamental knowledge for a better understanding of the study of uranyl complexation, which is of considerable importance for multiple purposes. In this work, the binding constant of uranyl–citrate complex was determined by ACE. Besides the common single‐injection method, a multi‐injection method to measure the electrophoretic mobility was also applied. The BGEs used contained HClO4 and NaClO4, with a pH of 1.98 ± 0.02 and ionic strength of 0.050 mol/L, then citric acid was added to reach different concentrations. The electrophoretic mobilities of the uranyl–citrate complex measured by both of the two methods were consistent, and then the binding constant was calculated by nonlinear fitting assuming that the reaction had a 1:1 stoichiometry and the complex was [(UO2)(Cit)]−. The binding constant obtained by the multi‐injection method was log K = 9.68 ± 0.07, and that obtained by the single‐injection method was log K = 9.73 ± 0.02. The results provided additional knowledge of the uranyl–citrate system, and they demonstrated that compared with other methods, ACE using the multi‐injection method could be an efficient, fast, and simple way to determine electrophoretic mobilities and to calculate binding constants.
Evaluation and optimization of sample preparation methods for metabolic profiling analysis of Escherichia coli
Authors: Wang Xiyue , Yang Fengxu , Zhang Yuansheng , Xu Guowang , Liu Yang , Tian Jing , Gao Peng
Published: January 2015

In this study, exemplified by Escherichia coli, a sample preparation method was developed and evaluated with more concerns on cell pellets washing, disruption, and metabolite extraction for global metabolite profiling analysis using GC‐MS. We found that loss of some intracellular metabolites occurred inevitably, no matter which washing strategy was used. But PBS washing resulted in the least leakage of intercellular metabolites among the six tested methods. In addition, bead‐beating showed better repeatability and high throughput than sonication for cell pellet disruption. Total six extraction solvents, including chloroform/methanol/water (2:0.21:0.79, v/v/v), methyl tert‐butyl ether/methanol/water (2:0.21:0.79), acetonitrile/methanol/water (2:2:1), water/isopropanol/methanol (3:2:5), pure methanol, and methanol/water (1:1), were evaluated for metabolite extraction efficiency. We demonstrated that the numbers of extracted metabolites were almost the same, but methyl tert‐butyl ether/methanol/water and chloroform/methanol/water could achieve the best recoveries in view of MS intensities. This study implies the necessity to evaluate the potential effects of serial sample preparation procedures prior to metabolomic analysis.