bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of subgrid‐scale processes on eyewall replacement cycle of tropical cyclones in HWRF system
Authors: Zhu Ping , Zhu Zhenduo , Gopalakrishnan Sundararaman , Black Robert , Marks Frank D. , Tallapragada Vijay , Zhang Jun A. , Zhang Xuejin , Gao Cen
Published: November 2015

Two idealized simulations by the Hurricane Weather Research and Forecast (HWRF) model are presented to examine the impact of model physics on the simulated eyewall replacement cycle (ERC). While no ERC is produced in the control simulation that uses the operational HWRF physics, the sensitivity experiment with different model physics generates an ERC that possesses key features of observed ERCs in real tropical cyclones. Likely reasons for the control simulation not producing ERC include lack of outer rainband convection at the far radii from the eyewall, excessive ice hydrometeors in the eyewall, and enhanced moat shallow convection, which all tend to prevent the formation of a persistent moat between the eyewall and outer rainband. Less evaporative cooling from precipitation in the outer rainband region in the control simulation produces a more stable and dryer environment that inhibits the development of systematic convection at the far radii from the eyewall.
Methyl chloride as a tracer of tropical tropospheric air in the lowermost stratosphere inferred from IAGOS‐CARIBIC passenger aircraft measurements
Authors: Umezawa T. , Baker A. K. , Brenninkmeijer C. A. M. , Zahn A. , Oram D. E. , van Velthoven P. F. J.
Published: November 2015

We present variations of methyl chloride (CH3Cl) and nitrous oxide (N2O) in the lowermost stratosphere (LMS) obtained from air samples collected by the In‐service Aircraft for a Global Observing System‐Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container (IAGOS‐CARIBIC) passenger aircraft observatory for the period 2008–2012. To correct for the temporal increase of atmospheric N2O, the CARIBIC N2O data are expressed as deviations from the long‐term trend at the northern hemispheric baseline station Mauna Loa, Hawaii (ΔN2O). ΔN2O undergoes a pronounced seasonal variation in the LMS with a minimum in spring. The amplitude increases going deeper in the LMS (up to potential temperature of 40 K above the thermal tropopause), as a result of the seasonally varying subsidence of air from the stratospheric overworld. Seasonal variation of CH3Cl above the tropopause is similar in phase to that of ΔN2O. Significant correlations are found between CH3Cl and ΔN2O in the LMS from winter to early summer, both being affected by mixing between stratospheric air and upper tropospheric air. This correlation, however, disappears in late summer to autumn. The slope of the CH3Cl‐ΔN2O correlation observed in the LMS allows us to determine the stratospheric lifetime of CH3Cl to be 35 ± 7 years. Finally, we examine the partitioning of stratospheric air and tropical/extratropical tropospheric air in the LMS based on a mass balance approach using ΔN2O and CH3Cl. This analysis clearly indicates efficient inflow of tropical tropospheric air into the LMS in summer and demonstrates the usefulness of CH3Cl as a tracer of tropical tropospheric air.
Global adaptive regulation control for a class of nonlinear systems with unknown control coefficients
Authors: Yu Jiangbo , Lv Hongli , Wu Yuqiang
Published: November 2015

This paper is concerned with the global asymptotic regulation control problem for a class of nonlinear uncertain systems with unknown control coefficients. The allowed class of uncertainties include unmeasured input‐to‐state stable (ISS) and/or weaker integral ISS (iISS) inverse dynamics, parametric uncertainties, and uncertain nonlinearities. By using the Nussbaum‐type gain technique and changing the ISS/integral ISS inverse dynamics supply rates, we design a dynamic output feedback controller which could guarantee that the system states are asymptotically regulated to the origin from any initial conditions, and the other signals are bounded in closed‐loop systems. The numerical example of a simple pendulum with all unknown parameters and without velocity measurement illustrates our theoretical results. The simulation results demonstrate its efficacy. Copyright © 2015 John Wiley & Sons, Ltd.
Separation of azeotropic mixtures using air microbubbles generated by fluidic oscillation
Authors: Abdulrazzaq Nada , Al‐Sabbagh Baseem , Rees Julia M. , Zimmerman William B.
Published: November 2015

The feasibility of separating the azeotropic mixture of ethanol‐water using microbubble‐mediated batch distillation is presented. The effects of the depth of the liquid mixture in the bubble tank and of the inlet air microbubble temperature on the process efficiency were investigated. The enrichment of ethanol in the vapor phase was higher than that achieved at equilibrium conditions for all liquid ethanol mole fractions considered, including the azeotrope. On decreasing the depth of the liquid mixture and increasing the temperature of the air microbubbles, the separation efficiency of ethanol was improved. Ethanol with purity of about 98.2 vol % was obtained using the lowest liquid level (3 mm) in conjunction with the highest air microbubble temperature (90°C). Separation was achieved with a small rise in the temperature of the liquid mixture (4°C) at a depth of 3 mm and evaporation time of 90 min making this system suitable for treating thermally sensitive mixtures. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1192–1199, 2016
Russel–Silver syndrome: A historical note and comment on an older adult
Authors: Searle Claire , Johnson Diana
Published: November 2015

Five cases of recognizable “Intra‐uterine” dwarfism with cranio‐facial dysostosis, disproportionately short arms, and other anomalies were written up by endocrinologist, Dr. Alex Russell in 1954. The syndrome he described went on to be named Russell–Silver syndrome. This report gives further information about the life and medical history of the most pictorially documented boy that Dr. Russell originally described in his seminal paper. The gentleman is now 69 years old and we believe him to be the oldest person known to date to have Russell–Silver syndrome. The article includes information relating to his development of type 2 diabetes mellitus, osteopenia, testosterone deficiency, and hypercholesterolemia. Methylation studies have now confirmed the diagnosis of Russell–Silver syndrome by demonstrating partial hypomethylation at the H19 Locus at IGF2P0 on chromosome 11. © 2015 Wiley Periodicals, Inc.
Polyaniline benefited from poly(vinyl alcohol) in both conductivity and energy storage
Authors: Yang Liuqing , Wu Wenling , Feng Yang , Ma Yingxia , Li Shengtao , Li Yanfeng
Published: November 2015

Polyaniline (PANI) is an important conductive polymer because of its wide potential. In this article, we present a modified chemical polymerization method, which employs poly(vinyl alcohol) (PVA) as a doping assistant, for the synthesis of PANI. In this study, the introduced PVA contributed both to the conductivity and specific capacitance. The conductivity markedly increased more than two orders of magnitude from 5.2 to 1052 S/m after a small amount of PVA was introduced. A combination of the amphoteric polymer and acid together as the dopant extended the doping method for the synthesis of conductive PANI. The specific capacitance of PANI occurred up to 382.9 F/g at a current density of 0.5 A/g. The PANIs exhibited fast redox reactions, good ion response, and a short diffusion path of electronic transport. By feat of the hydrophilicity of PVA, the as‐prepared PANI showed a good dispersibility in aqueous solution; this is important for its potential applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42989.
Study of flame‐resistant acrylic fibers reinforced by poly(vinyl alcohol)
Authors: Zhou Wanli , Yan Xiang , Jiang Mengjin , Liu Pengqing , Xu Jianjun
Published: November 2015

Acrylic fibers [polyacrylonitrile (PAN) fibers] have excellent flame‐retardant properties after they are modified by hydrazine hydrate and metal ions; however, their widespread applications are restricted because of poor mechanical properties. To improve the mechanical properties of these modified PAN fibers, poly(vinyl alcohol) (PVA) was added to the spinning solution of PAN as an effective reinforcing agent. The structure of the fibers before and after modification was studied by Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive spectroscopy, and wide‐angle X‐ray diffraction. The mechanical properties and flame resistance of the fibers after treatment were also tested by a single‐fiber tensile tester and a limiting oxygen index (LOI) analyzer, respectively. We found that the LOI of the modified fibers was reduced from 54.7 to 29.1 after the introduction of 50 wt % PVA; however, the tensile strength was dramatically improved from about 1.50 cN/dtex to more than 4.00 cN/dtex. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43006.
Structure and properties relationship of melt reacted polyamide 6/malenized soybean oil
Authors: Ernzen Juliano Roberto , Bondan Fabrício , Luvison Caroline , Henrique Wanke Cesar , De Nardi Martins Johnny , Fiorio Rudinei , Bianchi Otávio
Published: November 2015

In this work, a maleinized soybean oil (SOMA) was melt reacted with polyamide 6 and the thermal, rheological, and morphological properties were evaluated. It was observed that the maleinized soybean oil reacted with polyamide chains, increasing the molecular weight of the polymer. Addition of SOMA also promoted an increase in the amount of α crystalline phase as well as in the crystallinity index. The average amorphous layer thickness (La) was enhanced with the addition of 1 wt % of SOMA, while the average crystalline layer thickness (Lc) were significantly enlarged with the increase in SOMA content, indicating that SOMA structures were located at the interfacial region between amorphous and crystalline. The addition of 5 wt % of SOMA plasticized the PA6, reducing its glass transition temperature. However, the sample containing 5 wt % of SOMA showed an accentuated pseudoplastic behavior as compared to other samples. Addition of SOMA also reduced the tensile strength and increased the elongation at break. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43050.
Affinity‐tuned peroxidase‐like activity of hydrogel‐supported Fe3O4 nanozyme through alteration of crosslinking concentration
Authors: Sang Jilong , Wu Ronglan , Guo Pingping , Du Juan , Xu Shimei , Wang Jide
Published: November 2015

In this work, we evaluated the effect of crosslinking concentration on the affinity of poly (2‐acrylamido‐2‐methyl‐1‐propansulfonic acid) (PAMPS) hydrogel‐supported Fe3O4 nanozyme towards substrates (tetramethylbenzidine (TMB) and H2O2). The peroxidase‐like catalytic activity of PAMPS/Fe3O4 nanozyme was discussed with respect to crosslinking concentration of PAMPS hydrogel for the oxidation of TMB in the presence of H2O2 at room temperature. High catalytic activity was achieved due to good dispersion of Fe3O4 nanozyme in the hydrogel network and strong affinity of PAMPS hydrogel‐supported Fe3O4 nanozyme towards substrates. The affinity between the hydrogel‐supported Fe3O4 nanozyme and substrates can be improved by regulating the crosslinking concentration of PAMPS hydrogel without other trenchant experimental conditions. In addition, the result indicated that H2O2 can be detected even at a concentration as low as 1.5 × 10−6 mol L−1 with a linear detection range of 1.5–9.8 × 10−6 mol L−1. Such investigations not only showed a new approach to improve the affinity and peroxidase‐like activity of Fe3O4 nanozyme, but also verified its potential application in bio‐detection and environmental chemistry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43065.
A highly efficient dispersant from black liquor for carbendazim suspension concentrate: Preparation, self‐assembly behavior and investigation of dispersion mechanism
Authors: Hong Nanlong , Li Yuan , Qiu Xueqing
Published: November 2015

Compared with traditional approaches using synthetic amphiphilic block copolymers, alkyl chain cross‐linked lignosulfonate (ASL) with high molecular weight (Mw) from black liquor was synthesized and characterized by GPC, functional group content, FTIR, and 1H‐NMR measurement, and then used as water soluble amphiphilic biopolymer to prepare polymersomes via solution self‐assembly. DLS illustrated the solution assembly behavior. The hollow nature of nanospheres was revealed by TEM. Moreover, the element analysis and XPS results revealed the hollow sphere structure with a hydrophilic core and a hydrophobic shell. It facilitated the efficient encapsulation of pesticide carbendazim into the hollow sphere via electrostatic interaction, which was investigated by SEM, TEM, elemental analysis and XPS. In our study, ASLs with different Mw from 20 kDa to 200 kDa all could exhibit the similar self‐assembly behavior, which suggests that the hollow spheres and the encapsulation experiment were easily duplicated from ASL polymers without structure dependence. Furthermore, the dispersion properties of ASL in the carbendazim suspension concentrate (SC) system were also investigated, which showed that SC with ASL exhibited better dispersion property and rheological performance than that of NSF and commercial LS. Preparation and application of polymersomes via self‐assembly from modified‐lignin from black liquor provide a promising and effective scaffold which can be conveniently obtained from cheap and renewable bioresource. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43067.
β‐cyclodextrin‐conjugated hyaluronan hydrogel as a potential drug sustained delivery carrier for wound healing
Authors: Li Ruicong , Zhang Xiaoting , Zhang Qiuyu , Liu Huahua , Rong Jianhua , Tu Mei , Zeng Rong , Zhao Jianhao
Published: November 2015

In order to develop a potential drug sustained delivery carrier suitable for wound healing, a series of β‐cyclodextrin conjugated hyaluronan hydrogels (β‐CD‐HA) with adjustable crosslink densities were synthesized and characterized, meanwhile the delivery kinetics and mechanism of diclofenac as a model anti‐inflammatory drug from these hydrogels were investigated. By controlling the feeding molar ratio of β‐CD/HA, a β‐CD substitution degree of 4.65% was obtained by1H‐NMR analysis. The incorporation of β‐CD modification had little effect on the internal porous structure, water swelling ratio, and rheological property of HA hydrogel, which however were influenced by the crosslink density. Although the crosslink density had an influence on the drug loading and release profile by altering the water swelling property, the interaction between β‐CD and drug was the primary factor for the high loading capacity and long‐term sustained delivery of diclofenac. The semiempirical equation fit showed that the release of diclofenac from HA‐based hydrogels followed a pseudo‐Fickian diffusion mechanism. By the aid of β‐CD and controlled crosslink density, a β‐CD‐HA hydrogel with a diclofenac sustained delivery period of over 28 days and desirable physicochemical properties was achieved, which will be a promising drug sustained delivery carrier for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43072.
Simple outlier labeling based on quantile regression, with application to the steelmaking process
Authors: Bellio Ruggero , Coletto Mauro
Published: November 2015

This paper introduces some methods for outlier identification in the regression setting, motivated by the analysis of steelmaking process data. The proposed methodology extends to the regression setting the boxplot rule, commonly used for outlier screening with univariate data. The focus here is on bivariate settings with a single covariate, but extensions are possible. The proposal is based on quantile regression, including an additional transformation parameter for selecting the best scale for linearity of the conditional quantiles. The resulting method is used to perform effective labeling of potential outliers, with a quite low computational complexity, allowing for simple implementation within statistical software as well as commonly used spreadsheets. Some simulation experiments have been carried out to study the swamping and masking properties of the proposal. The methodology is also illustrated by some real life examples, taking as the response variable the energy consumed in the melting process. Copyright © 2015 John Wiley & Sons, Ltd.
Minimization of risks in defined benefit pension plan with time‐inconsistent preferences
Authors: Zhao Qian , Wang Rongming , Wei Jiaqin
Published: November 2015

In this paper, we investigate the defined benefit pension plan, where the object of the manager is to minimise the contribution rate risk and the solvency risk by considering a quadratic performance criterion. To incorporate some well‐documented behavioural features of human beings, we consider the situation where the discounting is non‐exponential. It leads to a time‐inconsistent control problem in the sense that the Bellman optimality principle does no longer hold. In our model, we assume that the benefit outgo is constant, and the pension fund can be invested in a risk‐free asset and a risky asset whose return follows a geometric Brownian motion. We characterise the time‐consistent strategies and value function in terms of the solution of a system of integral equations. The existence and uniqueness of the solution is verified, and the approximation of the solution is obtained. Some numerical results of the equilibrium contribution rate and equilibrium investment policy are presented for three types of discount functions. Copyright © 2015 John Wiley & Sons, Ltd.
Biochemistry of the cingulate cortex in autism: An MR spectroscopy study
Authors: Libero Lauren E. , Reid Meredith A. , White David M. , Salibi Nouha , Lahti Adrienne C. , Kana Rajesh K.
Published: November 2015

Neuroimaging studies have uncovered structural and functional alterations in the cingulate cortex in individuals with autism spectrum disorders (ASD). Such abnormalities may underlie neurochemical imbalance. In order to characterize the neurochemical profile, the current study examined the concentration of brain metabolites in dorsal ACC (dACC) and posterior cingulate cortex (PCC) in high‐functioning adults with ASD. Twenty high‐functioning adults with ASD and 20 age‐and‐IQ‐matched typically developing (TD) peers participated in this Proton magnetic resonance spectroscopy (1H‐MRS) study. LCModel was used in analyzing the spectra to measure the levels of N‐Acetyl aspartate (NAA), choline (Cho), creatine (Cr), and glutamate/glutamine (Glx) in dACC and PCC. Groups were compared using means for the ratio of each metabolite to their respective Cr levels as well as on absolute internal‐water‐referenced measures of each metabolite. There was a significant increase in Cho in PCC for ASD adults, with a marginal increase in dACC. A reduction in NAA/Cr in dACC was found in ASD participants, compared to their TD peers. No significant differences in Glx/Cr or Cho/Cr were found in dACC. There were no statistically significant group differences in the absolute concentration of NAA, Cr, Glx, or NAA/Cr, Cho/Cr, and Glx/Cr in the PCC. Differences in the metabolic properties of dACC compared to PCC were also found. Results of this study provide evidence for possible cellular and metabolic differences in the dACC and PCC in adults with ASD. This may suggest neuronal dysfunction in these regions and may contribute to the neuropathology of ASD. Autism Res 2016, 9: 643–657. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.
Calculated spinal cord electric fields and current densities for possible neurite regrowth from quasi‐DC electrical stimulation
Authors: Greenebaum Ben
Published: November 2015

The prime goal of this work was to model essentially steady (DC) fields from electrodes, implanted in several ways, which have been suggested as possible means to encourage nerve fiber regrowth in spinal cord injuries. A simplified model of the human spinal cord in the lumbar region and the SEMCAD‐X computer program were used to calculate electric field and current density patterns from electrodes outside vertebrae and those inserted extradurally within the spinal canal. DC electric fields guide nerve growth in developing organisms and in vitro. They also have been shown to encourage healing of injured peripheral nerves, and application of a longitudinal field has been used in attempts to bridge spinal cord injuries. When calculated results are scaled to the experimental level used in the literature, all modeled electrodes produced fields in the spinal cord below fields needed in the literature for stimulation of spinal as well as peripheral nerve growth in vitro, in dogs, and in a published clinical human trial. The highly‐conducting cerebrospinal fluid appeared to provide effective shielding; there was also a very high degree of polarization at electrodes. Bioelectromagnetics. 36:564–575, 2015. © 2015 Wiley Periodicals, Inc.
Pharmacokinetic study of dendrobine in rat plasma by ultra‐performance liquid chromatography tandem mass spectrometry
Authors: Wang Shuanghu , Wu Haiya , Geng Peiwu , Lin Yingying , Liu Zezheng , Zhang Lijing , Ma Jianshe , Zhou Yunfang , Wang Xianqin , Wen Congcong
Published: November 2015

Dendrobine, considered as the major active alkaloid compound, has been used for the quality control and discrimination of Dendrobium which is documented in the Chinese Pharmacopoeia. In this work, a sensitive and simple ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method for determination of dendrobine in rat plasma is developed. After addition of caulophyline as an internal standard (IS), protein precipitation by acetonitrile–methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 (2.1 ×100 mm, 1.7 µm) column with acetonitrile and 0.1% formic acid as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 264.2 → 70.0 for dendrobine and m/z 205.1 → 58.0 for IS. Calibration plots were linear throughout the range 2–1000 ng/mL for dendrobine in rat plasma. The RSDs of intra‐day and inter‐day precision were both <13%. The accuracy of the method was between 95.4 and 103.9%. The method was successfully applied to pharmacokinetic study of dendrobine after intravenous administration. Copyright © 2015 John Wiley & Sons, Ltd.
Country of origin and brand image influences on perceptions of online game quality
Authors: Kim Sang Jin , Choi Yung Kyun , Kim Kyung Hoon , Liu Honglei
Published: November 2015

The authors of this study investigate online game consumption in Korea and China, the two key Asian markets, to analyze relationships among country of origin (COO), brand image, belief toward online games, and perceived game quality. Perceived game quality includes three dimensions of quality: product quality, service quality, and gratification quality. The authors survey 355 Korean and Chinese online game users and find that brand image influences quality perceptions directly or indirectly through brand belief. Compared with brand image, COO seems to have indirect and weaker effects on perceptions of game quality. The multigroup research model reveals several cross‐country differences. COO significantly affects beliefs in China but not in Korea. Brand image more highly impacts brand beliefs in Korea than it does in China. To signal superior product or service quality to Chinese users, game developers should highlight COO along with other product information. To appeal to Korean users, game developers should strengthen symbolic aspects of brand image because Koreans react more positively to brand personality, brand content, and corporate identity. Copyright © 2015 John Wiley & Sons, Ltd.
Role of GPER on proliferation, migration and invasion in ligand‐independent manner in human ovarian cancer cell line SKOV3
Authors: Yan Yan , Jiang Xueli , Zhao Ying , Wen Haixia , Liu Guoyi
Published: November 2015

G protein‐coupled estrogen receptor (GPER) is identified as a critical estrogen receptor, in addition to the classical estrogen receptors ERα and ERβ. In ERα‐negative ovarian cancer cells, our previous studies have found that estrogen stimulated cell proliferation and metastasis via GPER. However, the ligand‐independent function of GPER in ovarian cancer cells is still not clear. Herein, we describe that GPER has a co‐expression with ERα and ERβ, which are first determined in SKOV3 ovarian cancer cell line. In the absence of estrogen, GPER depletion by specific siRNA inhibits the proliferation, migration and invasion of SKOV3 cells. Whereas abrogation of ERα or ERβ by specific antagonist MPP and PHTPP has the opposite effects for stimulation of cell growth. Markedly, GPER knockdown attenuates MPP or PHTPP‐induced cell proliferation, migration and invasion. Furthermore, GPER modulates protein expression of the cell cycle critical components, c‐fos and cyclin D1 and factors for cancer cell invasion and metastasis, matrix metalloproteinase 2 (MMP‐2) and MMP‐9. These findings establish that GPER ligand‐independently stimulates the proliferation, migration and invasion of SKOV3 cells. Knockdown of GPER attenuates the progression of ovarian cancer that caused by functional loss of ERα or ERβ. Targeting GPER provides new aspect as a potential therapeutic strategy in ovarian cancer. Copyright © 2015 John Wiley & Sons, Ltd.
Morphological, Functional, and Biological Vascular Healing Response 6 Months After Drug‐Eluting Stent Implantation
Authors: Nakata Tsuyoshi , Fujii Kenichi , Fukunaga Masashi , Shibuya Masahiko , Kawai Kenji , Kawasaki Daizo , Naito Yoshiro , Ohyanagi Mitsumasa , Masuyama Tohru
Published: November 2015

Objectives

This study evaluated coronary endothelial function after the implantation of sirolimus‐eluting stents (SESs), everolimus‐eluting stents (EESs), and zotarolimus‐eluting stents (ZES) by a different methodology, and also analyzed whether optical coherence tomography (OCT) findings represent endothelial healing after stenting.

Background

It is unclear whether OCT assessment of stent strut coverage represents endothelial healing after drug‐eluting stent implantation.

Methods

Thirty patients with a left anterior descending artery lesion were randomized 1:1:1 to receive an SES, EES, or ZES. The vascular response was evaluated 6 months after stenting by three methods: the functional response by acetylcholine infusion, the morphological response by OCT, and the biological response by measuring vascular endothelial growth factor (VEGF) levels.

Results

The proportion of uncovered struts by OCT at 6 months was significantly higher in both SES and EES than in ZES. However, the vasomotor response was impaired and the VEGF level of the coronary sinus was significantly lower in SES than in EES and ZES. There were no relationships between the OCT findings and vasomotor response to acetylcholine and VEGF levels in all cohorts.

Conclusions

The vascular response at 6 months was more preserved in ZES and EES than in SES. Our results suggest that the morphological assessment with OCT may not always be used as a surrogate for functional and biological healing response after stenting. © 2015 Wiley Periodicals, Inc.
Geographical miss is associated with vulnerable plaque and increased major adverse cardiovascular events in patients with myocardial infarction
Authors: Calvert Patrick A. , Brown Adam J. , Hoole Stephen P. , Obaid Daniel R. , West Nick E.J. , Bennett Martin R.
Published: November 2015

Objectives

To determine the incidence, characteristics, and outcomes associated with geographical miss (GM) of plaque.

Background

GM describes plaques that are incompletely covered following stenting, with GM thought to be associated with worse clinical outcomes. However, the incidence and characteristics of intravascular ultrasound (IVUS)‐defined GM plaques have never been studied and the relationship between GM with both short and long‐term clinical events is unknown.

Methods

One hundred and seventy patients with stable angina (n = 100) or myocardial infarction (MI) (n = 70) underwent virtual‐histology IVUS (VH‐IVUS) prior to, and following, percutaneous coronary intervention (PCI). GM was defined as three consecutive uncovered VH frames, either proximal or distal to the stented segment with plaque burden >40%. MACE was defined as a composite of death, myocardial infarction, unplanned revascularization, or hospitalization for angina.

Results

In total, 245 plaques underwent PCI with 80 (32.7%) displaying evidence of GM (69 patients). GM was associated with increased plaque volume (p < 0.001), % necrotic core, and dense calcium (both p < 0.001) and VH‐defined thin‐cap fibroatheroma (VH‐TCFA) (p = 0.01). GM was not associated with increased periprocedural MI (p = 0.15) or inflammatory cytokine release. At follow‐up, 42 MACE occurred in 28 patients (median 1,115 days). MACE was attributable to 8/80 (10%) plaques with and 7/165 (4.2%) plaques without GM (log‐rank p = 0.11). GM was associated with increased MACE in patients presenting with MI (p = 0.015), but not for those with stable angina (p = 0.94).

Conclusions

GM is common after PCI and associated with more vulnerable plaque composition/subtype. GM may confer a worse prognosis in patients undergoing PCI for MI. © 2015 Wiley Periodicals, Inc.
Revascularization heart team recommendations as an adjunct to appropriate use criteria for coronary revascularization in patients with complex coronary artery disease
Authors: Sanchez Carlos E. , Dota Anthony , Badhwar Vinay , Kliner Dustin , Smith A.J. Conrad , Chu Danny , Toma Catalin , Wei Lawrence , Marroquin Oscar C. , Schindler John , Lee Joon S. , Mulukutla Suresh R.
Published: November 2015

Objectives

To evaluate how a comprehensive evidence‐based clinical review by a multidisciplinary revascularization heart team on treatment decisions for revascularization in patients with complex coronary artery disease using SYNTAX scores combined with Society of Thoracic Surgeons‐derived clinical variables can be additive to the utilization of Appropriate Use Criteria for coronary revascularization.

Background

Decision‐making regarding the use of revascularization for coronary artery disease has come under major scrutiny due to inappropriate overuse of revascularization. There is little data in routine clinical practice evaluating how a structured, multidisciplinary heart team approach may be used in combination with the Appropriate Use Criteria for revascularization.

Methods

From May 1, 2012 to January 1, 2015, multidisciplinary revascularization heart team meetings were convened to discuss evidence‐based management of 301 patients with complex coronary artery disease. Heart team recommendations were adjudicated with the Appropriate Use Criteria for coronary revascularization for each clinical scenario using the Society for Cardiovascular Angiography and Interventions' Quality Improvement Toolkit (SCAI‐QIT) Appropriate Use Criteria App.

Results

Concordance of the Heart Team to Appropriate Use Criteria had a 99.3% appropriate primary indication for coronary revascularization. Among patients who underwent percutaneous revascularization, 34.9% had an inappropriate or uncertain indication as recommended by the Heart Team. Patients with uncertain or inappropriate percutaneous coronary interventions had significantly higher SYNTAX score (27.3 ± 6.6; 28.5 ± 5.5; 19.2 ± 6; P < 0.0001) and Society of Thoracic Surgeons‐Predicted Risk of Mortality (6.1% ± 4.7%; 8.1% ± 6.3%; 3.7% ± 4.1%; P < 0.0081) compared to appropriate indications, frequently had concomitant forms of advanced comorbidities and frailty in the setting of symptomatic coronary artery disease.

Conclusions

A formal, multidisciplinary revascularization heart team can provide proper validation for clinical decisions and should be considered in combination with the Appropriate Use Criteria for coronary revascularization to formulate revascularization strategies for individuals in a patient‐centered fashion. © 2015 Wiley Periodicals, Inc.
Predictors of survival following trans‐catheter aortic valve closure for left ventricular assist device associated aortic insufficiency
Authors: Retzer Elizabeth M. , Sayer Gabriel T. , Fedson Savitri E. , Nathan Sandeep , Jeevanandam Valluvan , Friant Janet , Uriel Nir , Lang Roberto M. , Russo Mark J. , Shah Atman P.
Published: November 2015

Objective

This study sought to assess the long‐term clinical benefits and predictors of survival of trans‐catheter aortic valve closure in left ventricular assist device (LVAD) patients.

Background

LVADs have been shown to increase survival and quality of life in patients with end‐stage heart failure. However, severe aortic insufficiency (AI) can develop in up to 50% of patients at 12 months resulting in significant morbidity and mortality. Trans‐catheter treatment of LVAD associated AI has emerged as a potential alternative to surgical treatment.

Methods

We conducted a retrospective analysis of all patients undergoing trans‐catheter aortic valve closure using an Amplatzer Multi‐Fenestrated Septal Occluder “Cribriform” device to assess potential clinical and procedural factors associated with survival. Student's t‐tests were used to compare baseline patient demographics and procedural characteristics, as well as patient outcomes immediately post procedure and at 6 months. A P‐value of less than 0.05 was considered statistically significant.

Results

A total of 10 patients (70% male, median age 59 years) were included. Technical success was accomplished in 100% of patients with a 6 month survival rate of 30% (3/10). Compared with survivors, non‐survivors had a higher rate of pre‐procedural clinical co‐morbidities, an increased likelihood of right ventricular failure, and received larger occluder devices.

Conclusions

Trans‐catheter aortic valve closure successfully treats late severe AI in LVAD patients, however, the presence or development of right heart failure portends a worse prognosis. Further studies are needed to investigate the factors involved in the development of right ventricular failure, and potential treatment, in patients undergoing trans‐catheter aortic valve closure. © 2015 Wiley Periodicals, Inc.
Comparison of simplified and comprehensive methods for assessing the index of microvascular resistance in heart transplant recipients
Authors: Geir Solberg Ole , Aaberge Lars , Ragnarsson Asgrimur , Aas Marit , Endresen Knut , Šaltytė Benth Jūratė , Gullestad Lars , Stavem Knut
Published: November 2015

Objectives

The objectives of the present study were to compare a simplified and a comprehensive method of estimating the index of microvascular resistance (IMR) and assess the changes from 7–11 weeks to 1 year after heart transplant (HTx).

Background

he IMR is specific to the microvasculature and reflects the status of the microcirculation in cardiac patients and can be estimated via a simplified method (IMRs) or a comprehensive method (IMRc). The calculation for the latter includes coronary wedge pressure and central venous pressure.

Methods

Consecutively transplanted patients (n = 48) underwent left and right heart catheterization including physiological evaluation at two time points post‐HTx. The agreement between the values of IMR obtained using the IMRs and IMRc methods were assessed using Bland–Altman analysis. The agreements and differences were assessed using mixed model analysis.

Results

The mean bias between IMRs and IMRc was 1.3 mm Hg·s (95% limits of agreement: −1.2, 3.8 mm Hg). Between 7–11 weeks and 1 year post‐HTx there was a significant decline in IMRs values (P = 0.03) but a smaller and statistically nonsignificant decline in IMRc values (P = 0.13). The significant difference (P = 0.04) between IMRc and IMRs 7–11 weeks post‐HTx was no longer present at 1 year (P = 0.24).

Conclusions

The IMRs method resulted in slightly higher IMR estimates and exhibited a somewhat larger change over the 10‐month follow‐up period than the IMRc method. However, the differences between the methods were small and unlikely to be of clinical importance. © 2015 Wiley Periodicals, Inc.
Rotational atherectomy before paclitaxel‐eluting stent implantation in complex calcified coronary lesions: Two‐year clinical outcome of the randomized ROTAXUS trial
Authors: de Waha Suzanne , Allali Abdelhakim , Büttner Heinz‐Joachim , Toelg Ralph , Geist Volker , Neumann Franz‐Josef , Khattab Ahmed A. , Richardt Gert , Abdel‐Wahab Mohamed
Published: November 2015

Background

In the randomized ROTAXUS trial, routine lesion preparation of complex calcified coronary lesions using rotational atherectomy (RA) prior to paclitaxel‐eluting stent implantation did not reduce the primary endpoint of angiographic late lumen loss at 9 months compared to stenting without RA. So far, no long‐term data of prospective head‐to‐head comparisons between both treatment strategies have been reported.

Methods and Results

ROTAXUS randomly assigned patients with complex calcified coronary lesions to RA followed by stenting (n = 120) or stenting without RA (n = 120). The primary endpoint of the current analysis was the occurrence of major adverse cardiac events (MACE) at 2‐year follow‐up defined as the composite of death, myocardial infarction, and target vessel revascularization (TVR). At 2 years, MACE occurred in 32 patients in the RA group and 37 patients in the standard therapy group (29.4% vs. 34.3%, P = 0.47). The rates of death (8.3% vs. 7.4%, P = 1.00), myocardial infarction (8.3% vs. 6.5%, P = 0.80), target lesion revascularization (TLR, 13.8% vs. 16.7%, P = 0.58), and TVR (19.3% vs. 22.2%, P = 0.62) were similar in both groups.

Conclusion

Despite high rates of initial angiographic success, nearly one third of patients enrolled in ROTAXUS experienced MACE within 2‐year follow‐up, with no differences between patients treated with or without RA. © 2015 Wiley Periodicals, Inc.
Completeness of revascularization and its impact on the outcomes of a staged approach of percutaneous coronary intervention followed by minimally invasive valve surgery for patients with concomitant coronary artery and valvular heart disease
Authors: Pineda Andrés M. , Chandra Ramesh , Gowani Saqib A. , Santana Orlando , Mihos Christos G. , Kirtane Ajay J. , Stone Gregg W. , Kurlansky Paul , Smith Craig R. , Beohar Nirat
Published: November 2015

Background

A staged approach of percutaneous coronary intervention (PCI) followed by minimally invasive valve surgery (MIVS) is an alternative to the conventional combined coronary artery bypass and valve surgery for patients with concomitant coronary artery and valve disease. Limited data exist on degree of the completeness of revascularization achieved with this approach and its impact on outcomes.

Methods

A total of 138 patients, who underwent a staged approach between January 2009 and June 2013, were retrospectively evaluated. Coronary angiograms were reviewed by two cardiologists blinded to outcomes and were then categorized into two groups: complete or incomplete revascularization, which was defined as ≥1 major epicardial coronary arteries of at least 2.0 mm diameter with ≥70% untreated obstruction after the index PCI and before MIVS.

Results

Complete and incomplete revascularization was achieved in 105 (76%) and 33 (24%) patients, respectively. The patients with incomplete revascularization had a lower ejection fraction, a higher STS score, and more prior myocardial infarctions and multi‐vessel coronary artery disease. There were no differences in the post‐operative complications, 30‐day mortality, or 3‐year survival (84 vs. 83%, P = 0.68). After a median follow‐up of 29 months, incompletely revascularized patients had a higher incidence of acute coronary syndrome (2.9 vs. 12.9%, P = 0.05).

Conclusions

In patients undergoing a staged approach of PCI followed by MIVS, incomplete revascularization did not significantly impact the short or mid‐term survival, but was associated with an increased incidence of acute coronary syndrome at follow‐up. © 2015 Wiley Periodicals, Inc.
Aortic regurgitation following transcatheter aortic valve replacement: Impact of preprocedural left ventricular diastolic filling patterns on late clinical outcomes
Authors: Halkin Amir , Steinvil Arie , Aviram Galit , Biner Simon , Banai Shmuel , Keren Gad , Finkelstein Ariel , Topilsky Yan
Published: November 2015

Objectives

To investigate the impact of preprocedural left ventricular (LV) diastolic function on outcomes of patients with postprocedural aortic regurgitation (ARpost) following transcatheter aortic valve replacement (TAVR).

Background

The predictors and mechanisms of the increased mortality in patients with ARpost are inadequately defined.

Methods

Baseline clinical and echocardiographic variables from a prospective TAVR registry were analyzed. Preprocedural correlates of late outcomes (all‐cause mortality and the composite of mortality, stroke, heart failure, and new‐onset atrial fibrillation) were examined according to the presence and severity of ARpost.

Results

Of the 418 patients undergoing TAVR, ARpost was present in 212 (51%): mild 36%, moderate–severe 15%. Mean follow‐up was 909 ± 489 days. All‐cause mortality and composite endpoint rates were significantly increased in patients with moderate–severe ARpost compared with patients with either none or only mild ARpost (38, 22, 21%, P = 0.02; and, 56, 35, 40%, P = 0.01; respectively). Moderate–severe (though not mild) ARpost was independently associated with mortality and the composite endpoint (HR = 1.93 [95%CI 1.15–3.14], P = 0.01; HR = 1.85 [95%CI 1.22–2.77], P = 0.004], respectively). By multivariate analysis, preprocedural LV deceleration time (DT) < 160 ms was independently associated with the risk of all‐cause mortality and the composite endpoint among patients with mild AR (HR = 1.74 [95%CI 1.14–2.60], P = 0.01; and, HR = 1.73 [95%CI 1.23–2.41], P = 0.002, respectively) and moderate–severe ARpost (HR = 1.81 [95%CI 1.28–2.51], P < 0.001; HR = 1.86 [95%CI 0.22–2.80], P = 0.004, respectively).

Conclusions

Preprocedural impairment of LV filling, reflected by short DT, portends an adverse prognosis in TAVR patients who develop ARpost independently of other clinical and echocardiocardigraphic measures including AS severity and systolic LV function. © 2015 Wiley Periodicals, Inc.
CRISP: Catheterization RISk score for pediatrics: A Report from the Congenital Cardiac Interventional Study Consortium (CCISC)
Authors: Nykanen David G. , Forbes Thomas J. , Du Wei , Divekar Abhay A. , Reeves Jaxk H. , Hagler Donald J. , Fagan Thomas E. , Pedra Carlos AC , Fleming Gregory A. , Khan Danyal M. , Javois Alexander J. , Gruenstein Daniel H. , Qureshi Shakeel A. , Moore Phillip M. , Wax David H. ,   For the Congenital Cardiac Interventional Study Consortium (CCISC)
Published: November 2015

Objectives

We sought to develop a scoring system that predicts the risk of serious adverse events (SAE's) for individual pediatric patients undergoing cardiac catheterization procedures.

Background

Systematic assessment of risk of SAE in pediatric catheterization can be challenging in view of a wide variation in procedure and patient complexity as well as rapidly evolving technology.

Methods

A 10 component scoring system was originally developed based on expert consensus and review of the existing literature. Data from an international multi‐institutional catheterization registry (CCISC) between 2008 and 2013 were used to validate this scoring system. In addition we used multivariate methods to further refine the original risk score to improve its predictive power of SAE's. Results: Univariate analysis confirmed the strong correlation of each of the 10 components of the original risk score with SAE attributed to a pediatric cardiac catheterization (P < 0.001 for all variables). Multivariate analysis resulted in a modified risk score (CRISP) that corresponds to an increase in value of area under a receiver operating characteristic curve (AUC) from 0.715 to 0.741.

Conclusion

The CRISP score predicts risk of occurrence of an SAE for individual patients undergoing pediatric cardiac catheterization procedures. © 2015 Wiley Periodicals, Inc.
Complete Versus Culprit‐Only Revascularization for Patients With Multi‐Vessel Disease Undergoing Primary Percutaneous Coronary Intervention: An Updated Meta‐Analysis of Randomized Trials
Authors: Elgendy Islam Y. , Wen Xuerong , Mahmoud Ahmed , Bavry Anthony A.
Published: November 2015

Objectives

To perform an updated meta‐analysis to determine whether complete revascularization of significant coronary lesions at the time of primary percutaneous coronary intervention (PCI) would be associated with better outcomes compared with culprit‐only revascularization.

Background

Individual trials have demonstrated conflicting evidence regarding the optimum revascularization strategy at the time of primary PCI.

Methods

Clinical trials that randomized ST elevation myocardial infarction (STEMI) patients with multi‐vessel disease to a complete versus culprit‐only revascularization strategy were included. Random effects summary risk ratios (RR) were constructed using a DerSimonian–Laird model. The primary outcome of interest was mortality or myocardial infarction (MI).

Results

A total of seven trials with 1,939 patients were included in the analysis. Compared with culprit‐only revascularization, complete revascularization was associated with a non‐significant reduction in the risk of mortality or MI (RR 0.69, 95% confidence interval (CI) 0.42–1.12, P = 0.14). Complete revascularization was associated with a reduced risk of major adverse cardiac events (MACE) (RR 0.61, 95% CI 0.45–0.81, P < 0.001), due to a significant reduction in urgent revascularization (RR 0.46, 95% CI 0.29–0.70, P < 0.001). The risk of major bleeding and contrast‐induced nephropathy was similar with both approaches (RR 0.83, 95% CI 0.41–1.71, P = 0.62, and RR 0.94, 95% CI 0.42–2.12, P = 0.82).

Conclusions

Complete revascularization of all significant coronary lesions at the time of primary PCI was associated with a reduction in the risk of MACE due to reduction in the risk of urgent revascularization. This approach appears to be safe, with no excess major bleeding, or contrast‐induced nephropathy. © 2015 Wiley Periodicals, Inc.