bluuebunny/crossref_metadata_2025 huggingface dataset:
A new four‐plasma categorization scheme for the solar wind
Authors: Xu Fei , Borovsky Joseph E.
Published: December 2014

A three‐parameter algebraic scheme is developed to categorize the solar wind at 1 AU into four plasma types: coronal‐hole‐origin plasma, streamer‐belt‐origin plasma, sector‐reversal‐region plasma, and ejecta. The three parameters are the proton‐specific entropy Sp = Tp/np2/3, the proton Alfvén speed vA, and the proton temperature Tp compared with a velocity‐dependent expected temperature. Four measurements are needed to apply the scheme: the proton number density np, the proton temperature Tp, the magnetic field strength B, and the solar wind speed vsw. The scheme is tested and is found to be more accurate than existing categorization schemes. The categorization scheme is applied to the 1963–2013 OMNI2 data set spanning four solar cycles and to the 1998–2008 ACE data set. The statistical properties of the four types of plasma are examined. The sector‐reversal‐region plasma is found to have statistically low alpha‐to‐proton density ratios and high Alfvén Mach numbers. The statistical relations between the proton and alpha‐particle‐specific entropies and oxygen and carbon charge‐state‐density ratios Sp, Sα, O7+/O6+, and C6+/C5+ from ACE are examined for the four types of plasma: the patterns observed imply a connection between sector‐reversal‐region plasma and ejecta and a connection between streamer‐belt‐origin plasma and coronal‐hole‐origin plasma. Plasma occurrence rates are examined and solar cycle patterns are found for ejecta, for coronal‐hole‐origin plasma, and for sector‐reversal‐region plasma.
X‐ray imaging of Kelvin‐Helmholtz waves at the magnetopause
Authors: Sun T. R. , Wang C. , Wei F. , Sembay S.
Published: December 2014

This paper simulates the Kelvin‐Helmholtz wave (KHW)‐induced X‐ray emissions at the low‐latitude magnetopause based on a global MHD code. A method is proposed to extract the KHW information from the X‐ray intensity measured by a hypothetical X‐ray telescope onboard a satellite assumed with a low Earth orbit. Specifically, the X‐ray intensity at high latitude is subtracted from the intensity map as a background to highlight the role of KHW. Using this method, global features of KHW such as the vortex velocity, perturbation degree, spatial distribution, and temporal evolution could be evaluated from the X‐ray intensity map. The validity of this method during intervals of solar wind disturbances is also verified. According to the simulation results, X‐ray imaging of KHW is suggested as a promising observation technique to essentially “see” the large‐scale configuration and evolution of KHW for the first time.
Impact of velocity correlation and distribution on transport in fractured media: Field evidence and theoretical model
Authors: Kang Peter K. , Le Borgne Tanguy , Dentz Marco , Bour Olivier , Juanes Ruben
Published: December 2014

Flow and transport through fractured geologic media often leads to anomalous (non‐Fickian) transport behavior, the origin of which remains a matter of debate: whether it arises from variability in fracture permeability (velocity distribution), connectedness in the flow paths through fractures (velocity correlation), or interaction between fractures and matrix. Here we show that this uncertainty of distribution‐ versus correlation‐controlled transport can be resolved by combining convergent and push‐pull tracer tests because flow reversibility is strongly dependent on velocity correlation, whereas late‐time scaling of breakthrough curves is mainly controlled by velocity distribution. We build on this insight, and propose a Lagrangian statistical model that takes the form of a continuous time random walk (CTRW) with correlated particle velocities. In this framework, velocity distribution and velocity correlation are quantified by a Markov process of particle transition times that is characterized by a distribution function and a transition probability. Our transport model accurately captures the anomalous behavior in the breakthrough curves for both push‐pull and convergent flow geometries, with the same set of parameters. Thus, the proposed correlated CTRW modeling approach provides a simple yet powerful framework for characterizing the impact of velocity distribution and correlation on transport in fractured media.
Handheld Raman Spectrometers and Their Applications
Authors: Hargreaves Michael D.
Published: December 2014

Raman spectroscopy is a globally adopted technology for identification of unknown solids and liquids, spanning a huge range of applications, some of which are covered in this article. The continuing development and realization of handheld, ruggedized instruments are continuing to have a big impact on end‐users' ability to conduct field‐based, in‐situ analysis, allowing identification and verification of samples. Fifteen years ago, it was thought to be very challenging and prohibitively expensive to miniaturize Raman spectrometers into portable or handheld devices that would be of benefit to users. In just a short time, however, several generations of devices have been developed and are now routinely deployed into the field. These instruments have been at the forefront of cutting edge technologies and have been made progressively smaller, easier to use and more intelligent. Further advances in the next few years will push the capabilities even further, both in terms of the hardware and the software design and implementation.
Approximation Algorithms for Stochastic Optimization Problems in Operations Management
Authors: Shi Cong
Published: December 2014

This article provides an introduction to approximation algorithms in stochastic optimization models arising in various application domains, including central areas of operations management, such as scheduling, facility location, vehicle routing problems, inventory and supply chain management, and revenue management. Unfortunately, these models are very hard to solve to optimality in both theory and practice. We will survey recent development on approximation algorithms for these stochastic optimization models and their performance analysis techniques with worst‐case performance guarantees.
Hydrogen Fuel Cells for Auxiliary Power Units
Authors: Freeh Joshua E.
Published: December 2014

The prospect of replacing the existing aircraft gas turbine auxiliary power unit (APU) with a fuel cell system is discussed. Both solid oxide and proton exchange membrane fuel cell system solutions are reviewed, with the focus on hybrid solid oxide fuel cell/gas turbine systems. The hybrid system is projected to reduce ground NOxemissions by half, along with reducing other emissions, noise, and fuel use by significant amounts. There are still challenges with the technology, including increased mass, volume, and cost compared with current gas turbine systems. Other challenges include sufficiently processed jet fuel or adding a second fuel such as hydrogen into the aircraft system. While more progress with each of the major subsystems is needed to make the fuel cell APU system a reality, subscale demonstrations and novel approaches such as distributed systems can help accelerate this technology.
UAVSwarms: Decision‐Making Paradigms
Authors: Shin Hyo‐Sang , Segui‐Gasco Pau
Published: December 2014

The operation of UAV swarms has attracted great attention as their coordination and cooperation could bring significant impact in both military and civilian applications. Despite this potential, there are key challenges to be addressed to enable UAV swarm operations. Unlike operations of a small number of aerial vehicles, the onboard decision‐making responsibility may be more favorably distributed across the UAV swarm taking into account their scalability and sustainability. This chapter addresses three main issues of UAV technologies enabling onboard decision‐making: task allocation, communication network connectivity, and guidance and control in UAV swarm operations. Moreover, state‐of‐the‐art propositions to solve these issues and their limitations are discussed. This chapter also emphasizes the need for a new decision‐making paradigm for more efficient and effective UAV swarm operations and shows its future direction.
Design of the Space Shuttle Flight Control System and Applicability in Future Space Vehicle Development
Authors: Douglas Matthew J.I.
Published: December 2014

The Space Shuttle flight control system (FCS) provides a useful case study into how a suitably fault‐tolerant digital fly‐by‐wire (DFBW) FCS was implemented in a highly complex, innovative, and experimental space vehicle at a time when digital flight control was in its infancy. Through the use of quad‐redundant flight computers and a standby backup flight system (BFS), the necessary fault tolerance and redundancy levels were achieved within the Space Shuttle FCS for the varied and complex flight regimes it was required to manage. As several commercial space vehicles such as the Sierra Nevada Corporation Dream Chaser, the XCOR Lynx, and the Scaled Composites WhiteKnight II are in development and are due to begin operations over the next 2–4 years, it is of value to understand the design of the Space Shuttle FCS and how the problem of fault tolerance and redundancy management can be applied to the FCS design of this next generation of commercial space vehicles. Using a systems engineering framework, this chapter evaluates the design of the Space Shuttle FCS and how it is a useful basis for future space vehicle FCS development.
Vibration‐Induced Deagglomeration and Shear‐Induced Alignment of Carbon Nanotubes in Air
Authors: Miansari Morteza , Qi Aisha , Yeo Leslie Y. , Friend James R.
Published: December 2014

Carbon nanotubes (CNTs) are widely known to agglomerate into difficult to separate, 10–100 μm bundles, even after suspension in solution. Here, a dry and rapid (≈10 s) method to deagglomerate bulk, unbound multi‐walled CNT bundles due to surface acoustic waves (SAW) in a piezoelectric substrate is reported for the first time. The process first forms 1‐μm CNT bundles from extremely large (≈10 Mm/s2) mechanical accelerations due to the SAW; these bundles are consequently susceptible to SAW‐induced evanescent, quasistatic electric fields that couple into the bundles and form a mat of long (1–10 μm) individual CNTs on the substrate surface. These CNTs may then be aligned along the direction of shear provided by sliding a glass cover slip 10 mm across the CNT mat. This alignment is notably independent of the SAW propagation direction. Further, the intrinsic structure of the nanotubes is unaffected as verified using Raman spectroscopy. Uniquely simple, the approach avoids the many shortcomings of other CNT deagglomeration techniques—particularly surface modification and suspension in solution—to rapidly separate and align large numbers of CNTs, thereby overcoming a key limitation in their use for a diverse range of applications.
Controlling Polymorphism in Poly(3‐Hexylthiophene) through Addition of Ferrocene for Enhanced Charge Mobilities in Thin‐Film Transistors
Authors: Smith Brandon H. , Clark Michael B. , Kuang Hao , Grieco Christopher , Larsen Alec V. , Zhu Chenhui , Wang Cheng , Hexemer Alexander , Asbury John B. , Janik Michael J. , Gomez Enrique D.
Published: December 2014

Crystalline organic molecules often exhibit the ability to assemble into multiple crystal structures depending on the processing conditions. Exploiting this polymorphism to optimize molecular orbital overlap between adjacent molecules in the unit lattice is an effective method for improving charge transport within the material. In this study, grazing incident X‐ray diffraction was employed to demonstrate the formation of tighter π‐π stacking poly(3‐hexylthiophene‐2,5‐diyl) polymorphs in films spin coated from ferrocene‐containing solutions. As a result, the addition of ferrocene to casting solutions yields thin‐film transistors which exhibit approximately three times higher source‐drain currents and charge mobilities than neat polymer devices. Nevertheless, XPS depth profiling and NMR analyses of the active layer reveal that all ferrocene is removed during the spin coating process, which may be an essential factor to achieve high mobilities. Such insights gleaned from ferrocene/poly(3‐hexylthiophene‐2,5‐diyl) mixtures can serve as a template for selection and optimization of other small molecule/polymer systems with greater baseline charge mobilities.
Orthogonal Molecular Structure for Better Host Material in Blue Phosphorescence and Larger OLED White Lighting Panel
Authors: Ding Lei , Dong Shou‐Cheng , Jiang Zuo‐Quan , Chen Hua , Liao Liang‐Sheng
Published: December 2014

High‐efficiency blue phosphorescence devices with external quantum efficiencies above 25% are developed using a new bipolar host material, diphenyl(10‐phenyl‐10H‐spiro[acridine‐9,9′‐fluoren]‐2′‐yl)phosphine oxide (POSTF), which is constructed in orthogonal molecular structure with a spiro‐coree. The separation of bipolarity from effective spiro‐fluorene‐triphenylamine (STF) structure is elucidated and its versatility in device is evaluated by two kinds of sky‐blue phosphors. Noticeably, large‐size white light‐emitting panel (150 mm × 150 mm) is fabricated with max power efficiency of 75.9 l m W−1 using this new host.
Toward more cost‐effective and greener chemicals production from shale gas by integrating with bioethanol dehydration: Novel process design and simulation‐based optimization
Authors: He Chang , You Fengqi
Published: December 2014

A novel process design for a more cost‐effective, greener process for making chemicals from shale gas and bioethanol is presented. The oxidative coupling of methane and cocracking technologies are considered for converting methane and light natural gas liquids, into value‐added chemicals. Overall, the process includes four process areas: gas treatment, gas to chemicals, methane‐to‐ethylene, and bioethanol‐to‐ethylene. A simulation‐optimization method based on the NSGA‐II algorithm for the life cycle optimization of the process modeled in the Aspen HYSYS is developed. An energy integration model is also fluidly nested using the mixed‐integer linear programming. The results show that for a “good choice” optimal design, the minimum ethylene selling price is $655.1/ton and the unit global‐warming potential of ethylene is 0.030 kg CO2‐eq/kg in the low carbon shale gas scenario, and $877.2/ton and 0.360 kg CO2‐eq/kg in the high carbon shale gas scenario. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1209–1232, 2015
Rhodium(III)‐katalysierte Abfangcyclisierung zu vielfältigen 1‐Aminoindolinderivaten bei Raumtemperatur
Authors: Zhao Dongbing , Vásquez‐Céspedes Suhelen , Glorius Frank
Published: December 2014

Wir stellen eine RhIII‐katalysierte C‐H‐Aktivierung/Abfangcyclisierung vor, an der eine nukleophile Addition einer C(sp3)‐Rh‐Spezies an polarisierte Doppelbindungen beteiligt ist. Dies ist die erste intermolekulare katalytische Methode zur direkten Synthese von 1‐Aminoindolinen mit großer Substratbreite und unter milden Reaktionsbedingungen.
Total Synthesis of the Tiacumicin B (Lipiarmycin A3/Fidaxomicin) Aglycone
Authors: Glaus Florian , Altmann Karl‐Heinz
Published: December 2014

Tiacumicin B (lipiarmycin A3, fidaxomicin) is an atypical macrolide antibiotic which is used for the treatment of Clostridium difficile infections. Tiacumicin B is also a potent inhibitor of Mycobacterium tuberculosis, but due to its limited oral bioavailability is unsuitable for systemic therapy. To provide a basis for structure–activity studies that might eventually lead to improved variants of tiacumicin B, we have developed an efficient approach to the synthesis of the tiacumicin B aglycone. The synthesis features a high‐yielding intramolecular Suzuki cross‐coupling reaction to effect macrocyclic ring closure. Key steps in the synthesis of the macrocyclization precursor were a highly selective, one‐pot Corey–Peterson olefination and an ene–diene cross‐metathesis reaction. Depending on the reaction conditions, the final deprotection delivered either the fully deprotected tiacumicin B aglycone or partially protected versions thereof.
CO Extrusion in Homogeneous Gold Catalysis: Reactivity of Gold Acyl Species Generated through Water Addition to Gold Vinylidenes
Authors: Bucher Janina , Stößer Tim , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: December 2014

Herein, we describe a new gold‐catalyzed decarbonylative indene synthesis. Synergistic σ,π‐activation of diyne substrates leads to gold vinylidene intermediates, which upon addition of water are transformed into gold acyl species, a type of organogold compound hitherto only scarcely reported. The latter are shown to undergo extrusion of CO, an elementary step completely unknown for homogeneous gold catalysis. By tuning the electronic and steric properties of the starting diyne systems, this new reactivity could be exploited for the synthesis of indene derivatives in high yields.
Lupus Nephritis: Glycogen Synthase Kinase 3β Promotion of Renal Damage Through Activation of the NLRP3 Inflammasome in Lupus‐Prone Mice
Authors: Zhao Jijun , Wang Hongyue , Huang Yuefang , Zhang Hui , Wang Shuang , Gaskin Felicia , Yang Niansheng , Fu Shu Man
Published: December 2014

Objective

Glycogen synthase kinase 3β (GSK‐3β) has been demonstrated to be involved in immune and inflammatory responses via multiple signaling pathways, leading to the production of proinflammatory cytokines. The purpose of this study was to investigate the role of GSK‐3β in the pathogenesis of lupus nephritis in 2 mouse models.

Methods

Thiadiazolidinone 8 (TDZD‐8), a selective inhibitor of GSK‐3β, was administered intraperitoneally to 12‐week‐old MRL/lpr mice for 8 weeks or to 22‐week‐old (NZB × NZW)F1 mice for 12 weeks. The expression of GSK‐3β and NLRP3 inflammasome components was analyzed. Proteinuria, biochemical parameters, proinflammatory cytokines, anti–double‐stranded DNA (anti‐dsDNA) antibody levels, and renal pathology were examined. In vitro, the effect of GSK‐3β–directed small interfering RNA (siRNA) on NLRP3 inflammasome activation was evaluated in bone marrow–derived macrophages (BMMs) from the mice and in the J774A.1 macrophage cell line.

Results

The incidence of severe proteinuria and renal inflammation was significantly attenuated in both models, with a significant reduction in anti‐dsDNA antibody production, immune complex deposition in the kidney, and circulating proinflammatory cytokine levels. TDZD‐8 inhibited the activation of GSK‐3β and caspase 1, with a concomitant decrease in interleukin‐1β (IL‐1β) synthesis. In vitro, GSK‐3β siRNA transfection of mouse BMMs and the J774A.1 cell line with GSK‐3β siRNA inhibited the expression of GSK‐3β, the activation of caspase 1, and the production of IL‐1β.

Conclusion

These results show that GSK‐3β promotes lupus nephritis at least partly by activating the NLRP3/IL‐1β pathway. The linking of GSK‐3β to the NLRP3/IL‐1β pathway is a novel observation in our study. Our results suggest that the GSK‐3β/NLRP3/IL‐1β pathway may be a potential therapeutic target for lupus in humans.
Synthesis of Heterocycles by Formal Cycloadditions of Isocyanides
Authors: Kruithof Art , Ruijter Eelco , Orru Romano V. A.
Published: December 2014

Synthetic methodology for the synthesis of heterocycles is of continuous and high interest with applications in materials, catalysis, and medicines. Multicomponent reactions are suitable tools to efficiently generate chemically diverse sets of heterocycles with sufficient structural complexity. Especially isocyanides have proven to be particularly versatile building blocks in these one‐pot processes. Due to their electronic structure, isocyanides are able to act sequentially or simultaneously as a nucleophile and an electrophile. Traditionally, isocyanides are therefore frequently used in multicomponent chemistry. In the recent literature, numerous reactions have been reported that involve formal cycloadditions of isocyanides with conjugated heterodienes. This Focus Review aims at mapping this reactivity and at providing insight into the relationship between the various reported reaction partners and the observed reactivity modes.
Intelligent Integral Backstepping Sliding‐mode Control Using Recurrent Neural Network For Piezo‐flexural Nanopositioning Stage
Authors: Lin Faa‐Jeng , Lee Shih‐Yang , Chou Po‐Huan
Published: December 2014

In this study, an intelligent integral backstepping sliding‐mode control (IIBSMC) system using a recurrent neural network (RNN) is proposed for the three‐dimensional motion control of a piezo‐flexural nanopositioning stage (PFNS). First, the dynamic model of the PFNS is derived. Then, an integral backstepping sliding‐mode control (IBSMC) system is proposed for the tracking of the reference contours. The steady‐state response of the control system can be improved effectively due to the addition of the integrator in the IBSMC. Moreover, to relax the requirements of the bound and discard the switching function in the IBSMC, an IIBSMC system using an RNN estimator is proposed to improve the control performance and the robustness of the PFNS. The RNN estimator is proposed to estimate the lumped uncertainty, including the system parameters and external disturbance, online. Furthermore, the online tuning law for the training of the parameters of the RNN is derived using the Lyapunov stability theorem. In addition, a robust compensator is proposed to confront the minimum reconstructed error occurring in the IIBSMC system. Finally, some experimental results for the tracking of various contours are given to demonstrate the validity of the proposed IIBSMC system. From the performance measurements of the proportional‐integral control, sliding mode control, IBSMC, and IIBSMC systems, the proposed IIBSMC system has the lowest maximum, average, and standard deviation of the position tracking errors for three‐dimensional motion control of the PFNS.
Impacts of environmental humidity on concentric eyewall structure
Authors: Ge Xuyang
Published: December 2014

The tropical cyclone (TC) secondary eyewall (SE) is an important aspect of TC intensity and structure forecast, because it largely affects the horizontal scale of destructive winds and heavy rainfall. Hence, it is important to understand the possible factors that influence the structure and size of SE. Idealized simulations suggest that the environmental humidity is one of the key factors. It is favorable for TC to establish a SE in a moist environment. Furthermore, the SE is likely to be located at a larger radius, thereby leads to a wider moat area. Consequently, the structure of SE would affect TC intensity change during the eyewall replacement cycle. This study strongly motivates further researches with respect to how the environmental conditions influence the storm dynamics and thermodynamics.
Ectokinases as novel cancer markers and drug targets in cancer therapy
Authors: Yalak Garif , Vogel Viola
Published: December 2014

While small‐molecule kinase inhibitors became the most prominent anticancer drugs, novel combinatorial strategies need to be developed as the fight against cancer is not yet won. We review emerging literature showing that the release of several ectokinases is significantly upregulated in body fluids from cancer patients and that they leave behind their unique signatures on extracellular matrix (ECM) proteins. Our analysis of proteomic data reveals that fibronectin is heavily phosphorylated in cancer tissues particularly within its growth factor binding sites and on domains that regulate fibrillogenesis. We are thus making the case that cancer is not only a disease of cells but also of the ECM. Targeting extracellular kinases or the extracellular signatures they leave behind might thus create novel opportunities in cancer diagnosis as well as new avenues to interfere with cancer progression and malignancy.
Recognize the valuable role of athletic trainers
Authors: Neal Timothy , Quandt Eric , Thornton James , Anderson Jeffrey
Published: December 2014

The competitive nature of intercollegiate athletics is an alluring feature for fans, alumni and the media. This places great pressure for success on athletics departments, coaches and student‐athletes. This pressure may even extend into the medical care and well‐being of student‐athletes. The competitive nature of coaches and student‐athletes may color their reactions to medical decisions made by sports medicine staff members and team physicians, who base their decisions on the long‐term well‐being of the student‐athletes.
How the news surrounding Ebola can impact children in America
Authors: Fritz Gregory K.
Published: December 2014

When I was in second grade and living in Racine, Wisconsin, there was a rabies outbreak in the greater Chicago area that received extensive media coverage. Parents kept children indoors because of a perceived risk of marauding mad dogs, and stories about the horrors of having to undergo the treatment shots were widely discussed. Even though I loved dogs, I was petrified of being bitten by a rabid animal. A recurring image from the front page of the newspaper (which I still vividly recall) of a wild‐eyed dog foaming at the mouth and fiercely biting the bars of its quarantine cage made it difficult to fall asleep many nights that fall. I've wondered whether that childhood experience of fearing a deadly illness I didn't understand influenced my decision to go into medicine. I am certain, however, that a widespread concern about a scary disease, whether it's rabies or Ebola, can affect children and adolescents in lasting ways.
The Power of Advertising — Teach Your Children to Be Informed Consumers: A Guide for Parents
Authors: Knopf Alison
Published: December 2014

As legalized recreational marijuana use becomes more widespread, against the advice of medical groups, adolescents are going to be faced more and more with mixed messages. Proponents of legalization say this doesn't need to be a dilemma for parents, because all legalized marijuana is legal only for ages 21 and over.
“Optimized” delivery of intracoronary supersaturated oxygen in acute anterior myocardial infarction: A feasibility and safety study
Authors: Hanson Ivan D. , David Shukri W. , Dixon Simon R. , Metzger D. Christopher , Généreux Philippe , Maehara Akiko , Xu Ke , Stone Gregg W.
Published: December 2014

Objectives

We sought to evaluate the feasibility and safety of catheter‐based supersaturated oxygen (SSO2) delivery via the left main coronary artery (LMCA) following primary percutaneous coronary intervention (PCI). Background: In the multicenter, randomized AMIHOT‐II trial, SSO2 delivered into the proximal or mid left anterior descending (LAD) artery via an indwelling intracoronary infusion catheter in patients with acute anterior ST‐segment elevation myocardial infarction (STEMI) following primary PCI significantly reduced infarct size but resulted in a numerically higher incidence of safety events. Methods: Patients with acute anterior STEMI presenting within 6 hr of symptom onset were enrolled at three centers. Following successful LAD stenting, SSO2 was infused into the LMCA via a diagnostic catheter for 60 min. The primary safety endpoint was the 30‐day rate of target vessel failure (composite of death, reinfarction, or target vessel revascularization). Cardiac magnetic resonance imaging (cMRI) was performed at 3–5 and 30 days to assess infarct size. Results: Twenty patients with acute anterior STEMI were enrolled. The infarct lesion was located in the proximal LAD in 7 cases (35%) and the mid LAD in 13 cases (65%). Following primary PCI, SSO2 was delivered successfully in all cases. Target vessel failure within 30 days occurred in 1 patient (5%). Median [interquartile range] infarct size was 13.7% [5.4–20.6%] at 3–5 days and 9.6% [2.1–14.5%] at 30 days. Conclusions: Following primary PCI in acute anterior STEMI, infusion of SSO2 via the LMCA is feasible, and is associated with a favorable early safety and efficacy profile. © 2015 Wiley Periodicals, Inc.
Two‐in‐one aortic valve sizing and valvuloplasty conductance balloon catheter
Authors: Svendsen Mark C. , Sinha Anjan K. , Berwick Zachary C. , Combs William , Teague Shawn D. , Lefevre Thierry , Babaliaros Vasilis , Kassab Ghassan
Published: December 2014

Background

Inaccurate aortic valve sizing and selection is linked to paravalvular leakage in transcatheter aortic valve replacement (TAVR). Here, a novel sizing valvuloplasty conductance balloon (SVCB) catheter is shown to be accurate, reproducible, unbiased, and provides real‐time tool for aortic valve sizing that fits within the standard valvuloplasty procedure.

Methods and Results

The SVCB catheter is a valvuloplasty device that uses real‐time electrical conductance measurements based on Ohm's Law to size the balloon opposed against the aortic valve at any given inflation pressure. Accuracy and repeatability of the SVCB catheter was performed on the bench in phantoms of known dimension and ex vivo in three domestic swine aortic annuli with comparison to computed tomography (CT) and dilator measurements. Procedural workflow and safety was demonstrated in vivo in three additional domestic swine. SVCB catheter measurements had negligible bias or error for bench accuracy considered as the gold standard (Bias: −0.11 ± 0.26 mm; Error: 1.2%), but greater disagreement in ex vivo versus dilators (Bias: −0.3 ± 1.1 mm; Error: 4.5%), and ex vivo versus CT (Bias: −1.0 ± 1.6 mm; Error: 8.7%). The dilator versus CT accuracy showed similar agreement (Bias: −0.9 ± 1.5 mm; Error: 7.3%). Repeatability was excellent on the bench (Bias: 0.02 ± 0.12 mm; Error: 0.5%) and ex vivo (Bias: −0.4 ± 0.9 mm; Error: 4.6%). In animal studies, the device fit well within the procedural workflow with no adverse events or complications.

Conclusions

Due to the clinical relevance of this accurate, repeatable, unbiased, and real‐time sizing measurement, the SVCB catheter may provide a useful tool prior to TAVR. These findings merit a future human study. © 2015 Wiley Periodicals, Inc.
A randomized study comparing the use of a pelvic lead shield during trans‐radial interventions: Threefold decrease in radiation to the operator but double exposure to the patient
Authors: Musallam Anees , Volis Ina , Dadaev Svetlana , Abergel Eitan , Soni Amit , Yalonetsky Sergey , Kerner Arthur , Roguin Ariel
Published: December 2014

Objectives

To determine the efficacy of a 0.5‐mm lead apron across the patient's abdomen in addition to standard operator protection for the reduction of scatter radiation on operator and patient radiation exposure

Background

Cardiac angiography using the radial access compared to the femoral approach is associated with reduced complication rate and improved patient comfort but has significantly increased radiation dose. Improvements in radiation protection are needed

Methods

We randomly assigned 332 patients undergoing coronary angiography to a group with pelvic lead shielding and a group with standard protection. In each procedure, eight digital dosimeters were used to measure operator radiation dose [under the lead apron, outside the thyroid shield, and at the left side of the head], patient dose at the level of the umbilicus [above and beneath the lead apron], and two on the acrylic shielding and one on the image receptor to measure scattered radiation

Results

Both groups were similar in BMI, procedures performed, and number of sequences. Usage of lead shielding statistically significantly reduced the radiation dose of the operator at all three sites measured: under lead apron [all in µSv]: 0.53 ± 1.4 vs. 0.17 ± 0.6, on thyroid collar 5.9 ± 7.7 vs. 2.9 ± 3.4, and left side of head 3.3 ± 3.4 vs. 2.1 ± 2.2, P < 0.001. However the radiation to the patient was doubled from 15.4 ± 24.1 to 28.9 ± 81.1, P = 0.04

Conclusions

The use of a pelvic lead shield during radial angiography reduced the operator radiation exposure at multiple measurement sites. However there was an increased exposure to the patient. This balance should be further investigated before the widespread adoption of this method. © 2015 Wiley Periodicals, Inc.
Outcomes and predictors of mortality after transcatheter aortic valve implantation: Results of the Brazilian registry
Authors: de Brito Fábio S. , Carvalho Luiz A. , Sarmento‐Leite Rogério , Mangione José A. , Lemos Pedro , Siciliano Alexandre , Caramori Paulo , São Thiago Luiz , Grube Eberhard , Abizaid Alexandre ,   on behalf of the Brazilian TAVI Registry investigators
Published: December 2014

Objective

The study sought to evaluate outcomes and predictors of mortality after transcatheter aortic valve implantation (TAVI).

Background

TAVI registries can reliably address outcomes and issues that adversely affect results in real‐life.

Methods

All endpoints and complications were analyzed according to Valve Academic Research Consortium‐2 criteria.

Results

Between January 2008 and January 2013, 418 patients underwent TAVI in 18 centers and were included in the Brazilian registry. The transfemoral approach was used in 96.2% of the procedures. The CoreValve and Sapien XT prosthesis were used in 360 (86.1%) and 58 (13.9%) cases, respectively. All‐cause mortality at 30 days and 1 year were 9.1 and 21.5%. Chronic obstructive pulmonary disease (COPD) (HR: 3.50), acute kidney injury (AKI) (HR: 3.07), stroke (HR: 2.71) and moderate/severe paravalvular regurgitation (PVR) (HR: 2.76) emerged as independent predictors of overall mortality. COPD (OR: 3.00), major vascular complications (OR: 7.99) and device malpositioning (OR: 6.97) were predictors of early (≤30 days) mortality, while COPD (HR: 2.68), NYHA class III/IV (HR: 3.04), stroke (HR: 4.15), AKI (HR: 2.44) and moderate/severe PVR (HR: 3.20) impacted late (>30 days) mortality. The use of transesophageal echocardiogram (TEE) to monitor the procedure was found to be a protective factor against overall (HR: 0.57) and late (HR: 0.47) mortality.

Conclusion

This multicenter registry reflected a real‐life national TAVI experience. Comorbidities, periprocedural complications and moderate/severe PVR were associated with increased mortality and the use of TEE to monitor the procedure acted as a protective factor. © 2014 Wiley Periodicals, Inc.
Transcatheter aortic valve implantation using the left transcarotid approach in patients with previous ipsilateral carotid endarterectomy
Authors: Pozzi Matteo , Grinberg Daniel , Obadia Jean‐François , Saroul Christine , Green Lisa , Dementhon Julie , Pizzighini Sarah , Rioufol Gilles , Finet Gerard , Modine Thomas
Published: December 2014

Objectives

To assess the feasibility and safety of transcatheter aortic valve implantation (TAVI) through a left transcarotid approach in patients previously operated on for ipsilateral carotid endarterectomy (CEA).

Background

The healthcare impact of extracranial carotid artery disease is essential as stroke is the third‐leading cause of death in industrialized nations and CEA is often present in the history of patients awaiting TAVI.

Methods

The primary endpoint was to evaluate 30‐day mortality and freedom from major TAVI‐related complications in an observational analysis.

Results

From December 2011 to February 2014, we performed 9 TAVI. The mean age was 84.6 years. The procedure was performed without any technical complication or vascular injury in every patient. There was neither intraoperative mortality nor intraoperative major complications. One (11.1%) patient experienced spatial‐temporal disorientation but cerebral computed tomography did not show any sign of stroke. Two (22.2%) patients needed the implantation of a pacemaker due to third‐degree atrioventricular block appearance. Three (33.3%) patients were transfused with packed red blood cells and 1 (11.1%) patient developed a groin hematoma. Only 1 (11.1%) patient showed a residual paravalvular regurgitation ≥ 2. At 30‐day follow‐up there was neither mortality nor other TAVI‐related complications and echocardiography parameters remained stable.

Conclusions

TAVI through a left transcarotid approach in patients previously operated on for ipsilateral CEA is feasible and safe. The presence of a previous ipsilateral CEA represents no more a limitation to the utilization of this promising access route. At short‐term follow‐up, mortality and major complications rates are low. © 2014 Wiley Periodicals, Inc.
Multimodality imaging of attenuated plaque using grayscale and virtual histology intravascular ultrasound and optical coherent tomography
Authors: Kang Soo‐Jin , Ahn Jung‐Min , Han Seungbong , Park Duk‐Woo , Lee Seung‐Whan , Kim Young‐Hak , Lee Cheol Whan , Park Seong‐Wook , Mintz Gary S. , Park Seung‐Jung
Published: December 2014

Background

Although attenuated plaque is a marker for plaque vulnerability, the quantification and its implication have not been known.

Methods

Multimodality pre‐procedural imaging using grayscale intravascular ultrasound (IVUS), virtual histology‐IVUS (VH‐IVUS), and optical coherence tomography (OCT) were performed in 115 coronary lesions with diameter stenosis (DS) >30% and plaque burden ≥50% and compared the diagnostic accuracies for detecting thin‐cap fibroatheromas (TCFA).

Results

A maximal arc of attenuation (40 MHz IVUS) ≥29.0° was the cutoff for predicting VH‐TCFA (sensitivity 74%, specificity 66%); and OCT‐TCFA (sensitivity 89%, specificity 64%), while a maximal arc attenuation ≥29.0° (20MHz IVUS) showed a poor sensitivity for predicting TCFA. Compared to the lesions with an arc of attenuation <30° as a rough cutoff value, the lesions with a maximum arc of attenuation ≥30° (40 MHz) were associated with more severe (smaller angiographic minimum lumen diameter and greater DS, smaller IVUS‐MLA and a larger plaque burden) and had more unstable lesion characteristics: (1) larger remodeling index and more plaque ruptures (grayscale IVUS); (2) greater %necrotic core and more VH‐TCFAs (VH‐IVUS); and (3) more lipid, macrophages, cholesterol crystals, and microchannels; thinner fibrous caps; and more OCT‐TCFAs, OCT‐detected plaque ruptures, and red and white thrombi (OCT). Among 58 patients treated with stent implantation, postintervention peak CK‐MB was higher in patients with the maximal attenuation ≥30° compared to those without (median 2.7 ng/ml [IQR 0.9–18.7 ng/ml] vs. median 0.9 ng/ml [IQR 0.7–2.1 ng/ml], P = 0.012).

Conclusion

Attenuated plaque with a maximal attenuation ≥30° vs. <30° (40 MHz, but not 20 MHz IVUS) were more likely to be associated with unstable lesion morphology that may contribute to the immediate poststenting CK‐MB elevation. © 2016 Wiley Periodicals, Inc.
Inherent Electrochemistry of Layered Post‐Transition Metal Halides: The Unexpected Effect of Potential Cycling of PbI2
Authors: Chua Chun Kiang , Sofer Zdeněk , Lim Chee Shan , Pumera Martin
Published: December 2014

The development of two‐dimensional nanomaterials has expedited the growth of advanced technological applications. PbI2 is a layered inorganic solid with important and unique properties suitable for applications in the detection of electromagnetic radiation. While the optical and electrical properties of layered PbI2 have been generally established, its electrochemistry has remained largely unexplored. In this work, we examine the inherent electrochemistry of PbI2 in relation to its morphological and structural properties. A direct comparison between commercially available and solution‐grown PbI2 showed high similarity in properties based on characterizations by X‐ray photoelectron spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy. The respective layered PbI2 materials also exhibited similar inherent electrochemistry. Electrochemical potential cycling of PbI2 in phosphate buffer resulted in the dissolution of iodide ions from PbI2 to form complex lead‐phosphate‐chloride with the oxygen groups of the phosphate ions while retaining the hexagonal structure. In the case of KCl solution, the formation of PbO2 was observed.
Hydrolysis of Hydrophobic Esters in a Bicontinuous Microemulsion Catalysed by Lipase B from Candida antarctica
Authors: Steudle Anne K. , Subinya Mireia , Nestl Bettina M. , Stubenrauch Cosima
Published: December 2014

Selective enzyme‐catalysed biotransformations offer great potential in organic chemistry. However, special requirements are needed to achieve optimum enzyme activity and stability. A bicontinuous microemulsion is proposed as reaction medium because of its large connected interface between oil and water domains at which a lipase can adsorb and convert substrates in the oil phase of the microemulsion. Herein, a microemulsion consisting of buffer–n‐octane–nonionic surfactant CiEj was used to investigate the key factors that determine hydrolyses of p‐nitrophenyl esters catalysed by the lipase B from Candida antarctica (CalB). The highest CalB activity was found around 44 °C in the absence of NaCl and substrates with larger alkyl chains were better hydrolysed than their short‐chained homologues. The CalB activity was determined using two different co‐surfactants, namely the phospholipid 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) and the sugar surfactant decyl β‐D‐glucopyranoside (β‐C10G1). The results show the CalB activity as linear function of both enzyme and substrate concentration with an enhanced activity when the sugar surfactant is used as co‐surfactant.
Influence of Synthesis pH and Oxidative Strength of the Catalyzing Acid on the Morphology and Chemical Structure of Hydrothermal Carbon
Authors: Reiche Sylvia , Kowalew Natalia , Schlögl Robert
Published: December 2014

A specific control of the morphology and chemical structure of hydrothermal carbon (HTC) is of crucial importance for its application, both in catalyst supports or electrochemical devices. Here we show how the morphology, that is, particles size and homogeneity, and the distribution of functional groups can be controlled by the control of the synthesis pH of the hydrothermal carbonization. A complementary analysis of liquid byproducts by HPLC provides useful information on the nature of the polymeric species produced during the poly‐condensation in the hydrothermal process and reveals the potential implementation of the process into the biorefinery concept. The acidic byproducts levulinic acid and formic acid determine the hydrothermal carbonization autocatalytically by additional supply of protons to the reaction medium. Thus, for a starting pH>3, only minor structural differences can be detected for HTC. The use of oxidizing acids favors higher yields of HTC and improves carbonization towards higher condensed carbon domains. Scaling up the process in a stirred 2 L batch reactor favors carbonization leading to higher condensed carbonaceous products. The relative trends of pH variation are maintained.
Photoelectron Circular Dichroism of Bicyclic Ketones from Multiphoton Ionization with Femtosecond Laser Pulses
Authors: Lux Christian , Wollenhaupt Matthias , Sarpe Cristian , Baumert Thomas
Published: December 2014

The front cover artwork is provided by Prof. Thomas Baumert and co‐workers (Institut für Physik und CINSaT Universität Kassel) and Prof. Matthias Wollenhaupt (Carl von Ossietzky Universität Oldenburg). The image shows circular dichroism in the 10 % regime from randomly oriented (S)‐(−)‐camphor molecules in the gas phase observed on the 3D momentum distribution of ejected photoelectrons after three‐photon ionization with a table‐top laser set‐up. Read the full text of the article at 10.1002/cphc.201402643.
Selective Hydrogenation of Lactic Acid to 1,2‐Propanediol over Highly Active Ruthenium–Molybdenum Oxide Catalysts
Authors: Takeda Yasuyuki , Shoji Tomohiro , Watanabe Hideo , Tamura Masazumi , Nakagawa Yoshinao , Okumura Kazu , Tomishige Keiichi
Published: December 2014

Modification of Ru/C with a small amount of MoOx (RuMoOx/C) enhanced the catalytic activity in the hydrogenation of L‐lactic acid to form 1,2‐propanediol and maintained high selectivity. The turnover frequency based on the amount of Ru over the optimized RuMoOx/C catalyst (Mo/Ru molar ratio=1:16) was 114 h−1 at 393 K, which was about 4 times higher than that over Ru/C. The same effect of MoOx was obtained over RuMoOx/SiO2, although RuMoOx/SiO2 showed slightly lower activity than that of RuMoOx/C. RuMoOx/C achieved a high yield of 95 % in 18 h at 393 K and was applicable to various carboxylic acids to provide the corresponding alcohols in high yields. Modification with MoOx also brought about suppression of racemization and (S)‐1,2‐propanediol was obtained in high enantiomeric excess at 353 K. Based on kinetic analysis and characterization data, such as XRD, TEM, CO adsorption by a volumetric method, FTIR spectroscopy, and X‐ray absorption spectroscopy, for RuMoOx/C and RuMoOx/SiO2, the catalyst structure and reaction mechanism are proposed.
A meta‐epidemiological study to examine the association between bias and treatment effects in neonatal trials
Authors: Bialy Liza , Vandermeer Ben , Lacaze‐Masmonteil Thierry , Dryden Donna M. , Hartling Lisa
Published: December 2014

Background:

Randomized controlled trials are considered the gold standard for evidence on therapeutic interventions; however, they are susceptible to bias. The objectives of this observational study were to describe the methodological quality of neonatal randomized controlled trials and quantify the bias related to specific methodological and study‐level characteristics.

Methods:

Twenty‐five systematic reviews yielding 208 neonatal trials were included. Two independent reviewers assessed risk of bias (RoB) on seven domains consisting of nine items. For each domain, meta‐analyses with at least one high/unclear and one low risk study were included in the analysis. For the primary outcome within each meta‐analysis a ratio of odds ratios with a 95% confidence interval was generated. The ratio of odds ratios for each meta‐analysis were combined using meta‐analytic techniques with inverse‐variance weighting and a random effects model to obtain a summary ratio of odds ratio.

Results:

None of the studies had an overall low RoB. Most studies had a low RoB for the domain of incomplete outcome data (89%), while 63%, 55% and 46% of trials had low RoB for sequence generation, other sources of bias, and blinding of outcome assessors, respectively. For all other domains (allocation concealment, blinding of parents and investigators and selective outcome reporting), the majority of trials were assessed as unclear. Selective outcome reporting was rated as unclear RoB for 55% and high for 42% of studies. The only domain that showed a statistically significant association with the treatment effect was selective outcome reporting: trials at unclear/high risk of bias for this domain significantly overestimated the treatment effects compared with those assessed at low risk of bias (ROR = 1.87, 95% confidence interval: 1.26–2.78).

Conclusions:

This observational study of a sample of neonatal trials showed that most were at high risk of bias, indicating that there is room for improvement in the design, conduct and reporting of neonatal trials to ensure valid results for the most clinically important outcomes. We did not find an association between most risk of bias domains and effect estimates; however, we found that randomized controlled trials at high risk for selective outcome reporting were associated with overestimates of treatment benefits. These results need to be confirmed in larger samples.