bluuebunny/crossref_metadata_2025 huggingface dataset:
Invisible Hyperbolic Metamaterial Nanotube at Visible Frequency
Authors: Kim Kyoung-Ho , No You-Shin , Chang Sehwan , Choi Jae-Hyuck , Park Hong-Gyu
Published: November 2015

Subwavelength-scale metal and dielectric nanostructures have served as important building blocks for electromagnetic metamaterials, providing unprecedented opportunities for manipulating the optical response of the matter. Recently, hyperbolic metamaterials have been drawing particular interest because of their unusual optical properties and functionalities, such as negative refraction and hyperlensing of light. Here, as a promising application of a hyperbolic metamaterial at visible frequency, we propose an invisible nanotube that consists of metal and dielectric alternating thin layers. The theoretical study of the light scattering of the layered nanotube reveals that almost-zero scattering can be achieved at a specific wavelength when the transverse-electric- or transverse-magnetic-polarized light is incident to the nanotube. In addition, the layered nanotube can be described as a radial-anisotropic hyperbolic metamaterial nanotube. The low scattering occurs when the effective permittivity of the hyperbolic nanotube in the angular direction is near zero and thus the invisibility of the layered nanotube can be efficiently obtained by analyzing the equivalent hyperbolic nanotube. Our new method to design and tune an invisible nanostructure represents a significant step toward the practical implementation of unique nanophotonic devices such as invisible photodetectors and low-scattering near-field optical microscopes.
Decadal trends of the upper ocean salinity in the tropical Indo-Pacific since mid-1990s
Authors: Du Yan , Zhang Yuhong , Feng Ming , Wang Tianyu , Zhang Ningning , Wijffels Susan
Published: November 2015

A contrasting trend pattern of sea surface salinity (SSS) between the western tropical Pacific (WTP) and the southeastern tropical Indian Ocean (SETIO) is observed during 2004–2013, with significant salinity increase in the WTP and freshening in the SETIO. In this study, we show that increased precipitation around the Maritime Continent (MC), decreased precipitation in the western-central tropical Pacific and ocean advection processes contribute to the salinity trends in the region. From a longer historical record, these salinity trends started in the mid-1990s, a few years before the Global Warming Hiatus from 1998 to present. The salinity trends are associated a strengthening trend of the Walker Circulation over the tropical Indo-Pacific, which have reversed the long-term salinity changes in the tropical Indo-Pacific as a consequence of global warming. Understanding decadal variations of SSS in the tropical Indo-Pacific will better inform on how the tropical hydrological cycle will be affected by the natural variability and a warming climate.
Sensitive electrochemical nonenzymatic glucose sensing based on anodized CuO nanowires on three-dimensional porous copper foam
Authors: Li Zhenzhen , Chen Yan , Xin Yanmei , Zhang Zhonghai
Published: November 2015

In this work, we proposed to utilize three-dimensional porous copper foam (CF) as conductive substrate and precursor of in-situ growth CuO nanowires (NWs) for fabricating electrochemical nonenzymatic glucose sensors. The CF supplied high surface area due to its unique three-dimensional porous foam structure and thus resulted in high sensitivity for glucose detection. The CuO NWs/CF based nonenzymatic sensors presented reliable selectivity, good repeatability, reproducibility and stability. In addition, the CuO NWs/CF based nonenzymatic sensors have been employed for practical applications and the glucose concentration in human serum was measured to be 4.96 ± 0.06 mM, agreed well with the value measured from the commercial available glucose sensor in hospital and the glucose concentration in saliva was also estimated to be 0.91 ± 0.04 mM, which indicated that the CuO NWs/CF owned the possibility for noninvasive glucose detection. The rational design of CuO NWs/CF provided an efficient strategy for fabricating of electrochemical nonenzymatic biosensors.
Evidence for a surface gold hydride on a nanostructured gold catalyst
Authors: Silverwood I. P. , Rogers S. M. , Callear S. K. , Parker S. F. , Catlow C. R. A.
Published: November 2015

Inelastic neutron scattering and isotopic infrared spectroscopy shows formation of surface Au–H, an important intermediate in catalytic mechanisms.
Enzyme encapsulation in zeolitic imidazolate frameworks: a comparison between controlled co-precipitation and biomimetic mineralisation
Authors: Liang Kang , Coghlan Campbell J. , Bell Stephen G. , Doonan Christian , Falcaro Paolo
Published: November 2015

Recent studies have demonstrated that metal–organic frameworks can be employed as protective coatings for enzymes.
Evolution and characterization of a benzylguanine-binding RNA aptamer
Authors: Xu J. , Carrocci T. J. , Hoskins A. A.
Published: November 2015

We report the evolution and characterization of a benzylguanine-binding RNA aptamer for fluorophore labeling or RNA purification.
Acid/base controllable complexation of a triptycene-derived macrotricyclic host and protonated 4,4′-bipyridinium/pyridinium salts
Authors: Han Ying , Meng Zheng , Chen Chuan-Feng
Published: November 2015

A new acid/base controllable host–guest system based on a triptycene-derived macrotricyclic host and protonated 4,4′-bipyridinium/pyridinium salts was developed.
Enhanced field-emission of silver nanoparticle–graphene oxide decorated ZnO nanowire arrays
Authors: Wang Guojing , Li Zhengcao , Li Mingyang , Liao Jiecui , Chen Chienhua , Lv Shasha , Shi Chuanqing
Published: November 2015

A new method to improve the field emission properties of ZnO by graphene oxide and silver nanocomposite modification.
Stability of two-dimensional PN monolayer sheets and their electronic properties
Authors: Ma ShuangYing , He Chaoyu , Sun L. Z. , Lin Haiping , Li Youyong , Zhang K. W.
Published: November 2015

Three two-dimensional phosphorus nitride (PN) monolayer sheets (named as α-, β-, and γ-PN, respectively) with fantastic structures and properties are predicted based on first-principles calculations.
Metallic ruthenium nanoparticles for hydrogenation of supercritical carbon dioxide
Authors: Umegaki T. , Enomoto Y. , Kojima Y.
Published: November 2015

Metallic ruthenium nanoparticles prepared in a methyl alcohol solution under solvothermal conditions showed high activity for hydrogenation of supercritical carbon dioxide to formic acid.
Ionic liquids as solvents for PPTA oligomers
Authors: Dewilde Sven , Dehaen Wim , Binnemans Koen
Published: November 2015

Ionic liquids with coordinating anions can break up the hydrogen bond network of PPTA oligomers. Phosphonium ionic liquids were found to be the strongest solvents enabling them to be possible alternatives for the synthesis of PPTA.
Laser ablation molecular isotopic spectrometry (LAMIS): current state of the art
Authors: Bol'shakov Alexander A. , Mao Xianglei , González Jhanis J. , Russo Richard E.
Published: November 2015

Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is a direct and rapid technique that measures optical emission in laser-induced plasmas for isotopic analysis.
All-solution processed transparent organic light emitting diodes
Authors: Zhang Min , Höfle Stefan , Czolk Jens , Mertens Adrian , Colsmann Alexander
Published: November 2015

Transparent organic light emitting diodes with polymer electrodes and low onset voltages are fabricated all from solution.
Cationic and reactive primary amine-stabilised nanoparticles via RAFT aqueous dispersion polymerisation
Authors: Williams M. , Penfold N. J. W. , Armes S. P.
Published: November 2015

Synthesis of cationic reactive primary amine-functionalized diblock copolymer nano-objects via polymerisation-induced self-assembly (PISA) using a RAFT aqueous dispersion polymerisation formulation is reported.
Pt–Ru/Al2O3–C nanocomposites as direct methanol fuel cell catalysts for electrooxidation of methanol in acidic medium
Authors: Das Suparna , Kundu Patit P.
Published: November 2015

We have employed different ratios of Al2O3 and Vulcan carbon as supporting matrices for a Pt–Ru catalyst for direct methanol fuel cell catalysts.
Direct electrospinning construction of nanocables with electrical conductive-magnetic core and insulative-photoluminescent sheath
Authors: Han Lei , Ma Qianli , Dong Xiangting
Published: November 2015

A new nanostructure of luminescent-electrical-magnetic trifunctional nanocables has been successfully fabricated by specially designed coaxial spinnerets electrospinning technology.
Flux growth of patterned LiCoO2 crystal arrays directly on a Pt substrate in molten LiNO3
Authors: Yoda T. , Zettsu N. , Onodera H. , Mizuno Y. , Kondo H. , Teshima K.
Published: November 2015

We demonstrate a new way to prepare hollow-structured LiCoO2 crystals directly on a Pt substrate for the first time through a combination of semi-additive electrodeposition of a Co core and subsequent flux growth in molten LiNO3.
A novel epoxy-functionalized hyperbranched polysiloxane (HPSi) endowing methyl phenyl silicone resin (Si603)/epoxy systems with enhanced compatibility and fire retardancy performance
Authors: Jia Pei , Liu Hanchao , Wang Youchuan , Cai Xufu
Published: November 2015

A novel hyperbranched polysiloxane (HPSi) with a great amount of epoxy groups was synthesized as a compatibilizer of epoxy resin (EP)/methyl phenyl silicone resin (Si603) blends.
Facile synthesis of high lithium ion conductive cubic phase lithium garnets for electrochemical energy storage devices
Authors: Dhivya L. , Karthik K. , Ramakumar S. , Murugan Ramaswamy
Published: November 2015

A facile combustion method was developed for the rapid synthesis of high conductive cubic phase Al-LLZ solid electrolyte with uniform particle sizes at the nanometer level for the fabrication of rechargeable all-solid-state Li and Li-air batteries.
Effect of 4,4′-stilbenedicarboxylic acid-intercalated layered double hydroxides on UV aging resistance of bitumen
Authors: Peng Chao , Jiang Guosheng , Lu Chunhua , Xu Fang , Yu Jianying , Dai Jing
Published: November 2015

UV aging is the main cause of the deterioration of bitumen pavement.
Influence of the heteroatom on the optoelectronic properties and transistor performance of soluble thiophene-, selenophene- and tellurophene–vinylene copolymers
Authors: Al-Hashimi Mohammed , Han Yang , Smith Jeremy , Bazzi Hassan S. , Alqaradawi Siham Yousuf A. , Watkins Scott E. , Anthopoulos Thomas D. , Heeney Martin
Published: November 2015

We report the first soluble poly(3-dodecyl tellurophenylenevinylene) and compare its properties to the analogous thiophene and selenophene containing polymers.
Highly parallel acoustic assembly of microparticles into well-ordered colloidal crystallites
Authors: Owens Crystal E. , Shields C. Wyatt , Cruz Daniela F. , Charbonneau Patrick , López Gabriel P.
Published: November 2015

We present a method to assemble microparticles into well-ordered crystallites using acoustic standing waves and quantitatively simulate the formation of the emergent structures.
Alkali metals incorporated ordered mesoporous tantalum oxide with enhanced photocatalytic activity for water splitting
Authors: Grewe Tobias , Tüysüz Harun
Published: November 2015

We present a soft-templating synthesis of amorphous ordered mesoporous tantalates with incorporated alkali earth metals for photocatalytic water splitting.
Porous NiCo2O4nanotubes as a noble-metal-free effective bifunctional catalyst for rechargeable Li–O2batteries
Authors: Li Laiyang , Shen Laifa , Nie Ping , Pang Gang , Wang Jie , Li Hongsen , Dong Shengyang , Zhang Xiaogang
Published: November 2015

Porous NiCo2O4nanotubes as an effective bifunctional catalyst for use in rechargeable Li–O2batteries with an excellent cycling stability.
Facile growth of porous Fe2V4O13 films for photoelectrochemical water oxidation
Authors: Tang Ding , Rettie Alexander J. E. , Mabayoje Oluwaniyi , Wygant Bryan R. , Lai Yanqing , Liu Yexiang , Mullins C. Buddie
Published: November 2015

Porous n-type Fe2V4O13 films were prepared by a simplified successive ion layer adsorption method and the photogenerated holes in the films can be efficiently utilized to oxidize water to oxygen.
A versatile pH-responsive platform for intracellular protein delivery using calcium phosphate nanoparticles
Authors: Zeng Bingru , Shi Hongdong , Liu Yangzhong
Published: November 2015

A highly biocompatible nanoplatform for the intracellular delivery of different proteins, exhibiting pH-responsive release and efficient endosomal escape.
An acid-free microwave approach to prepare highly luminescent boron-doped graphene quantum dots for cell imaging
Authors: Hai Xin , Mao Quan-Xing , Wang Wen-Jing , Wang Xiao-Feng , Chen Xu-Wei , Wang Jian-Hua
Published: November 2015

Highly luminescent graphene quantum dots (GQDs) are obtained by restoring the defects of GQDs via incorporation of B atoms into the graphene framework, which exhibits great potential in bio-imaging.
The DNA strand assisted conductive filament mechanism for improved resistive switching memory
Authors: Sun Bai , Wei Lujun , Li Hongwei , Jia Xiangjiang , Wu Jianhong , Chen Peng
Published: November 2015

The DNA strand assisted conductive filament mechanism is suggested to explain the resistive switching behaviors of the Au/CuO-DNA-Al/Au/Si device.
Pharyngo-Laryngo-Palatal Myoclonus: A Case Report and Assessment Tutorial for Clinicians
Authors: Zenga Joseph , Harmon Archie B. , Ogden M. Allison
Published: November 2015

Although palatal myoclonus has been extensively described (Deuschl, Mischke, Schenck, Schulte-Mönting, & Lücking, 1990), little is known about pharyngo-laryngo-palatal myoclonus (PLPM), a complex and rare subset of head and neck myoclonic disease. To date, there have been only 5 cases of PLPM reported (Drysdale, Ansell, & Adeley, 1993; Gupta, Samant, & Katiyar, 1972; Ito, Kimura, & Shibasaki, 1993; Juby, Shandro, & Emery, 2014; Toland, Porubsky, Coker, & Adams, 1984), and no review of the diagnosis and management of this disease has been performed. Early identification of the etiology of PLPM is critical and can aid in appropriate management, referrals, and subsequent treatment. This article presents a case of PLPM along with a review of the literature relevant to PLPM including key elements of diagnosis and treatment.
Balancing the Art and Science of the Singing Voice
Authors: Risser Rebecca
Published: November 2015

Voice therapy for elite singers developed alongside the emergence of performing arts medicine in the 1980s. By this time the field of clinical speech pathology had already established close working relationships with otolaryngologists and voice-related clinical research studies were being conducted to define treatment methods and their outcomes. In the intervening years, the art of delivering various therapy techniques, coupled with the science of vocal fold wound healing, have provided speech-language pathologists who specialize in voice a new foundation on which voice therapy is predicated and has allowed clinicians and their elite voice patients to expect epithelial vocal fold changes as a result of behavioral intervention.
Voice of Reimbursement: Medicare Coverage for Vocal Disorders
Authors: Satterfield Lisa
Published: November 2015

Speech-language pathologists (SLPs) who treat patients with vocal disorders find they are the exception —rather than the rule—when it comes to Medicare policy. This article addresses statute, regulations, and policies related to acoustical assessments, endoscopy, electronic speech aids, and tracheo-esophageal prostheses (TEPs). Acoustical assessments have limited recognition in the Medicare program and are only reimbursed in certain states, despite advocacy efforts by the American Speech-Language-Hearing Associaiton and members of the State Medicare Administrative Contractor (SMAC) Network. For endoscopy evaluations, confusion is still prevalent related to the level of physician supervision required, primarily due to the changing policies in 2011. Electronic speech aids are a benefit that is often forgotten, though the national policy allows relatively broad coverage. Finally, TEPs are the subject of SLPs, patients, manufacturers, and Congressional attention due to their limited available secondary to poor reimbursement rates and a 2010 enforcement of distribution policy. Clarification regarding the provision of traditional Medicare services (not Medicare Advantage or supplemental plans managed by private companies) and statute is discussed.
Effective interference level‐based packet transmission for multiple‐input multiple‐output systems with hybrid automatic repeat request
Authors: Whang Younghoon , Park Sangjoon , Liu Huaping
Published: November 2015

A packet transmission strategy for multiple‐input multiple‐output systems with interference cancellation detection and hybrid automatic repeat request (HARQ) processes is proposed. The error probability and throughput of such a system depend on the choice of the set of packets to be transmitted in each packet transmission time interval, but there are no existing implementable strategies to optimise such choice of packets. In this study, the authors first define a concept of the effective interference level (EIL) and establish the relationship between the EIL and the effective signal‐to‐interference‐plus‐noise ratio. Then they show that choosing the set of packets that minimises the EIL successively from the lowest to the highest HARQ round leads to a lower packet error and higher system throughput than conventional HARQ, which is verified by simulation. Also, the proposed EIL‐based scheme uses only the acknowledgement feedback messages like a conventional HARQ scheme, because the number of HARQ rounds of each packet is the only required information to calculate the EIL. Simulation results show that the proposed scheme outperforms the conventional scheme in terms of throughput with the signal‐to‐noise ratio gain of about 4.2 dB at maximum.
Perspective: Watching low-frequency vibrations of water in biomolecular recognition by THz spectroscopy
Authors: Xu Yao , Havenith Martina
Published: November 2015

Terahertz (THz) spectroscopy has turned out to be a powerful tool which is able to shed new light on the role of water in biomolecular processes. The low frequency spectrum of the solvated biomolecule in combination with MD simulations provides deep insights into the collective hydrogen bond dynamics on the sub-ps time scale. The absorption spectrum between 1 THz and 10 THz of solvated biomolecules is sensitive to changes in the fast fluctuations of the water network. Systematic studies on mutants of antifreeze proteins indicate a direct correlation between biological activity and a retardation of the (sub)-ps hydration dynamics at the protein binding site, i.e., a “hydration funnel.” Kinetic THz absorption studies probe the temporal changes of THz absorption during a biological process, and give access to the kinetics of the coupled protein-hydration dynamics. When combined with simulations, the observed results can be explained in terms of a two-tier model involving a local binding and a long range influence on the hydration bond dynamics of the water around the binding site that highlights the significance of the changes in the hydration dynamics at recognition site for biomolecular recognition. Water is shown to assist molecular recognition processes.
Charge-carrier dynamics in benzoporphyrin films investigated by time-resolved terahertz spectroscopy
Authors: Ohta Kaoru , Hiraoka Sho , Tamura Yuto , Yamada Hiroko , Tominaga Keisuke
Published: November 2015

We investigated charge-carrier dynamics in benzoporphyrin (BP) and BP-based bulk heterojunction (BHJ) films with optical pump-broadband terahertz (THz) probe spectroscopy. In both samples, we observed instantaneous appearance of transient THz signals, which are attributed to mobile charge carriers that are much lower in transition energy than excitons. These carriers recombine and/or trap at defect sites within a few ps. In the BP-based BHJ films, the decay dynamics of transient THz signals was faster relative to that in the BP films. In contrast to the BP films, approximately 10% of the transient signal does not decay within 35 ps, indicating survival of free charge carriers.
Forced wetting and hydrodynamic assist
Authors: Blake Terence D. , Fernandez-Toledano Juan-Carlos , Doyen Guillaume , De Coninck Joël
Published: November 2015

Wetting is a prerequisite for coating a uniform layer of liquid onto a solid. Wetting failure and air entrainment set the ultimate limit to coating speed. It is well known in the coating art that this limit can be postponed by manipulating the coating flow to generate what has been termed “hydrodynamic assist,” but the underlying mechanism is unclear. Experiments have shown that the conditions that postpone air entrainment also reduce the apparent dynamic contact angle, suggesting a direct link, but how the flow might affect the contact angle remains to be established. Here, we use molecular dynamics to compare the outcome of steady forced wetting with previous results for the spontaneous spreading of liquid drops and apply the molecular-kinetic theory of dynamic wetting to rationalize our findings and place them on a quantitative footing. The forced wetting simulations reveal significant slip at the solid-liquid interface and details of the flow immediately adjacent to the moving contact line. Our results confirm that the local, microscopic contact angle is dependent not simply only on the velocity of wetting but also on the nature of the flow that drives it. In particular, they support an earlier suggestion that during forced wetting, an intense shear stress in the vicinity of the contact line can assist surface tension forces in promoting dynamic wetting, thus reducing the velocity-dependence of the contact angle. Hydrodynamic assist then appears as a natural consequence of wetting that emerges when the contact line is driven by a strong and highly confined flow. Our theoretical approach also provides a self-consistent model of molecular slip at the solid-liquid interface that enables its magnitude to be estimated from dynamic contact angle measurements. In addition, the model predicts how hydrodynamic assist and slip may be influenced by liquid viscosity and solid-liquid interactions.
Reliable determination of the Cu/n-Si Schottky barrier height by using in-device hot-electron spectroscopy
Authors: Parui Subir , Atxabal Ainhoa , Ribeiro Mário , Bedoya-Pinto Amilcar , Sun Xiangnan , Llopis Roger , Casanova Fèlix , Hueso Luis E.
Published: November 2015

We show the operation of a Cu/Al2O3/Cu/n-Si hot-electron transistor for the straightforward determination of a metal/semiconductor energy barrier height even at temperatures below carrier-freeze out in the semiconductor. The hot-electron spectroscopy measurements return a fairly temperature independent value for the Cu/n-Si barrier of 0.66 ± 0.04 eV at temperatures below 180 K, in substantial accordance with mainstream methods based on complex fittings of either current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Cu/n-Si hot-electron transistors exhibit an OFF current of ∼2 × 10−13 A, an ON/OFF ratio of ∼105, and an equivalent subthreshold swing of ∼96 mV/dec at low temperatures, which are suitable values for potential high frequency devices.
Construction of a magnetic bottle spectrometer and its application to pulse duration measurement of X-ray laser using a pump-probe method
Authors: Namba S. , Hasegawa N. , Kishimoto M. , Nishikino M. , Ishino M. , Kawachi T.
Published: November 2015

To characterize the temporal evolution of ultrashort X-ray pulses emitted by laser plasmas using a pump-probe method, a magnetic bottle time-of-flight electron spectrometer is constructed. The design is determined by numerical calculations of a mirror magnetic field and of the electron trajectory in a flight tube. The performance of the spectrometer is characterized by measuring the electron spectra of xenon atoms irradiated with a laser-driven plasma X-ray pulse. In addition, two-color above-threshold ionization (ATI) experiment is conducted for measurement of the X-ray laser pulse duration, in which xenon atoms are simultaneously irradiated with an X-ray laser pump and an IR laser probe. The correlation in the intensity of the sideband spectra of the 4d inner-shell photoelectrons and in the time delay of the two laser pulses yields an X-ray pulse width of 5.7 ps, in good agreement with the value obtained using an X-ray streak camera.
Effects of oxygen tension and dextran-shelled/2H,3H-decafluoropentane-cored oxygen-loaded nanodroplets on secretion of gelatinases and their inhibitors in term human placenta
Authors: Prato Mauro , Khadjavi Amina , Magnetto Chiara , Gulino Giulia Rossana , Rolfo Alessandro , Todros Tullia , Cavalli Roberta , Guiot Caterina
Published: November 2015

Matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) need to be finely modulated in physiological processes. However, oxygen tension influences MMP/TIMP balances, potentially leading to pathology. Intriguingly, new 2H,3H-decafluoropentane-based oxygen-loaded nanodroplets (OLNDs) have proven effective in abrogating hypoxia-dependent dysregulation of MMP and TIMP secretion by single cell populations. This work explored the effects of different oxygen tensions and dextran-shelled OLNDs on MMP/TIMP production in an organized and multicellular tissue (term human placenta). Chorionic villous explants from normal third-trimester pregnancies were incubated with/without OLNDs in 3 or 20% O2. Explants cultured at higher oxygen tension released constitutive proMMP-2, proMMP-9, TIMP-1, and TIMP-2. Hypoxia significantly altered MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios enhancing TIMP-2 and reducing proMMP-2, proMMP-9, and TIMP-1 levels. Intriguingly, OLNDs effectively counteracted the effects of low oxygen tension. Collectively, these data support OLND potential as innovative, nonconventional, and cost-effective tools to counteract hypoxia-dependent dysregulation of MMP/TIMP balances in human tissues.
Cucumis sativus secretes 4′-ketoriboflavin under iron-deficient conditions
Authors: Satoh Junichi , Koshino Hiroyuki , Sekino Kouta , Ito Shinsaku , Katsuta Ryo , Takeda Kouji , Yoshimura Etsuro , Shinmachi Fumie , Kawasaki Shinji , Niimura Youichi , Nukada Tomoo
Published: November 2015

A new compound in cucumber, Cucumis sativus, nutrient solution that appears under iron-deficient conditions, but not under ordinary culture conditions, has been revealed by HPLC analysis. The chemical structure of this compound was identified using LC-MS and NMR techniques as that of 4′-ketoriboflavin. This is the first report to show that 4′-ketoriboflavin can be found in metabolites from organisms.
Nondestructive evaluation of photosynthesis by delayed luminescence in Arabidopsis in Petri dishes
Authors: Chuenwarin Paweena , Shimazaki Azumi , Shimizu Masanori , Kobayashi Yuko , Katsumata Masakazu , Kobayashi Hirokazu
Published: November 2015

Nondestructive evaluation of photosynthesis is a valuable tool in the field and laboratory. Delayed luminescence (DL) can reflect charge recombination through the backflow of electrons. However, DL detection has not yet been adapted for whole plants in Petri dishes. To compensate for differences in DL decay between sibling Arabidopsis plants grown under the same conditions, we developed a time-sequential double measurement method. Using this method, we examined the influence of photosynthetic electron flow inhibitors, and differences in the DL decay curves were categorized by considering the initial and late phases of the decay curves, as well as their intermediate slopes. The appearance of concavity and convexity in DL curves in Arabidopsis was different from unicellular algae, suggesting complexity in the photosynthetic machinery of higher plants. This detection method should be invaluable for evaluating photosynthetic defects in higher plants under sterile conditions without interrupting plant culture.
Elucidation of novel budding yeast separase mutants
Authors: Shimizu Yoshihito , Nagai Masayoshi , Yeasmin Akter M S T , Koike Naoki , Talukdar Muhammad Waliullah , Ushimaru Takashi
Published: November 2015

The mitotic separase cleaves Scc1 in cohesin to allow sister chromatids to separate from each other upon anaphase onset. Separase is also required for DNA damage repair. Here, we isolated and characterized 10 temperature-sensitive (ts) mutants of separase ESP1 in the budding yeast Saccharomyces cerevisiae. All mutants were defective in sister chromatid separation at the restricted temperature. Some esp1-ts mutants were hypersensitive to the microtubule poison benomyl and/or the DNA-damaging agent bleomycin. Overexpression of securin alleviated the growth defect in some esp1-ts mutants, whereas it rather exacerbated it in others. The Drosophila Pumilio homolog MPT5 was isolated as a high-dosage suppressor of esp1-ts cells. We discuss various features of separase based on these findings.
Cardiac autonomic response following high‐intensity running work‐to‐rest interval manipulation
Authors: Cipryan Lukas , Laursen Paul B. , Plews Daniel J.
Published: November 2015

The cardiorespiratory, cardiac autonomic (via heart rate variability (HRV)) and plasma volume responses to varying sequences of high‐intensity interval training (HIT) of consistent external work were investigated. Twelve moderately trained males underwent three HIT bouts and one control session. The HIT trials consisted of warm‐up, followed by 12 min of 15 s, 30 s or 60 s work:relief HIT sequences at an exercise intensity of 100% of the individual velocity at O2max (vO2max), interspersed by relief intervals at 60% O2max (work/relief ratio = 1). HRV was evaluated via the square root of the mean sum of the squared differences between R‐R intervals (rMSSD) before, 1 h, 3 h and 24 h after the exercise. Plasma volume was assessed before, immediately after, and 3 h and 24 h after. There were no substantial between‐trial differences in acute cardiorespiratory responses. The rMSSD values remained decreased 1 h after the exercise cessation in all exercise groups. The rMSSD subsequently increased between 1 h and 3 h after exercise, with the most pronounced change in the 15/15 group. There were no relationships between HRV and plasma volume. All HIT protocols resulted in similar cardiorespiratory responses with slightly varying post‐exercise HRV responses, with the 30/30 protocol eliciting the least disruption to post‐exercise HRV. These post‐exercise HRV findings suggest that the 30/30 sequence may be the preferable HIT prescription when the between‐training period is limited.
A Katsylo theorem for sheets of spherical conjugacy classes
Authors: Carnovale Giovanna , Esposito Francesco
Published: November 2015

We show that, for a sheet or a Lusztig stratum

S
S

containing spherical conjugacy classes in a connected reductive algebraic group

G
G

over an algebraically closed field in good characteristic, the orbit space

S

/

G

S/G

is isomorphic to the quotient of an affine subvariety of

G
G

modulo the action of a finite abelian

2
2

-group. The affine subvariety is a closed subset of a Bruhat double coset and the abelian group is a finite subgroup of a maximal torus of

G
G

. We show that sheets of spherical conjugacy classes in a simple group are always smooth and we list which strata containing spherical classes are smooth.
Radiation Physics and Radiation Safety
Authors: Murphy Paul H. , Galt James R.
Published: November 2015

One of the fundamental quests of nuclear cardiology is the search for elements with appropriate chemical properties for use in radiopharmaceuticals, which have radioactive isotopes that produce photons well suited for imaging, and deliver only a small radiation dose to the patient. This requires that that the emission of any radiation that does not contribute to the image be kept to a minimum and that the isotope remains radioactive only for a short period of time. Understanding the emission of radiation from atoms requires an understanding of atomic and nuclear structure and forces.
SPECT and PET Instrumentation
Authors: Garcia Ernest V. , Galt James R. , Chen Ji
Published: November 2015

Nuclear cardiac imaging is solidly based on many branches of science and engineering, including nuclear, optical and mathematical physics, electrical and mechanical engineering, chemistry and biology. This chapter uses principles from these scientific fields to provide an understanding of both the signals used, and the imaging system that captures these signals. Nuclear cardiology’s signals are the x-rays or ?-rays photons emitted from a radioactive tracer and its imaging systems are either single-photon emission computed tomography (SPECT) or positron emission tomography (PET) cameras. This combination has met with remarkable success in clinical cardiology. This success is due to the combination of sophisticated electronic nuclear instruments with a highly specific and thus powerful signal. The signal is as important as or more important than the imaging system. There is a misconception that cardiac magnetic resonance (CMR) cardiac computed tomography (CCT) and echocardiography are superior to nuclear cardiology imaging because of their superior spatial resolution. Yet, in detecting perfusion defects what is really necessary is superior contrast resolution. It is this superior contrast resolution that allows us to differentiate between normal and hypoperfused myocardium facilitating the visual analysis of nuclear cardiology perfusion images. Because these objects are bright compared to the background radioactivity, computer algorithms have been developed that allow us to automatically and objectively process and quantify our images. This chapter explains many of the important scientific principles necessary to understand nuclear cardiology imaging in general, i.e., how these sophisticated imaging systems detect the radiation emitted from the radiotracers.
Kinetics of Conventional and New Cardiac Radiotracers
Authors: Taillefer Raymond , Wackers Frans J. Th.
Published: November 2015

The kinetics of radiotracers, that is the mode of uptake, retention and release from the myocardium, are relevant for designing and implementing optimized nuclear cardiac imaging protocols. This chapter addresses the kinetics of commonly used radiotracers for imaging myocardial perfusion, sympathetic neuronal function and cardiac metabolism, both with SPECT and PET cardiac imaging. The optimal timing of imaging after injection either at stress or at rest is determined by rate of uptake in the heart and adjacent organs, as well as the residence time of radiotracers within the myocytes. The efficiency of myocardial extraction over a wide range myocardial blood flows is relevant for reliable detection of obstructive coronary artery disease and absolute quantification of regional myocardial blood flow. For each cardiac imaging agent the cellular mechanism of uptake and its release or retention are discussed with an emphasis on the clinical impact of these parameters.
Gated SPECT MPI Processing and Quantitation
Authors: Slomka Piotr J. , Germano Guido , Berman Daniel S.
Published: November 2015

Gated MPS provides an accurate and reproducible method for measuring myocardial perfusion at stress and rest as well as LVEF, EDV, ESV and diastolic function. It also provides a means of assessing regional wall motion abnormality, either at rest or post-stress. These functions and perfusion measurements obtained from gated MPS complement each other in CAD diagnosis as well as risk stratification. This chapter presents a comprehensive review of techniques used in gated SPECT processing to quantify function and perfusion, including the latest techniques and developments.
SPECT Attenuation Correction
Authors: Esteves Fabio Peroba , Galt James R.
Published: November 2015

Attenuation correction minimizes the impact of body habitus on the acquired myocardial count distribution. The superior diagnostic performance of corrected over uncorrected SPECT images is due to improved specificity and normalcy rate. The transmission image used for attenuation correction is obtained using CT or Gd-153 line sources. Artifactual defects may develop with attenuation correction if the transmission image is truncated, of poor count density, significantly contaminated by downscatter or misregistered with the emission image. Attenuation correction can help decrease the radiation exposure to the patient and improve the workflow in the nuclear laboratory by obviating the need for rest imaging on stress-first myocardial perfusion SPECT protocols. Coronary calcium on the CT attenuation image can add diagnostic and prognostic value to normal myocardial perfusion SPECT in patients without known coronary artery disease. Incidental noncardiac findings of potential clinical relevance are frequently found on the CT attenuation image and should be described on the clinical report.
Treadmill Exercise Testing
Authors: Turner Joshua A. , Brown Todd M.
Published: November 2015

Treadmill exercise testing is an important tool in the field of cardiology and is very commonly used because it is readily available, inexpensive, noninvasive, and provides pertinent diagnostic and prognostic information in assessing for the presence and severity of coronary artery disease (CAD). For decades, its primary use was to provoke and diagnose myocardial ischemia, but its clinical indications have become more numerous with time. In this chapter, we will review role of treadmill exercise testing in patients with known or suspected CAD, as well as the contraindications, complications, performance, interpretation, and its prognostics utility.
Gated SPECT Perfusion in Diagnosis and Risk Assessment in Stable Patients
Authors: Phillips Lawrence M. , Shaw Leslee J.
Published: November 2015

The chapter reviews the current evidence with regards to the diagnosis and prognosis of stress myocardial perfusion SPECT. Where relevant, we will also include selected series of patients undergoing stress myocardial perfusion PET. Readers of this chapter are also encouraged to examine recently published reviews on this subject. Additionally, there have been several recent expert consensus statements, clinical practice guidelines, and appropriate use criteria publications from the American College of Cardiology (ACC) and American Heart Association (AHA).
Risk Assessment in Acute Coronary Syndromes
Authors: AlJaroudi Wael
Published: November 2015

Acute coronary syndromes (ACS) include unstable angina pectoris (UAP), non-ST elevation (NSTEMI), and ST elevation acute myocardial infarction (STEMI). Each year, more than 2 million people are hospitalized with ACS in the United States. The initial treatment has evolved over the last few decades from conservative management to early reperfusion therapy. Medical therapy has also significantly changed with the use of newer more potent antiplatelet agents, beta-blockers, angiotensin converting enzyme inhibitors, statins, and anti-anginal drugs, which have resulted in improvement of patient care and survival. There is no role for stress myocardial perfusion imaging (MPI) in the acute presentation; however, rest MPI may be used to identify the culprit lesion and risk stratify patients if injected during chest pain. In stable patients for ACS, submaximal exercise or vasodilator MPI can be performed as early as 48 hours after the event. Several gated MPI-derived variables such as left ventricular (LV) ejection fraction (EF), LV volumes, infarct size, mechanical dyssynchrony, and residual ischemic burden can risk stratify patients and provide prognostic data incremental to validated clinical risk scores such as GRACE (Global Registry of Acute Coronary Syndrome) and TIMI (Thrombolysis in Myocardial Infarction). Patients with depressed LVEF, remodeled LV, and large perfusion defects are at particularly high- risk for subsequent cardiac death or recurrent myocardial infarction. In such setting, MPI plays a pivotal role in the management of patients and guiding therapeutic decisions. The current chapter will review the clinical and MPI predictors of outcomes in patients presenting with ACS according to updated guidelines and a proposed algorithm integrating the role of MPI in guiding therapeutic decisions and management.
Risk Assessment Before Noncardiac Surgery
Authors: AlJaroudi Wael
Published: November 2015

Perioperative risk assessment is essential in screening patients before noncardiac surgery. Cardiovascular complications such as fatal and non-fatal myocardial infarction (MI), ventricular arrhythmia, pulmonary edema, and stroke are important in-hospital causes of morbidity and mortality intra and post-operatively. The optimal approach is to identify patients at increased risk so that appropriate testing and therapeutic interventions are undertaken a priori to minimize such risk. The initial preoperative evaluation includes identification of surgery-specific risk, patient exercise functional capacity and clinical risk profile. Patients with major predictors of events such as acute coronary syndromes, recent MI, unstable arrhythmia, and severe valvular disease warrant further management and optimization that often lead to delaying surgery. Those with three or more predictors (history of ischemic heart disease, compensated heart failure, diabetes, renal insufficiency, or history of cerebrovascular disease) undergoing high- risk surgery often require stress testing. Although data from randomized prospective trials are lacking, numerous studies have demonstrated the utility of myocardial perfusion imaging (MPI) for determination of perioperative cardiac risk. The goal of this chapter is to review the use of MPI for preoperative risk assessment and the recommendations from the current guidelines. The focus will be on short-term and long-term prognosis including special groups such as after coronary stenting and before vascular surgery, liver and renal transplantation.
Myocardial Viability Assessment
Authors: Dilsizian Vasken , Valenta Ines , Schindler Thomas H.
Published: November 2015

Heart failure may be a consequence of ischemic or non-ischemic cardiomyopathy. Etiologies for LV systolic dysfunction in ischemic cardiomyopathy include; 1) transmural scar, 2) nontransmural scar, 3) repetitive myocardial stunning, 4) hibernating myocardium, and 5) remodeled myocardium. The LV remodeling process, which is activated by the renin-angiotensin system (RAS), stimulates toxic catecholamine actions and matrix metalloproteinases, resulting in maladaptive cellular and molecular alterations5, with a final pathway to interstitial fibrosis. These responses to LV dysfunction and interstitial fibrosis lead to progressive worsening of LV function. Established treatment options for ischemic cardiomyopathy include medical therapy, revascularization, and cardiac transplantation. While there has been continuous progress in the medical treatment of heart failure with beta-blockers, angiotensin-converting enzyme (ACE) inhibition, angiotensin II type 1 receptor (AT1R) blockers, and aldosterone to beneficially influence morbidity and mortality, the 5-years mortality rate for heart failure patients remains as high as 50%. Revascularization procedures include percutaneous transluminal coronary artery interventions (PCI) including angioplasty and endovascular stent placement and coronary artery bypass grafting (CABG). Whereas patents with heart failure due to non-coronary etiologies may best benefit from medical therapy or heart transplantation, coronary revascularization has the potential to improve ventricular function, symptoms, and long term survival, in patients with heart failure symptoms due to CAD and ischemic cardiomyopathy.
Inflammatory and Infiltrative Diseases and Tumors
Authors: Dorbala Sharmila , Nelson Katarina H.
Published: November 2015

This chapter highlights some of the novel clinical radionuclide imaging strategies beyond perfusion imaging including inflammatory diseases, infiltrative diseases and tumors. Targeted molecular imaging techniques to evaluate cardiac amyloidosis as well as myocardial and vascular inflammation are addressed. Clinical 18F-FDG imaging of cardiac sarcoidosis, cardiovascular prosthetic valve and device infections, systemic vasculitis, and tumors are discussed in detail. For each of these pathologies, a concise overview of the disease pathophysiology and management pertinent to understanding of imaging techniques is provided followed by details of imaging including radiotracers, imaging techniques and image interpretation with a reference to societal guidelines. The published data on the utility of radionuclide imaging tests to assess diagnosis, prognosis and to monitor response to therapy are discussed. Clinical scenarios and available societal recommendations on the use of imaging are illustrated. The strengths and limitations of radionuclide techniques are discussed in the context of a comparison to echocardiography, cardiac magnetic resonance imaging, cardiac CT and endomyocardial biopsy. Future directions in imaging and ongoing clinical trials in these areas are listed at the end of each section.
Guidelines and Appropriate Use Criteria
Authors: Marzouka George R. , Otalvaro-Orozco Lynda , Hendel Robert C.
Published: November 2015

Multiple documents have been published regarding the use of radionuclide imaging which attempt to outline the applications of SPECT and PET cardiac imaging and to offer guidance in not only how these techniques are performed but also when these tests should be used. These guidance documents, which include position papers, consensus documents, white papers, clinical practice guidelines (CPG), and appropriate use criteria (AUC) serve a number of purposes and are applicable to various health care providers. The focus of this chapter is on CPG and AUC, as these provide the basis for care optimization and reimbursement decisions and are the most widely accepted documents regarding radionuclide-imaging utilization. Throughout this book, each chapter has focused on the best practice of nuclear cardiology, emphasizing methods that will not only improve image quality but also provide significant clinical value. This chapter will emphasize the selection of patients for radionuclide imaging and focus on how best to use these resources to improve the outcome of patients with known or suspected heart disease.
Radiation Considerations
Authors: Einstein Andrew J.
Published: November 2015

Radiation considerations are an integral part of the practice of nuclear cardiac imaging. Concern regarding radiation has increased in recent years, reflected in statements by many professional societies, and likely attributable both to rapid growth in use of nuclear cardiology as well as high doses received by some nuclear cardiology patients. The fundamental principles of medical radiological protection are justification (ensuring that the right test is performed for the right patient at the right time), optimization (ensuring that the test is performed in the right manner), and dose limitation, which while applicable to healthcare workers is not operative regarding patients. Three "As" facilitate and serve as an organizing principle for justification: awareness, appropriateness, and audit. Awareness incorporates knowledge of the benefits and risks of testing involving radiation and effective communication of these to the patient. Appropriateness in nuclear cardiology can be assessed using the American College of Cardiology's appropriateness criteria. Methods that have been demonstrated to improve appropriateness include using a collaborative learning model, a point-of-order decision support tool, and a multifaceted intervention including threatened loss of insurance coverage. A variety of strategies should be considered for optimization to ensure patient-centered imaging. These including strategic selection of both the protocol, e.g. selecting a stress-first protocol and performing stress-only imaging in patients without a high pre-test probability of abnormal findings on stress imaging, or using PET, and also the administered activity, e.g. by using weight-based dosing and/or software- or hardware-based advances in camera technology. Special considerations are required for pregnant, nursing, and pediatric patients.