bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-time monitoring system of vortex wind field using coded acoustic wave signals between parallel array elements
Authors: Li Haiyue , Terada Hiroki , Yamada Akira
Published: June 2014

An acoustic travel-time tomography system for the monitoring of the vortex wind flow velocity profile has been studied, where multichannel parallel acoustic transmitter/receiver pairs are placed along opposite sides of the monitoring region. For real-time high-speed collection and computation of data, a simultaneous transmission technique of using a pseudo-noise code-modulation signal was adopted, as well as a graphics processing unit with the use of an 8-channel indoor test system, bidirectional travel time lag data along 34 propagation paths were processed in parallel. By this means, vortex wind fields, including their 2D center position, were successfully monitored at a frame rate of approximately 1 s. Real-time tracking capability for a moving vortex wind field was examined. The results showed the feasibility of the method for the monitoring of outdoor moving vortex wind fields.
ITCZ and ENSO pacing on East Asian winter monsoon variation during the Holocene: Sedimentological evidence from the Okinawa Trough
Authors: Zheng Xufeng , Li Anchun , Wan Shiming , Jiang Fuqing , Kao Shuh Ji , Johnson Cody
Published: June 2014

Deep‐sea fan sediments provide an excellent geological archive for paleoenvironment reconstruction. Grain size, clay mineral and elemental (Ti, Fe, Ca) compositions were measured for a core retrieved from a submarine fan in the Okinawa Trough. Varimax‐rotated Principal Component Analysis (V‐PCA) on time‐evolution of grain size spectrum reveals that, since the Holocene, sediment was transported mainly by the benthic nepheloid layer (33%) and upper layers (33%) which is driven by the East Asian winter monsoon (EAWM). The intensification of the Kuroshio Current during the Holocene, masks the fluvial signal of the summer monsoon and obstructs clay minerals derived from the Yellow River, a major contributor prior to 12 ka BP. A new grain size index (GSI), which represents the EAWM well, exhibits a negative correlation with the δ18O record in Dongge Cave, China during the Holocene when sea level was relatively steady. This anticorrelation suggests the southward migration of the Intertropical Convergence Zone (ITCZ). The consistency among our records and rainfall records in Peru, Ti counts in the Cariaco Basin, monsoon records in Oman and the averaged summer insolation pattern at 30°N further support the ITCZ's impact on monsoon systems globally. Cross‐Correlation Analyses for GSI and log(Ti/Ca) against δ18O record in Dongge Cave reveal a decoupling between the East Asian winter and summer monsoon during 5500–2500 cal yr BP, with greater complexity in the last 2500 years. This can be attributed to exacerbated ENSO mode fluctuations and possibly anthropogenic interference superimposed on insolation and ITCZ forcing.
Seasonal and interannual variability of carbon monoxide based on MOZAIC observations, MACC reanalysis, and model simulations over an urban site in India
Authors: Sheel Varun , Sahu L. K. , Kajino M. , Deushi M. , Stein O. , Nedelec P.
Published: June 2014

The spatial and temporal variations of carbon monoxide (CO) are analyzed over a tropical urban site, Hyderabad (17°27′N, 78°28′E) in central India. We have used vertical profiles from the Measurement of ozone and water vapor by Airbus in‐service aircraft (MOZAIC) aircraft observations, Monitoring Atmospheric Composition and Climate (MACC) reanalysis, and two chemical transport model simulations (Model for Ozone And Related Tracers (MOZART) and MRI global Chemistry Climate Model (MRI‐CCM2)) for the years 2006–2008. In the lower troposphere, the CO mixing ratio showed strong seasonality, with higher levels (>300 ppbv) during the winter and premonsoon seasons associated with a stable anticyclonic circulation, while lower CO values (up to 100 ppbv) were observed in the monsoon season. In the planetary boundary layer (PBL), the seasonal distribution of CO shows the impact of both local meteorology and emissions. While the PBL CO is predominantly influenced by strong winds, bringing regional background air from marine and biomass burning regions, under calm conditions CO levels are elevated by local emissions. On the other hand, in the free troposphere, seasonal variation reflects the impact of long‐range transport associated with the Intertropical Convergence Zone and biomass burning. The interannual variations were mainly due to transition from El Niño to La Niña conditions. The overall modified normalized mean biases (normalization based on the observed and model mean values) with respect to the observed CO profiles were lower for the MACC reanalysis than the MOZART and MRI‐CCM2 models. The CO in the PBL region was consistently underestimated by MACC reanalysis during all the seasons, while MOZART and MRI‐CCM2 show both positive and negative biases depending on the season.
Evaluation of sediment properties using wind and turbidity observations in the shallow tidal areas of the Venice Lagoon
Authors: Venier Chiara , D'Alpaos Andrea , Marani Marco
Published: June 2014

Sediment deposition and erosion by wind waves and tidal currents, mediated by bed sediment properties and by biostabilization/bioturbation, are key processes governing the dynamics of intertidal geomorphology. Here we develop and apply a method to estimate bed sediment properties, such as the settling velocity and the critical stress for erosion, providing a measure of the response of the system to the actual wave/tidal forcing. The method obtains estimates of sediment properties indirectly, by solving a sediment mass conservation equation for the water column, after explicitly modeling wave‐ and current‐induced bottom shear stresses. We apply this approach using meteorological, tidal, and turbidimetric data from a network of sensors in the Venice Lagoon, yielding estimates which compare favorably with existing observations of sediment properties. Advantages of the method are that it does not interfere with the biological and physical status of the sediment surface and that it makes use of commonly available weather and wave observations. The proposed method lends itself to the continuous monitoring of sediment parameters at the system scale with limited operational effort when the sediment suspended in the water column is mostly originated by local resuspension, such as in the case of wave‐dominated estuaries.
Modeling water demand when households have multiple sources of water
Authors: Coulibaly Lassina , Jakus Paul M. , Keith John E.
Published: June 2014

A significant portion of the world's population lives in areas where public water delivery systems are unreliable and/or deliver poor quality water. In response, people have developed important alternatives to publicly supplied water. To date, most water demand research has been based on single‐equation models for a single source of water, with very few studies that have examined water demand from two sources of water (where all nonpublic system water sources have been aggregated into a single demand). This modeling approach leads to two outcomes. First, the demand models do not capture the full range of alternatives, so the true economic relationship among the alternatives is obscured. Second, and more seriously, economic theory predicts that demand for a good becomes more price‐elastic as the number of close substitutes increases. If researchers artificially limit the number of alternatives studied to something less than the true number, the price elasticity estimate may be biased downward. This paper examines water demand in a region with near universal access to piped water, but where system reliability and quality is such that many alternative sources of water exist. In extending the demand analysis to four sources of water, we are able to (i) demonstrate why households choose the water sources they do, (ii) provide a richer description of the demand relationships among sources, and (iii) calculate own‐price elasticity estimates that are more elastic than those generally found in the literature.
Geostationary satellite observations of dynamic phytoplankton photophysiology
Authors: O'Malley Robert T. , Behrenfeld Michael J. , Westberry Toby K. , Milligan Allen J. , Shang Shaoling , Yan Jing
Published: June 2014

Since June 2010, the Geostationary Ocean Color Imager (GOCI) has been collecting the first diurnally resolved satellite ocean measurements. Here GOCI retrievals of phytoplankton chlorophyll concentration and fluorescence are used to evaluate daily to seasonal changes in photophysiological properties. We focus on nonphotochemical quenching (NPQ) processes that protect phytoplankton from high light damage and cause strong diurnal cycles in fluorescence emission. This NPQ signal varies seasonally, with maxima in winter and minima in summer. Contrary to expectations from laboratory studies under constant light conditions, this pattern is highly consistent with an earlier conceptual model and recent field observations. The same seasonal cycle is registered in fluorescence data from the polar‐orbiting Moderate Resolution Imaging Spectroradiometer Aqua satellite sensor. GOCI data reveal a strong correlation between mixed layer growth irradiance and fluorescence‐derived phytoplankton photoacclimation state that can provide a path for mechanistically accounting for NPQ variability and, subsequently, retrieving information on iron stress in global phytoplankton populations.
Ocean oxygen depletion due to decomposition of submarine methane hydrate
Authors: Yamamoto Akitomo , Yamanaka Yasuhiro , Oka Akira , Abe‐Ouchi Ayako
Published: June 2014

Global warming could decompose submarine methane hydrate and cause methane release into the ocean. The released methane causes oxygen depletion via oxidation; however, its global impact is yet to be quantitatively investigated. We have projected the potential impact of oxygen depletion due to methane hydrate decomposition via numerical modeling. We find that the global methane hydrate inventory decreases by approximately 70% (35%) under four times (twice) the atmospheric CO2 concentration and is accompanied by significant global oxygen depletion on a timescale of thousands of years. In particular, we demonstrate the great expansion of suboxic and hypoxic regions, having adverse impact on marine organisms and ocean biogeochemical cycles. This is because hydrate decomposition primarily occurs in the Pacific Ocean, where present‐day seawater has low oxygen concentration. Besides the decrease in oxygen solubility and reduced ventilation associated with global warming, the process described in this study is also important in oxygen depletion.
Dynamics of the Bingham Canyon Mine landslides from seismic signal analysis
Authors: Hibert Clément , Ekström Göran , Stark Colin P.
Published: June 2014

Joint interpretation of long‐ and short‐period seismic signals generated by landslides sheds light on the dynamics of slope failure, providing constraints on landslide initiation and termination and on the main phases of acceleration and deceleration. We carry out a combined analysis of the seismic signals generated by two massive landslides that struck the Bingham Canyon Mine pit on 10 April 2013. Inversion of the long‐period waveforms yields time series for the bulk landslide forces and momenta, from which we deduce runout trajectories consistent with the deposit morphology. Comparing these time series with the short‐period seismic data, we are able to infer when and where major changes take place in landslide momentum along the runout path. This combined analysis points to a progressive fracturing of the masses during acceleration indicates that deceleration starts the moment they reach the pit floor and suggests that the bulk movement is stopped by a topographic barrier.
How important are the alpha‐proton relative drift and the electron heat flux for the proton heating of the solar wind in the inner heliosphere?
Authors: Borovsky Joseph E. , Gary S. Peter
Published: June 2014

This report explores the feasibility of explaining the observed proton heating in the inner heliosphere (1) by tapping the field‐aligned relative drift between alpha particles and protons in the solar wind plasma and (2) by tapping the strahl‐electron heat flux from the Sun. The observed reduction of the alpha‐proton drift kinetic energy from 0.3 to 1 AU and the observed reduction of electron heat flux from 0.3 to 1 AU are each about half of the energy needed to account for the observed heating of protons from 0.3 to 1 AU. A mechanism is identified to transfer the free energy of the alpha‐proton relative drift into proton thermal energy: the alpha‐proton magnetosonic instability. A mechanism is identified to transfer kinetic energy from the strahl‐electron heat flux into proton thermal energy: weak double layers. At the current state of knowledge, the plausibility of heating the solar wind protons via the alpha‐proton magnetosonic instability is high. The properties of the weak double layers that have been observed in the solar wind are not well known; more data analysis and plasma simulations are needed before the plausibility of heating the solar wind protons by the double‐layer mechanism can be evaluated.
Pulse properties of terrestrial gamma‐ray flashes detected by the Fermi Gamma‐Ray Burst Monitor
Authors: Foley S. , Fitzpatrick G. , Briggs M. S. , Connaughton V. , Tierney D. , McBreen S. , Dwyer J. R. , Chaplin V. L. , Bhat P. N. , Byrne D. , Cramer E. , Fishman G. J. , Xiong S. , Greiner J. , Kippen R. M. , Meegan C. A. , Paciesas W. S. , Preece R. D. , von Kienlin A. , Wilson‐Hodge C.
Published: June 2014

The Gamma‐ray Burst Monitor (GBM) on board the Fermi Gamma‐ray Space Telescope has triggered on over 300 terrestrial gamma‐ray flashes (TGFs) since its launch in June 2008. With 14 detectors, GBM collects on average ∼100 counts per triggered TGF, enabling unprecedented studies of the time profiles of TGFs. Here we present the first rigorous analysis of the temporal properties of a large sample of TGFs (278), including the distributions of the rise and fall times of the individual pulses and their durations. A variety of time profiles are observed with 19% of TGFs having multiple pulses separated in time and 31 clear cases of partially overlapping pulses. The effect of instrumental dead time and pulse pileup on the temporal properties are also presented. As the observed gamma ray pulse structure is representative of the electron flux at the source, TGF pulse parameters are critical to distinguish between relativistic feedback discharge and lightning leader models. We show that at least 67% of TGFs at satellite altitudes are significantly asymmetric. For the asymmetric pulses, the rise times are almost always shorter than the fall times. Those which are not are consistent with statistical fluctuations. The median rise time for asymmetric pulses is ∼3 times shorter than for symmetric pulses while their fall times are comparable. The asymmetric shapes observed are consistent with the relativistic feedback discharge model when Compton scattering of photons between the source and Fermi is included, and instrumental effects are taken into account.
Extent of ECH wave emissions in the Earth's magnetotail
Authors: Zhang Xiaojia , Angelopoulos Vassilis , Ni Binbin , Thorne Richard M. , Horne Richard B.
Published: June 2014

The exact role of electrostatic electron cyclotron harmonic (ECH) waves in driving diffuse aurora has been controversial for many years. Using THEMIS observations from five magnetotail seasons, we investigate the occurrence rate distribution of ECH waves and the extent of individual wave intensifications under various plasma sheet conditions. Both are critical for modeling these waves' contributions to electron scattering and to diffuse auroral emissions. Single‐spacecraft data analysis shows that ECH waves occur frequently in the midnight and postmidnight magnetotail and that their occurrence rates decrease with increasing radial distance from Earth. More than 50% of ECH wave events (continuous intervals of wave activity) occur during local plasma sheet activations, evidenced by energetic electron injections and dipolarization fronts. Excluding ECH wave emissions concurrent with such local plasma sheet activations (known to peak in occurrence rate near premidnight), we find that quiet plasma sheet ECH wave emissions exhibit preference for dawn. This preference suggests a close relationship between these waves and the drift paths of injected electrons. Dual‐spacecraft data analysis shows that the Z‐extent is ~0.5 RE, the Y‐extent is ~2 RE, and the X‐extent is at least 4 RE. During locally quiet plasma sheet conditions, ECH waves exhibit a smaller Z‐ and X‐extent, but the Y‐extent is similar during all the conditions. In order to investigate the mechanism leading to the different Z‐extents under various plasma sheet conditions, we use ray tracing to model the wave power distribution as a function of distance from the neutral sheet. We find a linear correlation between the wave Z‐extent and field line curvature radius (Rc). A Z‐extent of ~0.2 RE (consistent with observations) corresponds to Rc~0.9 RE. Our results suggest that ECH intensification following dipolarizing flux bundles is in part due to increased Rc, which enables intensification to higher amplitudes over a larger volume, explaining the increased occurrence rate and extent of active‐time wave events.
Effects of heterogeneous soil‐water diffusivity on vegetation pattern formation
Authors: Yizhaq H. , Sela S. , Svoray T. , Assouline S. , Bel G.
Published: June 2014

Many mathematical models have been proposed to explain the emergence of vegetation patterns in arid and semiarid environments, but only a few of them take into account the heterogeneity in the system properties. Here we present a rigorous study of the effects of heterogeneous soil‐water diffusivity on vegetation patterns, using two mathematical models. The two models differ in the pattern‐forming feedback that they capture; one model captures the infiltration contrast between vegetated and bare‐soil domains, whereas the other model captures the increased growth rate of denser vegetation due to an enhanced ability to extract water from the soil. In both models, the most significant effect of the heterogeneity on the soil‐water diffusivity is the increased durability of patterned vegetation to a reduced precipitation rate. An additional effect is that the heterogeneity makes the desertification process, namely, the transition from a spotted vegetation pattern to a bare‐soil state, more gradual than in the homogeneous system. Our findings suggest that the heterogeneity cannot be neglected in the study of critical transitions in heterogeneous ecosystems and, particularly, in the study of the desertification process due to climate changes or anthropogenic disturbances.
A Hybridized Local and Charge‐Transfer Excited State for Highly Efficient Fluorescent OLEDs: Molecular Design, Spectral Character, and Full Exciton Utilization
Authors: Li Weijun , Pan Yuyu , Yao Liang , Liu Haichao , Zhang Shitong , Wang Chu , Shen Fangzhong , Lu Ping , Yang Bing , Ma Yuguang
Published: June 2014

For a donor–acceptor (D–A) molecule, there are three possible cases for its low‐lying excited state (S1): a π–π* state (a localized electronic state), a charge‐transfer (CT) state (a delocalized electronic state), and a mixed or hybridized state of π–π* and CT (named here as the hybridized local and charge transfer (HLCT) state). The HLCT state is an important excited state for the design of next‐generation organic light‐emitting diode (OLED) materials with both high photoluminescence (PL) efficiency and a large fraction of singlet exciton generation in electroluminescence (EL). According to the principle of state mixing in quantum chemistry, a series of twisting D–A molecules are designed and synthesized, and their HLCT state characters are verified by both fluorescent solvatochromic experiments and quantum chemical calculations. The CT components in the HLCT state, which greatly affect the molecular optical properties, are found to be enhanced with a decrease of the twist angle of the D–A segment or an increase of the D–A intensity in these twisting D–A molecules. In OLEDs, using these HLCT compounds as the emitting layer, the maximum exciton utilization efficiency is harvested up to 93%. Surprisingly, an exception of Kasha's rule is revealed in some HLCT compounds: restricted internal‐conversion (IC) from the high‐lying triplet state (T2) to the low‐lying triplet T1, and a reopened path of reverse intersystem crossing (RISC) from T2to S1or S2, based on the analysis of the excited‐state energy levels and the measurement of the low‐temperature spectrum. RISC from T2to S1(S2) as a “hot exciton” channel is believed to contribute to the large proportion of the radiative singlet excitons.
Design of Superhydrophobic Porous Coordination Polymers through the Introduction of External Surface Corrugation by the Use of an Aromatic Hydrocarbon Building Unit
Authors: Rao Koya Prabhakara , Higuchi Masakazu , Sumida Kenji , Furukawa Shuhei , Duan Jingui , Kitagawa Susumu
Published: June 2014

We demonstrate a new approach to superhydrophobic porous coordination polymers by incorporating an anisotropic crystal morphology featuring a predominant surface that is highly corrugated and terminated by aromatic hydrocarbon moieties. The resulting low‐energy surface provides particularly promising hydrophobic properties without the need for postsynthetic modifications or surface processing that would block the porosity of the framework. Consequently, hydrophobic organic molecules and water vapor are able to penetrate the surface and be densely accommodated within the pores, whereas bulk water is repelled as a result of the exterior surface corrugation derived from the aromatic surface groups. This study provides a new strategy for the design and development of superhydrophobic porous materials.
Aromatic Versus Heteroradialene Character in Extended Thiophloroglucinol Ligands and their Trinuclear Nickel(II) Complexes
Authors: Feldscher Bastian , Stammler Anja , Bögge Hartmut , Glaser Thorsten
Published: June 2014

Extended phloroglucinol ligands and complexes are best described as nonaromatic heteroradialenes. Herein, the electronic structures of extended thiophloroglucinol ligands and their NiII3 complexes are evaluated by comparison to their phloroglucinol analogs by means of NMR, FTIR, UV/Vis, and structural parameters. To provide a full set of compounds for this comparison of S versus O substitution, a new triplesalen ligand, its NiII3 complex, and a new thiophloroglucinol were synthesized. 1H and 15N NMR chemical shifts and coupling constants prove that the thiophloroglucinol ligands exist as the N‐protonated and not the O‐protonated tautomer. 13C and 15N NMR chemical shifts and structural parameters further demonstrated that the extended thiophloroglucinol ligands must be described with a predominant thione‐enamine (heteroradialene) character despite the participation of a CS double bond. In the NiII3 complexes, this heteroradialene character is reduced but still predominant.
An overview to understand the role of PE_PGRS family proteins in Mycobacterium tuberculosisH37Rv and their potential as new drug targets
Authors: Meena Laxman S.
Published: June 2014

Tuberculosis has long been the scourge of humanity, claiming millions of lives. The family of PE_PGRS gene has been attributed to the Mycobacterium tuberculosis pathogenesis over the past few decades. The gene of PE_PGRS family proteins are most often clustered in a region of the genome often as overlapping genes and role in cell surface markers, adhesion and invasion of defense cells of the host (macrophage and dendritic cells). The proline–glutamic acid (PE) domain is responsible for the cellular localization of these proteins on bacterial cells. This gene family shows immense genetic variability in terms of multiple insertion–deletions and single‐nucleotide polymorphisms as seen in PE_PGRS9, PE_PGRS17, PE_PGRS18, and PE_PGRS33. In spite of variability, there are indications of shared epitopes in these proteins. Few of these gene sequences that have been studied from evolutionary perspective show indication of positive selection and also landmarks of recent evolutionary events. Many of these proteins show calcium‐binding motifs and consequently seen to be responsible in inhibition of phagolysosome formation via a calmodulin‐kinase‐dependent pathway. A number of PE_PGRS genes were tested for its expression with different growth conditions in vitro and in vivo, among which the contrast in expressivity was seen vividly in PE_PGRS16 (upregulated) and PE_PGRS26 (downregulated) in bacteria persisting in macrophages. Similarly, PE_PGRS33 has been indicated in macrophagial necrosis by a tumor necrosis factor‐α‐induced pathway. These PE_PGRS family genes may be an interesting subject for research and development. Their fibronectin‐binding and calcium‐binding property may be strongly implicated in immunopathogenesis of virulent M. tuberculosis strain. In this review, an attempt has been made to evaluate and present data for better understanding of in vivo pathogen functions, for understanding the physiological significance of PE_PGRS gene family, and their potential as new drug targets.
Determination of vitamin B6 using an optimized novel TCPO–indolizine–H2O2 chemiluminescence system
Authors: Chaichi M. J. , Ehsani M. , Asghari S. , Behboodi V.
Published: June 2014

Indolizine derivatives are of great interest as fluorescent emitters for peroxyoxalate chemiluminescence. The reaction of peroxyoxalates such as bis‐(2,4,6‐trichlorophenyl) oxalate (TCPO) with H2O2 can transfer energy to fluorescer via the formation of dioxetanedione intermediate. Four indolizine derivatives were used as a novel fluorescer in the chemiluminescence (CL) systems in this study. The relationship between CL intensity and the concentration of fluorescer, peroxyoxalate, sodium salicylate and hydrogen peroxide was investigated. Optimum conditions were obtained for four fluorescers and it was found that the indolizine can be used as an efficient green fluorescence emitter. Vitamin B6 induces a sharp decrease in the CL intensity of the TCPO–hydrogen peroxide–sodium salicylate system. A simple, rapid and sensitive CL method for the determination of vitamin B6 has been developed. The results showed a linear relationship between vitamin B6 concentration and peroxyoxalate CL intensity in the range 7.0 × 10−8–1.0 × 10−4. A detection limit of 2.3 × 10−8 M and relative standard deviation (RSD) of < 4.5% were obtained. Copyright © 2014 John Wiley & Sons, Ltd.
Genetic Encoding of Caged Cysteine and Caged Homocysteine in Bacterial and Mammalian Cells
Authors: Uprety Rajendra , Luo Ji , Liu Jihe , Naro Yuta , Samanta Subhas , Deiters Alexander
Published: June 2014

We report the genetic incorporation of caged cysteine and caged homocysteine into proteins in bacterial and mammalian cells. The genetic code of these cells was expanded with an engineered pyrrolysine tRNA/tRNA synthetase pair that accepts both light‐activatable amino acids as substrates. Incorporation was validated by reporter assays, western blots, and mass spectrometry, and differences in incorporation efficiency were explained by molecular modeling of synthetase–amino acid interactions. As a proof‐of‐principle application, the genetic replacement of an active‐site cysteine residue with a caged cysteine residue in Renilla luciferase led to a complete loss of enzyme activity; however, upon brief exposure to UV light, a >150‐fold increase in enzymatic activity was observed, thus showcasing the applicability of the caged cysteine in live human cells. A simultaneously conducted genetic replacement with homocysteine yielded an enzyme with greatly reduced activity, thereby demonstrating the precise probing of a protein active site. These discoveries provide a new tool for the optochemical control of protein function in mammalian cells and expand the set of genetically encoded unnatural amino acids.
Using Chemistry to Investigate the Molecular Consequences of Protein Ubiquitylation
Authors: Abeywardana Tharindumala , Pratt Matthew R.
Published: June 2014

Chemistry has long played an indispensable role in biological discovery through the synthesis of homogeneous, structurally defined material. With continuing advances in the area of synthetic protein chemistry, chemists are able to prepare increasingly large and complex proteins that have enabled key biochemical experiments. Here, we describe some of the chemical methods that have been applied to the synthesis of ubiquitylated proteins, as ubiquitylation is a crucial post‐translational modification that mediates a variety of important biological effects on substrate proteins.
Percutaneous closure of the aortic valve as a bridge to heart transplantation to treat severe aortic insufficiency after ventricular assist device
Authors: Sauer Andrew J. , Davidson Charles J. , McGee Edwin C.
Published: June 2014

Aortic insufficiency (AI) following rotary left ventricular assist device (LVAD) implantation is an increasingly common problem with inadequately defined treatment options. Percutaneous transcatheter (PTC) closure of the aortic valve (AV) has been described as a potential nonsurgical approach. Alternatively, we present a case of decompensated heart failure due to de novo severe AI following LVAD in which successful PTC closure of the AV resolved the severe AI and allowed for clinical recovery and stability for more than 10 months as a bridge to heart transplantation. © 2014 Wiley Periodicals, Inc.
Prevalence and predictors of carotid artery stenosis in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation
Authors: Steinvil Arie , Leshem‐Rubinow Eran , Abramowitz Yigal , Shacham Yacov , Arbel Yaron , Banai Shmuel , Bornstein Natan M. , Finkelstein Ariel , Halkin Amir
Published: June 2014

Objectives

Our aim was to analyze the prevalence and predictors of Carotid artery stenosis (CAS) in patients undergoing transcatheter aortic valve implantation (TAVI).

Background

CAS is associated with the risk of periprocedural stroke in patients undergoing cardiac surgery. However, little is known about the prevalence of and clinical significance of CAS in the setting of TAVI.

Methods

Consecutive patients undergoing a carotid Doppler study the day before TAVI were followed prospectively. CAS was defined in accordance with current practice guidelines. Logistic regression models were used to identify independent correlates of CAS.

Results

The study included 171 patients (age 82 ± 6, male gender 47%). Carotid atherosclerosis (CA, defined as any carotid plaque) was present in 164 (96%) of patients, and CAS (peak systolic velocity [PSV] ≥ 125 cm/sec; ≥50% diameter stenosis) in 57 (33%) patients. Severe CAS (PSV ≥ 230 cm/sec; ≥70% stenosis, or near occlusion) was found in 15 (9%) patients. By multivariate analysis, smoking and a higher Euroscore independently predicted the presence of CAS. Patients in the present TAVI cohort had a significantly higher prevalence of both unilateral and bilateral CAS ≥ 50% than those in a previously reported cohort (n = 494 patients, age ≥ 70) undergoing clinically driven coronary angiography (33% vs. 20%, OR = 1.9, P = 0.001; and, 13% vs. 6%, OR = 2.3, P = 0.003, respectively). CAS was not independently associated with 30‐day mortality or stroke rates.

Conclusions

The prevalence of CAS in patients undergoing TAVI is high, exceeding that observed in patients undergoing catheterization for coronary indications. The impact of CAS on clinical outcomes following TAVI merits further research. © 2014 Wiley Periodicals, Inc.
Neo‐annulus: A reference plane in a surgical heart valve to facilitate a valve‐in‐valve procedure
Authors: Bapat Vinayak , Adams Benjamin , Attia Rizwan , Noorani Alia , Thomas Martyn
Published: June 2014

Objectives

To determine the level of the narrowest plane (neo‐annulus) of a surgical heart valve (SHV), which could be used for sizing and securing a transcatheter heart valve (THV) during a valve‐in‐valve (VIV) procedure and define its relationship with the fluoroscopic markers of the SHV.

Background

In the native aortic valve, the aortic annulus is used as a reference plane for sizing and deployment of THV as it provides the narrowest dimension to securely anchor the THV. However, the reference level for different models of SHV that are currently treated by a VIV procedure remains unknown.

Methods

We studied 13 aortic SHVs from all major heart valve manufacturers (labeled size 21, 22, or 23). A 26cc valvuloplasty balloon was inflated with contrast within each SHV under fluoroscopy to achieve a ‘waist’. The level of the ‘waist’ was compared with the SHV and its fluoroscopic markers to identify the level of the neo‐annulus.

Results

In all SHVs tested, the balloon ‘waist’ or ‘neo‐annulus’ was at the level of the sewing ring. When the fluoroscopic marker of the SHV was the sewing ring, the level of the neo‐annulus was also at that level, irrespective of supra‐annular or intra‐annular design. However, when the fluoroscopic marker was the stent frame, the relationship between the fluoroscopic marker and the level of the neo‐annulus was different for supra‐annular and intra‐annular designs. This correlation was not possible in two models of SHV as neither the stent nor the sewing ring was radio‐opaque.

Conclusions

We have demonstrated that the narrowest portion of all SHVs is at the level of its sewing ring, which can be identified fluoroscopically and should be used as a reference level during a VIV procedure. © 2014 Wiley Periodicals, Inc.
Transcatheter embolization of a large aneurysm in a congenital coronary cameral fistula from the left coronary artery to the right ventricle
Authors: Freund Jan Erik , Yuko‐Jowi Christine , Freund Matthias W.
Published: June 2014

A congenital coronary cameral fistula (CCCF) is characterized by left ventricular dysfunction, electrocardiographic changes due to a reduced left coronary blood flow and impaired physical activity. CCCF's with a giant aneurysm are very rarely seen. The presence of a giant aneurysm imposes even greater health risks. We report a case of a CCCF from the left coronary artery to the right ventricle with a large distal aneurysm in a 20‐year‐old woman that we closed percutaneously with coils for the closure of ventricular septal defects (VSD) and persistent ductus arteriosus (PDA). © 2014 Wiley Periodicals, Inc.
Resolution of inferior venous baffle leak and total venous occlusion using a bare stent and the gore® excluder ® aortic extension in transposition of the great arteries after mustard procedure
Authors: Ross Michael M. , Schamberger Marcus S. , Hoyer Mark H.
Published: June 2014

We present a patient with a history of Mustard repair for transposition of the great arteries. The patient presented with complete inferior venous baffle obstruction and a large baffle leak after several years of cyanosis. Complete relief of the obstruction and exclusion of the baffle leak were accomplished with the use of a combination of bare metal stenting and the Gore® Excluder® aortic extender. To our knowledge, this represents the first reported use of the Gore® Excluder® aortic extender in the setting of inferior venous baffle leak and associated total inferior vena cava obstruction. © 2015 Wiley Periodicals, Inc.
Cell‐level modeling of nutrient competition on the growth of microalgal biomass
Authors: Fleming Steven David , Vogt Frank
Published: June 2014

Growth of microalgal biomass is driven by nutrient availability but also by species competition for these nutrients. In this study, a modeling procedure has been developed by means of which impacts of nutrient competition on microalgae cells can be investigated on a cell‐level. The goal of this modeling is to enhance the understanding of nutrient competition in a given biological environment and to enable predicting the biomass' species composition. These models are compared with experimental data and empirical assessments published earlier in this journal. Because these simulations have been built on very generic assumptions, transferring this chemometric methodology to other cell types is straightforward. Copyright © 2014 John Wiley & Sons, Ltd.
Competitive Reaction Pathways for the Gas‐Phase Reactivity of [Me2AlNH2]3
Authors: Davydova Elena I. , Frenking Gernot , Timoshkin Alexey Y.
Published: June 2014

Reaction energy profiles for [Me2AlNH2]3 have been computationally explored by using density functional theory. Both intra‐ and intermolecular methane elimination reactions, as well as AlN bond‐breaking pathways, were considered. The results show that the energy required for AlN bond breaking in cyclic [Me2AlNH2]3 is of the same order of magnitude as the activation energies for the first (limiting) step of methane elimination (for both mono‐ and bimolecular mechanisms). Thus, dissociative and associative reaction pathways are competitive. Low‐temperature/high‐pressure conditions will favor the bimolecular pathway, whereas at high temperatures, either intramolecular methane elimination or AlN bond‐breaking dissociative pathways will be operational.
Selective Hydrodeoxygenation of Cyclic Vicinal Diols to Cyclic Alcohols over Tungsten Oxide–Palladium Catalysts
Authors: Amada Yasushi , Ota Nobuhiko , Tamura Masazumi , Nakagawa Yoshinao , Tomishige Keiichi
Published: June 2014

Hydrodeoxygenation of cyclic vicinal diols such as 1,4‐anhydroerythritol was conducted over catalysts containing both a noble metal and a group 5–7 transition‐metal oxide. The combination of Pd and WOx allowed the removal of one of the two OH groups selectively. 3‐Hydroxytetrahydrofuran was obtained from 1,4‐anhydroerythritol in 72 and 74 % yield over WOx–Pd/C and WOx–Pd/ZrO2, respectively. The WOx–Pd/ZrO2 catalyst was reusable without significant loss of activity if the catalyst was calcined as a method of regeneration. Characterization of WOx–Pd/C with temperature‐programmed reduction, X‐ray diffraction, and transmission electron microscopy/energy‐dispersive X‐ray spectroscopy suggested that Pd metal particles approximately 9 nm in size were formed on amorphous tungsten oxide particles. A reaction mechanism was proposed on the basis of kinetics, reaction results with tungsten oxides under an atmosphere of Ar, and density functional theory calculations. A tetravalent tungsten center (WIV) was formed by reduction of WO3 with the Pd catalyst and H2, and this center served as the reductant for partial hydrodeoxygenation.
Promising Aquivion Composite Membranes based on Fluoroalkyl Zirconium Phosphate for Fuel Cell Applications
Authors: Donnadio Anna , Pica Monica , Subianto Surya , Jones Deborah J. , Cojocaru Paula , Casciola Mario
Published: June 2014

Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short‐side‐chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt % show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY) are observed for the 10 wt % ZPR membrane: ΔE/E up to 90 % and ΔσY/σY up 70 % at 70 °C and 80 % relative humidity (RH). In the RH range 50–95 %, the in‐plane conductivity of the composite membranes reaches 0.43 S cm−1 for 10 wt % ZPR at 110 °C and is on average 30 % higher than the conductivity of the pristine PFSA. The 10 wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50 % RH but becomes progressively less hydrated with increasing RH both at 80 and 110 °C. The fuel cell performance of this membrane, at 80 °C and 30 % RH, is better than that of the unmodified PFSA.
Diagnostic yield of ThinPrep preparation in the assessment of fine‐needle aspiration biopsy of salivary gland neoplasms
Authors: Hipp Jennifer , Lee Beatrice , Spector Matthew E. , Jing Xin
Published: June 2014

Background

Fine‐needle aspiration (FNA) has been widely recognized as an important modality in assessment of salivary gland neoplasms, and specimens are often processed as conventional smears. We conducted the current study to evaluate the diagnostic utility of ThinPrep preparation as an alternative method for assessment of salivary gland neoplasms.

Methods

A computer SNOMED search from the pathology database at our institution between July 1999 and June 2012 was conducted to identify FNA cytology specimens of salivary gland lesions for which follow‐up surgical specimens revealed neoplasms. The FNA specimens were divided into two cohorts: one cohort consisted solely of the specimens in which all needle passes were collected into CytoLyt solution and only ThinPrep slides were prepared; and the other cohort included the specimens prepared with conventional smears. Diagnostic performance of the two cohorts was compared.

Results

Nondiagnostic rate of ThinPrep preparation was significantly higher than that of conventional smears (40% vs.18%; P <0.001). Among the diagnostic specimens, although more indeterminate diagnoses were generated in ThinPrep preparation compared to conventional smears (40% vs. 26%; P = 0.024), absolute cytohistologic concordant rate for the positive cases (type of neoplasms specified) is similar between the two preparations (80% vs. 86%; P = 0.354). Furthermore, there is no significant difference in rate of accurate diagnosis (correct typing of benign versus malignant neoplasm) between the two preparations (70% vs. 81%; P = 0.057).

Conclusions

ThinPrep may be considered as another practical method of specimen preparation in the assessment of salivary gland neoplasms, particularly when FNA is performed without immediate assistance from cytology. Diagn. Cytopathol. 2015;43:98–104. © 2014 Wiley Periodicals, Inc.
Sulfonated Polymethylsiloxane as an Additive for Selective Calcium Oxalate Crystallization
Authors: Neira‐Carrillo Andrónico , Luengo‐Ponce Fabian , Vásquez‐Quitral Patricio , Yazdani‐Pedram Mehrdad , Fernández María Soledad , Cölfen Helmut , Arias José Luis
Published: June 2014

Sulfonated and fluorescent polymethylsiloxanes (SO3H‐PMS) were synthesized, and their effect as additives on in vitro calcium oxalate (CaOx) crystallization was evaluated. SO3H‐PMS was prepared by hydrosilylation and sulfonation reactions with poly(dimethylsiloxane‐co‐hydrogenmethylsiloxane) (PDMS‐co‐PMHS). Several analytical tools were used to investigate the morphology, crystal structure, and chemical contents of the harvested CaOx crystals. Varying the concentration of SO3H‐PMS induces a transition of CaOx monohydrate (COM) with expanded multilayer and circular stacked‐sheet morphologies as well as of the bipyramidal CaOx dihydrate (COD) crystals in three crystallization procedures. Energy‐dispersive X‐ray spectroscopy (EDS) and XRD allowed detecting the presence of Si (0.2–1.0°wt.‐%), which stems from SO3H‐PMS adsorbed on CaOx, and the selective formation of phases of COM and COD. We demonstrated that the presence of anionic moieties on the SO3H‐PMS backbone and their concentration were crucial to control the crystal type, morphology, crystal size, and chemical composition.
Solid‐State NMR Characterization of Paramagnetic Bis(L‐valinato)copper(II) Stereoisomers – Effect of Conformational Disorder and Molecular Mobility on 13C and 2H Fast Magic‐Angle Spinning Spectra
Authors: Szalontai Gábor , Sabolović Jasmina , Marković Marijana , Szabolcs Balogh and
Published: June 2014

The solid‐state 13C and 2H NMR spectra of paramagnetic anhydrous trans‐bis(L‐valinato)copper(II) and cis‐aquabis(L‐valinato)copper(II) complexes have been obtained. Under the very fast MAS conditions, both the 13C and 2H MAS spectra were well enough resolved to allow the easy distinction between the trans and cis stereoisomers. The conformational disorder observed previously in the X‐ray structure of the cis isomer was also reflected in the 13C and 2H MAS spectra. Variable‐temperature 2H MAS spectra of differently deuterated ligand species, that is, the copper(II) complexes with L‐[D2]valine, L‐[D8]valine, and L‐[D10]valine, suggested the dynamic nature of this disorder in the aqua cis isomer and confirmed static ND2 deuterons in the anhydrous trans isomer. Quantum chemical DFT/B3LYP calculations of the 13C hyperfine (Fermi contact) shifts of the paramagnetic term were useful as assignment aids in the interpretation of the 13C MAS spectra.
Coexistence of Localized and Itinerant Electrons in the Double‐Perovskite Ba2Fe2/3Mo4/3O6
Authors: López Carlos A. , Saleta Martín E. , Pedregosa José C. , Sánchez Rodolfo D. , Alonso José A. , Fernández‐Díaz María T.
Published: June 2014

A polycrystalline Ba2Fe2/3Mo4/3O6 double‐perovskite has been prepared by decomposition of citrate precursors and subsequent thermal treatment under a reducing atmosphere. The crystal structure has been studied by combined X‐ray and neutron powder diffraction (XRPD and NPD). At room temperature, the structure is cubic (Fm$\bar {3}$m) with lattice parameter a = 8.0710(1) Å. It is unchanged between 3 and 320 K. The crystallographic formula is Ba2[Fe0.52(2)Mo0.48(2)]4a[Fe0.14(2)Mo0.86(2)]4bO5.9(2). NPD, electron spin resonance (ESR), and magnetization measurements show spontaneous magnetization below the Curie temperature (TC) = 310 K. The ESR behavior is associated with the presence of localized Fe3+ ions, whereas the transport properties (electrical conductivity and Seebeck effect) suggest the presence of highly correlated electrons in a metallic band with disorder, which can be associated with the Mo t2g electrons. The coexistence of localized and itinerant electrons leads to non‐negligible magnetoresistance properties.
New Members of a Class of Monomeric {Fe(NO)2}10 Dinitrosyliron Complexes and a Dimeric {Fe(NO)2}10–{Fe(NO)2}10 Dinitrosyliron Complex
Authors: Lo Feng‐Chun , Ho Yi‐Chieh , Chang Po‐Ya , Lee Gene‐Hsiang , Kuo Ting‐Shen , Chen Jeng‐Lung , Chen Chien‐Hong
Published: June 2014

The monomeric {Fe(NO)2}10 dinitrosyliron complexes (DNICs) [K‐18‐crown‐6‐ether][(NO)2Fe(NC9H6‐NH)] (1), [K‐18‐crown‐6‐ether][(NO)2Fe(NC9H6‐O)] (2), and [K‐18‐crown‐6‐ether][(NO)2Fe(NC9H6‐S)] (3) containing [N,NH], [N,O], and [N,S] ligations were synthesized by displacing the N,N,N′,N′‐tetramethylethylenediamine (tmeda) group of {Fe(NO)2}10 (tmeda)Fe(NO)2 with quinolin‐8‐amide, quinolin‐8‐olate, and quinolin‐8‐thiolate, respectively. Anionic {Fe(NO)2}10 DNICs 1–3 were characterized by IR, 1H NMR, and UV/Vis spectroscopy and single‐crystal X‐ray diffraction. The binding affinity of the ligands (i.e., [NC9H6NH]–, [NC9H6O]–, and [NC9H6S]–) toward the {Fe(NO)2}10 fragment was also investigated, and ligand substitution was found to follow the order [NC9H6S]– > [NC9H6O]– > [NC9H6NH]–. Displacement of the tmeda group of (tmeda)Fe(NO)2 by [K‐18‐crown‐6‐ether][SC6H4‐o‐NH2] and [PPh4][SC6H4‐o‐NH2] afforded monomeric {Fe(NO)2}10 DNIC [K‐18‐crown‐6‐ether][(NO)2Fe(SC6H4‐o‐NH2)] (4) and dimeric {Fe(NO)2}10–{Fe(NO)2}10 DNIC [PPh4]2[(NO)2Fe(μ‐SC6H4‐o‐NH2)]2 (5), respectively. The function of the countercation in the formation of monomeric {Fe(NO)2}10 DNIC 4 or dimeric {Fe(NO)2}10–{Fe(NO)2}10 DNIC 5 was also demonstrated upon reduction of the {Fe(NO)2}9 DNICs [cation][(NO)2Fe(SC6H4‐o‐NH2)2] (6) {cation = K‐18‐crown‐6‐ether (6a), [PPh4] (6b)}. In contrast to the formation of thiolate‐containing {Fe(NO)2}9 DNICs through nucleophilic cleavage of the bridging thiolates of Roussin's red esters, the transformation of complexes 4 and 5 into complexes 6a and 6b, respectively, in the presence of disulfide provides a new synthetic pathway for the synthesis of thiolate‐containing {Fe(NO)2}9 DNICs.