bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling deformation induced by seasonal variations of continental water in the Himalaya region: Sensitivity to Earth elastic structure
Authors: Chanard K. , Avouac J. P. , Ramillien G. , Genrich J.
Published: April 2014

Strong seasonal variations of horizontal and vertical positions are observed on GPS time series from stations located in Nepal, India, and Tibet (China). We show that this geodetic deformation can be explained by seasonal variations of continental water storage driven by the monsoon. For this purpose, we use satellite data from the Gravity Recovery and Climate Experiment to determine the time evolution of surface loading. We compute the expected geodetic deformation assuming a perfectly elastic Earth model. We consider Green's functions, describing the surface deformation response to a point load, for an elastic homogeneous half‐space model and for a layered nonrotating spherical Earth model based on the Preliminary Reference Earth Model and a local seismic velocity model. The amplitude and phase of the seasonal variation of the vertical and horizontal geodetic positions can be jointly adjusted only with the layered Earth model, while an elastic half‐space model fails, emphasizing the importance of using a realistic Earth elastic structure to model surface displacements induced by surface loading. We demonstrate, based on a formal inversion, that the fit to the geodetic data can be improved by adjusting the layered Earth model. Therefore, the study also shows that the modeling of geodetic seasonal variations provides a way to probe the elastic structure of the Earth, even in the absence of direct measurements of surface load variations.
Relative contribution of ENSO and East Asian winter monsoon to the South China Sea SST anomalies during ENSO decaying years
Authors: Wu Renguang , Chen Wen , Wang Guihua , Hu Kaiming
Published: April 2014

Present study investigates respective contributions of El Niño‐Southern Oscillation (ENSO) and East Asian winter monsoon (EAWM) to two periods of sea surface temperature (SST) anomalies in the South China Sea (SCS), one subsequent to the ENSO mature phase and the other in the following summer, during 1982–2010. It is found that the SST anomalies in the first period are related to the EAWM and the ENSO impact independent of EAWM is weak, which differs from previous studies. The SST anomalies in the second period are mainly due to the ENSO effect. A heat budget analysis shows that changes in shortwave radiation and wind‐related surface latent heat flux as well as horizontal advections are the processes leading to the EAWM‐related SST anomalies in the first period. The ENSO‐related SST anomalies in the second period are contributed by shortwave radiation and latent heat flux anomalies as well as meridional advection and vertical upwelling processes near the southeast coast of Indochina Peninsula. The ENSO contribution to the SCS SST anomalies in the first period is larger before than after the late 1970s. This is attributed to an earlier development of ENSO events that is followed by larger equatorial central and eastern Pacific SST anomalies in boreal summer and, subsequently, larger North Indian Ocean SST anomalies around October. Consequently, anomalous surface anticyclone over the SCS is stronger, leading to larger surface heat flux anomalies and thus a larger SST increase around October before than after the late 1970s.
Statistical characterization of atmospheric gravity waves by seismoacoustic observations
Authors: Hedlin Michael A. H. , Drob Douglas P.
Published: April 2014

We examine acoustic‐to‐seismic coupled signals from ground‐truthed explosions in northern Utah that were observed by dense seismic networks. We simulate the observed signals using both classical ray theory and the parabolic equation method in order to better understand the influence of multiscale atmospheric structures on these signals. Atmospheric models correctly predict acoustic arrival times downwind of the source, but signals are commonly observed over a much larger area than predicted using baseline models including well within the shadow zones near the source. In order to properly explain the extent of the observed infrasound wavefield in range and azimuth, the results indicate that it is necessary to account for unresolved subgrid‐scale atmosphere structures. The results also clearly show the need to account for these structures in order to properly explain the observed wave signal duration. Without accounting for small‐scale atmospheric structure, the infrasound signals are predicted to last 5–10 s but are observed to last 30–80 s. Furthermore, the amplitudes of the coupled signals relative to background noise vary steadily with distance in a manner that matches the computed predictions. The results show that infrasound signals retain much information about the large‐ and small‐scale structures in the atmosphere through which they propagate suggesting that routine observations from dense regional seismic networks might also provide a novel means of atmospheric sounding.
Concentric gravity waves in polar mesospheric clouds from the Cloud Imaging and Particle Size experiment
Authors: Yue Jia , Thurairajah Brentha , Hoffmann Lars , Alexander Joan , Chandran Amal , Taylor Michael J. , Russell James M. , Randall Cora E. , Bailey Scott M.
Published: April 2014

Five concentric atmospheric gravity wave (AGW) events have been identified in Polar Mesospheric Cloud (PMC) images of the summer mesopause region (~82–84 km) made by the Cloud Imaging and Particle Size (CIPS) instrument on board the Aeronomy of Ice in the Mesosphere satellite during the Northern Hemisphere 2007 and 2009 PMC seasons. The AGWs modulate the PMC albedo, ice water content, and particle size, creating concentric ring patterns. On only one occasion (13 July 2007), the concentric AGWs in PMCs were aligned with AGWs with similar shapes observed in 4.3 µm radiance in the lower stratosphere, as measured by Atmospheric Infrared Sounder (AIRS). Coincident AIRS and Infrared Atmospheric Sounding Interferometer nadir measurements of 8.1 µm radiance reveal a region of deep convection in the troposphere close to the estimated centers of the AGWs in the stratosphere, strongly suggesting that convection is the wave source. The AGWs in CIPS on 13 July 2007 were ~1000 km away from the observed deep convection. Three other concentric AGWs in PMCs were 500–1000 km away from deep convection in the troposphere, while no convection was observed related to the wave on 29 July 2009. We perform a 2‐D ray tracing study for the AGW event on 13 July 2007. The calculated propagation distance is much shorter than the distance between the AGWs in PMCs and the observed convection. The 2‐D ray tracing study indicates that the AGWs in PMCs and in the stratosphere are probably excited by different tropospheric convective systems.
Glyoxal observations in the global marine boundary layer
Authors: Mahajan Anoop S. , Prados‐Roman Cristina , Hay Timothy D. , Lampel Johannes , Pöhler Denis , Groβmann Katja , Tschritter Jens , Frieß Udo , Platt Ulrich , Johnston Paul , Kreher Karin , Wittrock Folkard , Burrows John P. , Plane John M.C. , Saiz‐Lopez Alfonso
Published: April 2014

Glyoxal is an important intermediate species formed by the oxidation of common biogenic and anthropogenic volatile organic compounds such as isoprene, toluene, and acetylene. Although glyoxal has been shown to play an important role in urban and forested environments, its role in the open ocean environment is still not well understood, with only a few observations showing evidence for its presence in the open ocean marine boundary layer (MBL). In this study, we report observations of glyoxal from 10 field campaigns in different parts of the world's oceans. These observations together represent the largest database of glyoxal in the MBL. The measurements are made with similar instruments that have been used in the past, although the open ocean values reported here, average of about 25 parts per trillion by volume (pptv) with an upper limit of 40 pptv, are much lower than previously reported observations that were consistently higher than 40 pptv and had an upper limit of 140 pptv, highlighting the uncertainties in the differential optical absorption spectroscopy method for the retrieval of glyoxal. Despite retrieval uncertainties, the results reported in this work support previous suggestions that the currently known sources of glyoxal are insufficient to explain the average MBL concentrations. This suggests that there is an additional missing source, more than a magnitude larger than currently known sources, which is necessary to account for the observed atmospheric levels of glyoxal. Therefore, it could play a more important role in the MBL than previously considered.
Geomagnetic field excursion recorded 17 ka at Tianchi Volcano, China: New40Ar/39Ar age and significance
Authors: Singer Brad S. , Jicha Brian R. , He Huaiyu , Zhu Rixiang
Published: April 2014

New40Ar/39Ar dating of a comenditic lava atop Tianchi Volcano, China, indicates eruption at 17.1 ± 0.9 ka. The flow interior records a pair of transitional virtual geomagnetic poles and a low paleointensity of ~25 μT. Thus, it records a geomagnetic field excursion that is younger than the 41 ka Laschamp or 32 ka Auckland excursions. Implications are: (1) following a repose of several tens of kyr, Tianchi Volcano became highly active immediately following termination of the last glaciation maximum. The flare‐up of silicic eruptions may reflect rapid deglaciation of the edifice. (2) A 17 ka age for the Tianchi excursion provides the first direct radioisotopic evidence that excursional behavior, which is imprecisely dated and less well documented magnetically at several other sites, is a global feature of geodynamo behavior. (3) During the Brunhes chron, 13 well‐dated excursions cluster into two periods, including seven between 17 and 212 ka, and six between about 530 and 730 ka.
The Boso slow slip events in 2007 and 2011 as a driving process for the accompanying earthquake swarm
Authors: Hirose Hitoshi , Matsuzawa Takanori , Kimura Takeshi , Kimura Hisanori
Published: April 2014

Near the Boso Peninsula, central Japan, slow slip events (SSEs) accompanied by earthquake swarms repeatedly occur every 4 to 7 years. We apply a Network Inversion Filter to tilt change and Global Navigation Satellite Systems displacement data simultaneously in order to obtain the spatiotemporal slip evolution of the Boso Peninsula SSEs in 2007 and 2011. Slip initiates on the eastern offshore area in both of the events and propagates to the northwestward in 2007, whereas the 2011 slip propagates to the west. These slip propagations correlate well both spatially and temporally with the migration of the accompanying seismicity. This indicates that the Boso slow slip is a major driving process for earthquake swarm activities, and that monitoring of interplate slip has the potential to be used in assessing the possibility of an earthquake in near real time.
The importance of monopole antennas for dust observations: Why Wind/WAVES does not detect nanodust
Authors: Meyer‐Vernet N. , Moncuquet M. , Issautier K. , Lecacheux A.
Published: April 2014

The charge released by impact ionization of fast dust grains impinging on spacecraft is at the basis of a well‐known technique for dust detection by wave instruments. Since most of the impact charges are recollected by the spacecraft, monopole antennas generally detect a much greater signal than dipoles. This is illustrated by comparing dust signals in monopole and dipole modes on different spacecraft and environments. It explains the weak sensitivity of Wind/WAVES dipole antennas for dust detection, so that it is not surprising that this instrument did not detect the interplanetary nanodust discovered by STEREO/WAVES. We propose an interpretation of the Wind dust data, elsewhere discussed by Malaspina et al. (2014), which explains the observed pulse amplitude and polarity for interstellar dust impacts, as well as the nondetection of nanodust. This proposed mechanism might be the dominant dust detection mechanism by some wave instruments using dipole antennas.
Very low frequency subionospheric remote sensing of thunderstorm‐driven acoustic waves in the lower ionosphere
Authors: Marshall R. A. , Snively J. B.
Published: April 2014

We present observations of narrowband subionospheric VLF transmitter signals on 20 March 2001, exhibiting coherent fluctuations of over 1 dB peak to peak. Spectral analysis shows that the fluctuations have periods of 1–4min and are largely coherent. The subionospheric propagation path of the signal from Puerto Rico to Colorado passes over two regions of convective and lightning activity, as observed by GOES satellite imagery and National Lightning Detection Network lightning data. We suggest that these fluctuations are evidence of acoustic waves launched by the convective activity below, observed in the 80–90 km altitude range to which nighttime VLF subionospheric remote sensing is sensitive. These observations show that VLF subionospheric remote sensing may provide a unique, 24h remote sensing technique for acoustic and gravity wave activity. We reproduce this event in simulations using a fluid model of gravity and acoustic wave propagation to calculate the ionospheric disturbance, followed by an electromagnetic propagation model to calculate the perturbation amplitude at the location of the VLF receiver. Simulation results show that a very large and coherent convective source is required to produce these amplitude perturbations.
Ultrathin Flexible Graphene Film: An Excellent Thermal Conducting Material with Efficient EMI Shielding
Authors: Shen Bin , Zhai Wentao , Zheng Wenge
Published: April 2014

As the portable device hardware has been increasing at a noticeable rate, ultrathin thermal conducting materials (TCMs) with the combination of high thermal conductivity and excellent electromagnetic interface (EMI) shielding performance, which are used to efficiently dissipate heat and minimize EMI problems generated from electronic components (such as high speed processors), are urgently needed. In this work, graphene oxide (GO) films are fabricated by direct evaporation of GO suspension under mild heating, and ultrathin graphite‐like graphene films are produced by graphitizing GO films. Further investigation demonstrates that the resulting graphene film with only ≈8.4 μm in thickness not only possesses excellent EMI shielding effectiveness of ≈20 dB and high in‐plane thermal conductivity of ≈1100 W m‐1 K‐1, but also shows excellent mechanical flexibility and structure integrity during bending, indicating that the graphitization of GO film could be considered as a new alternative way to produce excellent TCMs with efficient EMI shielding.
Three‐Dimensional Programmable Assembly by Untethered Magnetic Robotic Micro‐Grippers
Authors: Diller Eric , Sitti Metin
Published: April 2014

Mobile sub‐millimeter micro‐robots have demonstrated untethered motion and transport of cargo in remote, confined or enclosed environments. However, limited by simple design and actuation, they lack remotely‐actuated on‐board mechanisms required to perform complex tasks such as object assembly. A flexible patterned magnetic material which allows internal actuation, resulting in a mobile micro‐gripper which is driven and actuated by magnetic fields, is introduced here. By remotely controlling the magnetization direction of each micro‐gripper arm, a gripping motion which can be combined with locomotion for precise transport, orientation, and programmable three‐dimensional assembly of micro‐parts in remote environments is demonstrated. This allows the creation of out‐of‐plane 3D structures and mechanisms made from several building blocks. Using multiple magnetic materials in each micro‐gripper, the addressable actuation of gripper teams for parallel, distributed operation is also demonstrated. These mobile micro‐grippers can potentially be applied to 3D assembly of heterogeneous meta‐materials, construction of medical devices inside the human body, the study of biological systems in micro‐fluidic channels, 3D micro‐device prototyping or desktop micro‐factories.
Removal of Cr6+ Ions by Cross‐Linked Cassava Xanthate from Aqueous Solution
Authors: Shi Jinheng , Luo Hongsheng , Hu Jiwen , Xiao Dingshu , TU Yuanyuan , Lin Baofeng , Liang Xingquan
Published: April 2014

The cross‐linked cassava xanthate (CCX) was synthesized and used to remove Cr6+ ions from aqueous solution. The influence of multiple factors on the sorption process, including pH, temperature, contact time, sulfur content, and sorbent/sorbate ratio, was quantitatively investigated. The sorption capacity of the CCX was confirmed under different conditions. The adsorption equilibrium was fitted to Langmuir and Freundlich isotherms. The Cr‐containing cross‐linked cassava xanthate (CCX‐Cr) could be cyclically regenerated by HNO3 solution. The pyrolysis of the CCX and CCX‐Cr was measured using Fourier transform infrared spectroscopy and thermo‐gravimetric/differential thermal analysis coupling method. The CCX had higher percentage of the residues than the CCX‐Cr due to the ion exchange mechanism in the adsorption process.
Hypergonadotropic hypogonadism and hypersegmented neutrophils in a patient with ataxia‐telangiectasia‐like disorder: Potential diagnostic clues?
Authors: Yoshida Takeshi , Awaya Tomonari , Shibata Minoru , Kato Takeo , Numabe Hironao , Kobayashi Junya , Komatsu Kenshi , Heike Toshio
Published: April 2014

Ataxia‐telangiectasia‐like disorder (ATLD) is a rare autosomal recessive disorder, and has symptoms similar to ataxia‐telangiectasia (AT). ATLD is caused by mutations in the MRE11 gene, involved in DNA double‐strand break repair (DSBR). In contrast to AT, ATLD patients lack key clinical features, such as telangiectasia or immunodeficiency, and are therefore difficult to be diagnosed. We report a female ATLD patient presenting with hypergonadotropic hypogonadism and hypersegmented neutrophils, previously undescribed features in this disorder, and potential diagnostic clues to differentiate ATLD from other conditions. The patient showed slowly progressive cerebellar ataxia from 2 years of age, and MRI revealed atrophy of the cerebellum, oculomotor apraxia, mild cognitive impairment, writing dystonia, hypergonadotropic hypogonadism with primary amenorrhea, and hypersegmented neutrophils. Western blot assay demonstrated total loss of MRE11 and reduction of ATM‐dependent phosphorylation; thus, we diagnosed ATLD. Genetically, a novel missense mutation (c.140C>T) was detected in the MRE11 gene, but no other mutation was found in the patient. Our presenting patient suggests that impaired DSBR may be associated with hypergonadotropic hypogonadism and neutrophil hypersegmentation. In conclusion, when assessing patients with ataxia of unknown cause, ATLD should be considered, and the gonadal state and peripheral blood smear samples evaluated. © 2014 Wiley Periodicals, Inc.
Adsorption of Hg(II) in aqueous solutions using mercapto‐functionalized alkali lignin
Authors: Zhou Yan , Zhang Jianping , Luo Xuegang , Lin Xiaoyan
Published: April 2014

A novel adsorbent for Hg(II), mercapto‐functionalized alkali lignin (AL‐SH) was synthesized by Friedel–Crafts alkylation reaction and nucleophilic substitution reactions. The adsorbent was characterized by the techniques of Fourier transform‐infrared spectroscopy (FT‐IR), elementary analysis and thermogravimetric analysis, and N2 adsorption techniques. The effect of various parameters on Hg(II) adsorption process such as initial pH, contact time, ionic strength, initial Hg(II) concentration, temperature, and adsorbent dosage were investigated in detail through batch static experiments. The results indicated that the adsorption process of Hg(II) on AL‐SH was mainly dependent on the pH and the optimal pH value was at pH ranging from 4.0 to 6.0. The adsorption process was found to follow pseudosecond‐order kinetics and the main process was chemical adsorption, which equilibrated at 8 h. The adsorption isotherm was better described by Langmuir and Temkin isotherm equations compared to Freundlich isotherm equation and the maximum adsorption capacity obtained was 101.2 mg g−1 (pH = 4.0, 20°C, initial Hg(II) concentration was 200 mg L−1). The thermodynamic parameters of
and
were positive while
was negative, revealed that the adsorption of Hg(II) onto AL‐SH was a spontaneous and endothermic process with increased entropy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40749.
Thermal degradation kinetics, mechanical, and flame retardant properties of epoxy‐HDPE fabric‐clay composite laminates
Authors: Niranjana Prabhu T. , Demappa T.
Published: April 2014

Addition of particulates into laminates has been found to influence thermal and mechanical properties. Composite laminates of epoxy‐high density polyethylene (HDPE) fabric‐clay were prepared by reinforcing clay in the range of 0.1–0.7 phr into epoxy‐HDPE fabric laminates. These laminates are characterized for their mechanical, thermal, and flame retardant performances. With the addition of clay, an increase was found in impact resistance, tensile strength, flexural strength, and Young's modulus to an extent of 0.2 phr clay, after which there is a decrease in these properties. The thermal stability is found to decrease with the addition of clay. The improved mechanical properties are obtained at the slight expense of thermal stability. UL‐94 tests indicate a reduction in the burning rate. Morphology of the broken samples indicate better dispersion at lower clay load and tactoid formation at higher clay loading. These materials have potential applications in agriculture, construction, and decorative purposes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40751.
The influence of viscoelastic property measurements on the predicted rolling resistance of belt conveyors
Authors: O'Shea Jayne I. , Wheeler Craig A. , Munzenberger Paul J. , Ausling Daniel G.
Published: April 2014

This article discusses how determining the viscoelastic properties of the cover material of a conveyor belt, using different rheological test modes, can result in significant differences in properties for the same material and testing conditions. The viscoelastic properties are applied to two mathematical models used to predict and compare the indentation rolling resistance performance of two rubber compounds. This article demonstrates how inaccuracies in the testing of the viscoelastic properties could result in a material with higher indentation rolling resistance properties being selected for a conveying system, making the power consumption of the system larger than necessary. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40755.
Design, Synthesis and Anticancer Activity Evaluation of Some Novel Pyrrolo[1,2‐a]azepine Derivatives
Authors: Belal Amany
Published: April 2014

A novel series of pyrrolo[1,2‐a]azepine derivatives 3–7 were synthesized and their structures were confirmed by spectral and elemental analyses. Antitumor activity evaluation of these compounds was carried out against liver (HepG2), breast (MCF7), and colon (HCT116) cancer cell lines using the sulforhodamine‐B (SRB) assay method and doxorubicin as reference standard. Compounds 3 and 6 were found to be more potent than doxorubicin against HepG2 cells, with IC50 values of 4, 1.6 and 10.8 nM, respectively. Moreover, compounds 3 and 7 showed broad‐spectrum anticancer activity against all the tested cell lines, and their IC50 values were in the nanomolar range (4–44.2 nM and 20.7–45.4 nM, respectively). The 2‐benzoylamino derivative of pyrrolo[1,2‐a]azepine 5b was the most potent one against MCF7 cells (IC50 of 10.7 nM); however, the 2‐(2‐chloro‐acetylamino)‐pyrroloazepine derivative 6 was the most potent against the HCT116 cell line, with an IC50 value of 21.1 nM. The novel compounds were docked into the active site of cyclin‐dependent kinase 2 (CDK2) to explore the ability of these compounds to interact with these kinases. All compounds showed a lower binding score energy than the reference ligand.
The Structural Robustness of the Induction Motor Stator Currents Subsystem
Authors: Amezquita‐Brooks Luis , Liceaga‐Castro Eduardo , Liceaga‐Castro Jesús
Published: April 2014

Stator‐currents control is essential for several high‐performance induction motor control schemes such as field oriented control. There are numerous reports dealing with sophisticated control schemes for this subsystem. However, classical linear controllers remain widely used due to their experimental success and simplicity. Considering that the induction motor stator currents subsystem is normally represented by a fifth order non‐linear multivariable model, it is remarkable that simple fixed linear controllers, such as typical proportional integral schemes, are able to provide adequate robustness and performance in practice. In fact, it is normally assumed that this subsystem is “easy” to control, and the difficulties are mostly technical. Moreover, it is common practice to consider a stable first order linear single input single output (SISO) system as a design model. On the other hand, it is widely known that stable and minimum phase uncertain SISO systems are also “easy” to control. In this article it is formally demonstrated that the stator currents subsystem of the induction motor is the multivariable equivalent of such SISO systems. That is, it is formally demonstrated that this process is “easy” to control. This result may assist with better induction motor control and may serve as an example of the evaluation of similar multivariable systems. Real time experimental results are included.
In vitro ketamine CYP3A‐mediated metabolism study using mammalian liver S9 fractions, cDNA expressed enzymes and liquid chromatography tandem mass spectrometry
Authors: Santamaria Raphaël , Pailleux Floriane , Beaudry Francis
Published: April 2014

Ketamine is widely used in medicine in combination with several benzodiazepines, including midazolam. The objectives of this study were to develop a novel HPLC‐MS/selected reaction monitoring (SRM) method capable of quantifying ketamine and norketamine using an isotopic dilution strategy in biological matrices and study the formation of norketamine, the principal metabolite of ketamine with and without the presence of midazolam, a well‐known CYP3A substrate. The chromatographic separation was achieved using a Thermo Betasil Phenyl 100 × 2 mm column combined with an isocratic mobile phase composed of acetonitrile, methanol, water and formic acid (60:20:20:0.4) at a flow rate of 300 μL/min. The mass spectrometer was operating in selected reaction monitoring mode and the analytical range was set at 0.05–50 μm. The precision (CV) and accuracy (NOM) observed were 3.9–7.8 and 95.9–111.1% respectively. The initial rate of formation of norketamine was determined using various ketamine concentrations and Km values of 18.4, 13.8 and 30.8 μm for rat, dog and human liver S9 fractions were observed, respectively. The metabolic stability of ketamine on liver S9 fractions was significantly higher in human (T1/2 = 159.4 min) compared with rat (T1/2 = 12.6 min) and dog (T1/2 = 7.3 min) liver S9 fractions. Moreover significantly lower IC50 and Ki values observed in human compared with rat and dog liver S9 fractions. Experiments with cDNA expressed CYP3A enzymes showed that the formation of norketamine is mediated by CYP3A but results suggest an important contribution from other isoenzymes, most likely CYP2C particularly in rat. Copyright © 2014 John Wiley & Sons, Ltd.
Biosorption of Toxic Heavy Metals on Sawdust
Authors: Mishra Vishal , Tadepalli Srinivas
Published: April 2014

The present investigation deals with the biosorption of Zn2+, Cr3+, and Pb2+ in the liquid phase on the surface of zinc sequestering bacterium VMSDCM (accession no. HQ108109) cells immobilized on pineapple peel powder particles (the term sawdust has been used for immobilized microorganisms). In batch studies, the biosorption data design and regression model for predicting the relationship between the metal ion and their biosorption capacity used were Minimum Run Res V Design and quantitative ion character activity relationship (QICAR), respectively. The values of qmax calculated by the Langmuir isotherm were found to be in increasing order of Cr3+ < Zn2+ < Pb2+. The results of the present investigation showed that the pH and contact time played an important role in the removal of Zn2+ from the liquid phase. In case of Cr3+, the significant independent parameters associated with metal ion removal were the initial concentration of the metal ion and the pH. The important independent parameters for Pb2+ removal were the temperature (°C) and pH, respectively. In QICAR modeling, among all six physico‐chemical characteristics only the ionization potential (eV) played a negative role in the biosorption of metal ions. The rationale behind the inverse relationship between the removal of metal ions and eV was the variation of the corresponding covalent index. The rest of the remaining five physico‐chemical properties showed that regression models fitted quite well and were characterized by high values of the linear regression coefficient (R2), adjusted R2, and low values of the error function (χ2). In the present work, it was concluded that the immobilized cells of sawdust can be a suitable alternative for the removal of heavy metal ions from the liquid phase. The initial concentration of all the metals was kept at 50 mg L−1 each in the liquid phase. The residual concentrations of Zn2+, Cr3+, and Pb2+ after the biosorption were 0.4, 1.2, and 0.2 mg L−1, respectively.
Molecular magnetic resonance probe targeting VEGF165: preparation and in vitro and in vivo evaluation
Authors: You Xiao‐Guang , Tu Rong , Peng Ming‐Li , Bai Yu‐Jie , Tan Mingqian , Li Han‐Jian , Guan Jing , Wen Li‐Jun
Published: April 2014

A new method for imaging the tumor human vascular endothelial growth factor 165 (VEGF 165) is presented. A magnetic resonance imaging (MRI) probe was prepared by crosslinking ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles to the aptamer for tumor vascular endothelial growth factor 165 (VEGF165‐aptamer). The molecular probe was evaluated for its in vitro and in vivo activities toward VEGF165. Enzyme‐linked immunosorbent assay showed that the VEGF165‐aptamer–USPIO nanoparticles conjugate specifically binds to VEGF165 in vitro. A cell proliferation test showed that VEGF165‐aptamer–USPIO seems to block the proliferation of human umbilical vein endothelial cells induced by free VEGF165, suggesting that VEGF165 is an effective target of this molecular probe. In xenograft mice carrying liver cancer that expresses VEGF165, T2‐weighted imaging of the tumor displayed marked negative enhancement 3 h after the intravenous administration of VEGF165‐aptamer–USPIO. The enhancement disappeared 6 h after administration of the probe. These results suggest the targeted imaging effect of VEGF165‐aptamer–USPIO probe in vivo for VEGF165‐expressing tumors. This is the first report of a targeted MRI molecular probe based on USPIO and VEGF165‐aptamer. Copyright © 2014 John Wiley & Sons, Ltd.
Perioperative chemotherapy for muscle‐invasive bladder cancer: A population‐based outcomes study
Authors: Booth Christopher M. , Siemens D. Robert , Li Gavin , Peng Yingwei , Tannock Ian F. , Kong Weidong , Berman David M. , Mackillop William J.
Published: April 2014

BACKGROUND

Practice guidelines recommend neoadjuvant chemotherapy (NACT) for bladder cancer. However, the evidence in support of adjuvant chemotherapy (ACT) is less robust. Here we describe whether the evidence of efficacy for NACT/ACT was sufficient to change clinical practice and whether the efficacy demonstrated in clinical trials was translated into effectiveness in the general population.

METHODS

Electronic records of treatment were linked to the population‐based Ontario Cancer Registry to identify all patients with bladder cancer treated with cystectomy in Ontario 1994‐2008. Utilization of NACT/ACT was compared across 1994‐1998, 1999‐2003, and 2004‐2008. Logistic regression was used to analyze factors associated with NACT/ACT. Cox model and propensity score analyses were used to explore the association between ACT and survival.

RESULTS

Two thousand forty‐four patients underwent cystectomy for muscle‐invasive bladder cancer (MIBC). Use of NACT remained stable (mean, 4%), whereas utilization of ACT increased over time (16%, 18%, 22%; P = .001). Advanced stage (T3/T4; OR, 1.83; 95% CI, 1.38‐2.46) and node‐positive disease (OR, 8.10; 95% CI, 6.20‐10.7) were associated with greater utilization of ACT. Five‐year overall survival (OS) and cancer‐specific survival (CSS) for all patients was 29% (95% CI, 28%‐31%) and 33% (95% CI, 31%‐35%), respectively. Utilization of ACT was associated with improved OS (HR, 0.71; 95% CI, 0.62‐0.81) and CSS (HR, 0.73; 95% CI, 0.64‐0.84). Results were consistent in propensity score analyses.

CONCLUSIONS

NACT remains substantially underutilized in routine clinical practice. Our results suggest that perioperative chemotherapy is associated with a substantial survival benefit in the general population. Patients who are planning to undergo cystectomy for bladder cancer should be reviewed by a multidisciplinary team. Cancer 2014;120:1630–1638. © 2013 American Cancer Society.
Analysis of flow changes in side branches jailed by flow diverters in rabbit models
Authors: Cebral Juan R. , Raschi Marcelo , Mut Fernando , Ding Yong‐Hond , Dai Daying , Kadirvel Ramanathan , Kallmes David
Published: April 2014

Understanding the flow alteration in side branches during flow diversion treatment of cerebral aneurysms is important to prevent ischemic complications and improve device designs. Flow diverters were placed in the aorta of four rabbits crossing the origin of side arteries. Subject‐specific computational models were constructed from 3D angiographies and Doppler ultrasounds (DUSs). Flow simulations were run before and after virtually deploying the flow diverters, assuming distal resistances remained unchanged after treatment. All jailed arteries remained patent angiographically 8 weeks after treatment. The computational models estimated decreases compared to pretreatment in the mean flow rates between 2% and 20% and in peak flow rates between 5% and 36%. The major changes were observed during systole. Flow patterns did not exhibit recirculation zones before treatment. Implantation of the flow diverters altered the flow structure only locally near the device wires. No major recirculation regions were created or destroyed. Flow diverters seem safe with respect to perforator or side branch occlusion. Relatively small changes in flow rates through jailed arteries are expected, even for moderate to large degrees of coverage of their origins. These results seem consistent with previous clinical experiences where no or very few complications related to perforator occlusion have been reported.Copyright © 2014 John Wiley & Sons, Ltd.
Automated detection of circulating tumor cells with naive Bayesian classifiers
Authors: Svensson Carl‐Magnus , Krusekopf Solveigh , Lücke Jörg , Thilo Figge Marc
Published: April 2014

Personalized medicine is a modern healthcare approach where information on each person's unique clinical constitution is exploited to realize early disease intervention based on more informed medical decisions. The application of diagnostic tools in combination with measurement evaluation that can be performed in a reliable and automated fashion plays a key role in this context. As the progression of various cancer diseases and the effectiveness of their treatments are related to a varying number of tumor cells that circulate in blood, the determination of their extremely low numbers by liquid biopsy is a decisive prognostic marker. To detect and enumerate circulating tumor cells (CTCs) in a reliable and automated fashion, we apply methods from machine learning using a naive Bayesian classifier (NBC) based on a probabilistic generative mixture model. Cells are collected with a functionalized medical wire and are stained for fluorescence microscopy so that their color signature can be used for classification through the construction of Red‐Green‐Blue (RGB) color histograms. Exploiting the information on the fluorescence signature of CTCs by the NBC does not only allow going beyond previous approaches but also provides a method of unsupervised learning that is required for unlabeled training data. A quantitative comparison with a state‐of‐the‐art support vector machine, which requires labeled data, demonstrates the competitiveness of the NBC method. © 2014 International Society for Advancement of Cytometry
Precipitation event distribution in Central Argentina: spatial and temporal patterns
Authors: Magliano Patricio N. , Fernández Roberto J. , Mercau Jorge L. , Jobbágy Esteban G.
Published: April 2014

The annual amount of precipitation inputs received by a site during a full year is considered a dominant spatial and temporal control of primary productivity and other related process in arid to subhumid ecosystems. However, to be effectively used by plants, these inputs have to escape runoff, favoured by large and less frequent precipitation events, and evaporation losses, favoured by small and more frequent events. Thus, available water for plant transpiration is not only influenced by the annual sum of precipitation events but also by their frequency‐size distribution. In this paper, we characterize this distribution and its association to total annual precipitation inputs through space (five sites along a tenfold precipitation gradient across 1000 km) and time (1961–2010) in the plains of central Argentina. We decomposed total precipitation into two structural components, which are the frequency and mean size of events, showing that they have similar contributions (log–log slopes ≈ 0·5) explaining precipitation shifts in space. Over time, however, we found a preponderance of mean event size explaining precipitation fluctuations, particularly towards wetter sites (log–log slopes increasing from 0·61 to 0·88). The relative variability of event sizes, independent of their mean size (i.e. inequality), was numerically characterized with Gini coefficients derived from Lorenz curves, which showed highly constant values in space and time. Assuming fixed event‐size thresholds for evaporation and runoff, and ignoring other controls beyond precipitation structure, the proportion of water potentially available for plant transpiration grew with total precipitation, raising from 0·45 to 0·71 from the driest to the wettest sites, but displaying stronger responses to total precipitation in time, particularly in drier sites. No long‐term trends in any of the precipitation structure variables were detected. Response functions of frequency and mean size of events to annual precipitation together with Lorenz curves appeared to be robust descriptors of precipitation regimes that, not requiring any a priori assumptions, are useful to assess how spatial and temporal shifts in total precipitation may concurrently affect its relative availability for plant transpiration. Copyright © 2014 John Wiley & Sons, Ltd.
Stereocontrolled Synthesis of a C1–C10 Building Block (“Southwestern Moiety”) for the Unnatural Enantiomers of the Polyene Polyol Antibiotics Filipin III and Pentamycin: A Sultone‐Forming Ring‐Closing Metathesis for Protection of Homoallylic Alcohols
Authors: Walleser Patrick , Brückner Reinhard
Published: April 2014

In C2‐symmetric diol 10 one OH group was substituted by crotonic acid and the other was incorporated in an ethenesulfonate. A twofold ring‐closing metathesis under forcing conditions provided unsaturated lactone/unsaturated sultone 24. Conjugate addition of Li2(PhMe2Si)2Cu(CN) to both C=C bonds was followed by opening of the sultone moiety with Bu4N+F–. Resultant homoallylic alcohol 28 was carried on to acetonide‐containing lactone 31. Its CpTiCl2 enolate underwent a completely diastereoselective aldol addition to hexanal. Functional group interconversions rendered “southwestern” C1–C10 building block 37. The steps (1) ethenesulfonylation of a homoallylic alcohol, (2) sultone formation, (3) Li2(PhMe2Si)2Cu(CN) addition, and (4) alcohol release by fluoride‐induced fragmentation, from our main sequence represent a new protection/deprotection stragegy for a secondary homoallylic alcohol, as demonstrated with a model compound, too.
Synthesis of Pyranonucleoside‐6′‐triphosphates through the cycloSal‐Method
Authors: Huchting Johanna , Meier Chris
Published: April 2014

The high yielding synthesis of pyranonucleoside‐6′‐triphosphates by using the cycloSal‐method is described. Synthesis of the activated cycloSal‐pyranonucleoside‐6′‐phosphate triesters was achieved by applying a synthetic route that had been developed for the synthesis of cycloSal‐(glycopyranosyl‐6)‐phosphates by us. The route involved regioselective 6′‐tert‐butyldimethylsilyl protection and exchange of the silyl protecting group by the fluorenylmethyloxycarbonyl (Fmoc) group. The 6′‐Fmoc‐protected derivatives were selectively converted into the cycloSal‐triester. These were then very efficiently converted into triphosphates by a “titration‐like” reaction with pyrophosphate. Simple purification by first ion exchange followed by reversed phase (RP) column chromatography afforded the triphosphates in very good yields.
Effects of copper exposure on hatching success and early larval survival in marbled salamanders, Ambystoma opacum
Authors: Soteropoulos Diana L. , Lance Stacey L. , Flynn R. Wesley , Scott David E.
Published: April 2014

The creation of wetlands, such as urban and industrial ponds, has increased in recent decades, and these wetlands often become enriched in pollutants over time. One metal contaminant trapped in created wetlands is copper (Cu2+). Copper concentrations in sediments and overlying water may affect amphibian species that breed in created wetlands. The authors analyzed the Cu concentration in dried sediments from a contaminated wetland and the levels of aqueous Cu released after flooding the sediments with different volumes of water, mimicking low, medium, and high pond-filling events. Eggs and larvae of Ambystoma opacum Gravenhorst, a salamander that lays eggs on the sediments in dry pond beds that hatch on pond-filling, were exposed to a range of Cu concentrations that bracketed potential aqueous Cu levels in created wetlands. Embryo survival varied among clutches, but increased Cu levels did not affect embryo survival. At Cu concentrations of 500 µg/L or greater, however, embryos hatched earlier, and the aquatic larvae died shortly after hatching. Because Cu concentrations in sediments increase over time in created wetlands, even relatively tolerant species such as A. opacum may be affected by Cu levels in the posthatching environment. Environ Toxicol Chem 2014;33:1631–1637. © 2014 SETAC
Partitioning of perfluorooctanesulfonate and perfluorohexanesulfonate in the aquatic environment after an accidental release of aqueous film forming foam at Schiphol Amsterdam Airport
Authors: Kwadijk Christiaan J.A.F. , Kotterman Michiel , Koelmans Albert A.
Published: April 2014

In summer 2008, an accidental release of aqueous film forming foam (AFFF) took place at Schiphol Amsterdam Airport (The Netherlands). After the release, water, fish, and sediment samples were collected and analyzed for perfluoroalkyl sulfonates (PFSAs). In situ perfluorooctane sulfonate (PFOS) sediment–water distribution factor (KD) values, bioaccumulation factor (BAF) values, and biota–sediment accumulation factor (BSAF) values showed a remarkable agreement among reference and impacted sites, 10 wk after the incident as well as after 3 yr. Environ Toxicol Chem 2014;33:1761–1765. © 2014 SETAC
Canopy conductance in a two‐storey Siberian boreal larch forest, Russia
Authors: Xue Bao‐Lin , Li Zhanling , Yin Xin‐An , Zhang Tieliang , Iida Shin'ichi , Otsuki Kyoichi , Ohta Takeshi , Guo Qinghua
Published: April 2014

A larch forest in eastern Siberia was characterized by the presence of two distinct storeys, the overstorey with a small leaf area index (LAI) and a dense understorey with a relatively large LAI. To understand the roles of the overstorey and understorey in forest–atmosphere water exchange, canopy conductance (Gc), a critical parameter used in determining the energy and mass exchange, was calculated on the basis of latent heat flux above the overstorey and understorey, measured separately. Results showed that Gc for the overstorey (Gco) and understorey (Gcu) experienced different seasonal fluctuations. Gco was smaller than Gcu during periods of leaf expansion and leaf fall and showed an increasing trend until 1 month after the onset of leaf expansion. In contrast, a sharp decrease in Gco was observed immediately before onset of leaf fall. Furthermore, Gco was slightly larger than Gcu during the fully foliated period. A simple model using solar radiation and vapour pressure deficit (D) as inputs successfully reproduced the Gc in fully foliated periods with acceptable accuracy. Furthermore, both the understorey and overstorey in this study have a large reference Gc (Gc at D = 1 KPa) than their counterparts of other boreal forests and would not be able to sustain a constant leaf–soil water potential difference as D increases. We speculated that this confers the forest with an advantage allowing it to be able to sustain carbon assimilation during large D days and thus provides for the survival of the ecosystem during the short growing season at this site. Copyright © 2014 John Wiley & Sons, Ltd.
Hydrological model uncertainty due to precipitation‐phase partitioning methods
Authors: Harder Phillip , Pomeroy John W.
Published: April 2014

Precipitation‐phase partitioning methods (PPMs) that are used in simulating cold‐region hydrological processes vary significantly. Typically, PPMs are based on empirical algorithms that are driven by readily available near‐surface air temperature but ignore the physical processes controlling precipitation phase by not incorporating humidity. Because these lack any physical basis, there is uncertainty in their spatial and temporal transferability. Recently, humidity‐based methods that have a stronger physical basis and smaller uncertainty have been developed. To quantify the uncertainty that empirical PPMs introduce into hydrological simulations, a cold‐region hydrological modelling platform was used with a physically based PPM and a selection of empirical PPMs to calculate a set of snow regime and streamflow regime indices. The empirical PPMs included a single air temperature threshold and a double air temperature threshold, whereas the physically based PPM used a psychrometric energy balance model. All calculations were run with near‐surface meteorological observations that typically drive hydrological models. Intercomparison of the hydrological responses to the PPMs highlighted substantial differences between the wide range of responses to empirical algorithms and the very small uncertainty due to physically based methods. Uncertainty of hydrological processes, quantified by simulating over a range of air temperature thresholds, reached 20% for the rainfall fraction, 0.4 mm/day for basin discharge, 160 mm of peak snow water equivalent, 36 days for hydrological uncertainty snow cover duration, 26 days for snow‐free date and 10 days for peak discharge date. The implication of this research is that the reduced uncertainty derived from implementing physically based PPMs, for operational or research purposes, are greatest for snowpack prediction in mountain basins. However for streamflow discharge calculations, the reduced uncertainty was greatest in prairie and alpine basins due to the additional effects of precipitation phase calculations on frozen soil infiltration and summer snowmelt processes respectively. Copyright © 2014 John Wiley & Sons, Ltd.