bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate‐related variations in atmospheric Sb and Tl in the EPICA Dome C ice (East Antarctica) during the past 800,000 years
Authors: Hur Soon Do , Soyol‐Erdene Tseren‐Ochir , Hwang Hee Jin , Han Changhee , Gabrielli Paolo , Barbante Carlo , Boutron Claude F. , Hong Sungmin
Published: August 2013

A record of antimony (Sb) and thallium (Tl) from the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core provides the characteristics of climate‐related natural changes in concentrations and fluxes of these toxic elements over the time period back to Marine Isotope Stage 20.2, ~800 kyr B.P. A strong variability in concentrations and fluxes are observed for both elements, with considerably higher values during glacial maxima and lower values during intermediate and warm periods. Rock and soil dust accounts for, on average, 58% of Sb and 76% of Tl in ice during glacial maxima. This contribution remains significant during warm periods, accounting for 21% for Sb and 27% for Tl. The contribution from volcanoes appears to be very important particularly for Tl when climatic conditions become warmer, with an estimated volcanic contribution of 72% for Tl during interglacials. The sea‐salt contribution is significant for Sb, particularly during intermediate climatic periods, with an average contribution of 17%. This sea‐salt contribution is most likely caused by greater production of sea salt from highly saline frost flowers and relatively more efficient transport of Sb‐enriched sea‐ice salt from source areas on the East Antarctic Plateau. Our ice core data, along with snow data recently reported from the Antarctic snow layers at Dome Fuji, shows that the present‐day Sb flux (6.6 ng/m2/yr) is approximately double the highest natural level (2.8 ng/m2/yr) during glacial maxima throughout the last successive eight glacial/interglacial cycles. This result indicates that human activity has induced the greatest perturbation of the atmospheric cycle of Sb ever experienced over a period of ~800 kyr in the most remote area on Earth.
The effects of reflected protons on the plasma environment of the moon for parallel interplanetary magnetic fields
Authors: Halekas J. S. , Poppe A. R. , McFadden J. P. , Glassmeier K.‐H.
Published: August 2013

For the unique case of magnetic field parallel to the solar wind flow, a column of reflected protons can accumulate upstream from the Moon. We investigate observations from the ARTEMIS probes for an extended period with this geometry. During this time, P2 observes strong wave turbulence in two frequency bands above and below the ion cyclotron frequency near the Moon, not seen by P1 farther from the Moon. The lower frequency oscillations prove consistent with kinetic magnetosonic waves resonantly generated by reflected protons, and test particle calculations confirm that a significant column of reflected protons lies upstream when the waves occur. The reflected protons perturb a large volume of plasma around the Moon, extending upstream as well as into the wake. The waves observed near the Moon during this time period have many similarities to those found in the terrestrial foreshock and at comets, suggesting the potential for comparative studies.
Decrease in sodium density observed during auroral particle precipitation over Tromsø, Norway
Authors: Tsuda T. T. , Nozawa S. , Kawahara T. D. , Kawabata T. , Saito N. , Wada S. , Ogawa Y. , Oyama S. , Hall C. M. , Tsutsumi M. , Ejiri M. K. , Suzuki S. , Takahashi T. , Nakamura T.
Published: August 2013

Using a simultaneous and common‐volume observation by a European incoherent scatter (EISCAT) VHF radar and a sodium lidar at Tromsø, Norway (69.6°N, 19.2°E), we have determined, for the first time, the effect of pure particle precipitation, excluding that of the electric field, on sodium density variations. Our observation on 24–25 January 2012 showed that sodium atom density decreased when there was no ion temperature enhancement (indicating a weak electric field) and the electron density increased (indicating strong particle precipitation). From the results, we have concluded that auroral particle precipitation induced sodium atom density decrease in this event. Furthermore, a discussion is provided regarding the time response of the decrease in sodium density.
The Effect of the Cathepsin K Inhibitor ONO-5334 on Trabecular and Cortical Bone in Postmenopausal Osteoporosis: The OCEAN Study
Authors: Engelke Klaus , Nagase Shinichi , Fuerst Thomas , Small Maria , Kuwayama Tomohiro , Deacon Stephen , Eastell Richard , Genant Harry K
Published: August 2013

ONO-5334 (Ono Pharmaceutical Co., Ltd., Osaka, Japan) inhibits cathepsin K and has been shown to increase areal bone mineral density (BMD) at the hip and spine in postmenopausal osteoporosis. Quantitative computed tomography (QCT) allows the study of the cortical and trabecular bone separately and provides structural information such as cortical thickness. We investigated the impact of 2 years of cathepsin K inhibition on these different bone compartments with ONO-5334. The clinical study was a randomized, double-blind, placebo, and active controlled parallel group study conducted in 13 centers in six European countries. The original study period of 12 months was extended by another 12 months. A total of 147 subjects (age 55–75 years) of the QCT substudy who participated in the extension period were included. Subjects had been randomized into one of five treatment arms: placebo; ONO-5334 50 mg twice per day (BID); ONO-5334 100 mg once daily (QD); ONO-5334 300 mg QD; or alendronate 70 mg once weekly (QW). QCT was obtained to evaluate bone structure at the lumbar spine and proximal femur. After 24 months ONO-5334 showed statistically significant increases versus placebo for integral, trabecular, and cortical BMD at the spine and the hip (for ONO-5334 300 mg QD, BMD increases were 10.5%, 7.1%, and 13.4% for integral, cortical, and trabecular BMD at the spine, respectively, and 6.2%, 3.4%, and 14.6% for integral, cortical, and trabecular total femur BMD, respectively). Changes in cortical and trabecular BMD in the spine and hip were similar for alendronate as for ONO-5334. Integral volume did not demonstrate statistically significant changes under ONO-5334 treatment, thus there was no evidence of periosteal apposition, neither at the spine nor at the femur. Cortical thickness changes were not statistically significant for ONO-5334 in the spine and hip, with exception of a 2.1% increase after month 24 in the intertrochanter for ONO-5334 300 mg QD. Over 2 years ONO-5334 showed a statistically significant and persistent increase of trabecular and integral BMD at the spine and the hip. Cortical BMD also progressively increased but at a lower rate. Changes in bone size and of periosteal apposition were not observed. © 2014 American Society for Bone and Mineral Research.
Spin‐component‐scaled double hybrids: An extensive search for the best fifth‐rung functionals blending DFT and perturbation theory
Authors: Kozuch Sebastian , Martin Jan M. L.
Published: August 2013

Following up on an earlier preliminary communication (Kozuch and Martin, Phys. Chem. Chem. Phys. 2011, 13, 20104), we report here in detail on an extensive search for the most accurate spin‐component‐scaled double hybrid functionals [of which conventional double hybrids (DHs) are a special case]. Such fifth‐rung functionals approach the performance of composite ab initio methods such as G3 theory at a fraction of their computational cost, and with analytical derivatives available. In this article, we provide a critical analysis of the variables and components that maximize the accuracy of DHs. These include the selection of the exchange and correlation functionals, the coefficients of each component [density functional theory (DFT), exact exchange, and perturbative correlation in both the same spin and opposite spin terms], and the addition of an ad‐hoc dispersion correction; we have termed these parametrizations “DSD‐DFT” (Dispersion corrected, Spin‐component scaled, Double‐hybrid DFT). Somewhat surprisingly, the quality of DSD‐DFT is only mildly dependent on the underlying DFT exchange and correlation components, with even DSD‐LDA yielding respectable performance. Simple, nonempirical GGAs appear to work best, whereas meta‐GGAs offer no advantage (with the notable exception of B95c). The best correlation components appear to be, in that order, B95c, P86, and PBEc, while essentially any good GGA exchange yields nearly identical results. On further validation with a wider variety of thermochemical, weak interaction, kinetic, and spectroscopic benchmarks, we find that the best functionals are, roughly in that order, DSD‐PBEhB95, DSD‐PBEP86, DSD‐PBEPW91, and DSD‐PBEPBE. In addition, DSD‐PBEP86 and DSD‐PBEPBE can be used without source code modifications in a wider variety of electronic structure codes. Sample job decks for several commonly used such codes are supplied as electronic Supporting Information. Copyright © 2013 Wiley Periodicals, Inc.
Thrombus in the left atrial septal pouch mimicking myxoma
Authors: Shimamoto Keiko , Kawagoe Takuji , Dai Kazuoki , Inoue Ichiro
Published: August 2013

A 15 × 13 mm mobile ovoid mass attached via a 15 × 5 mm stalk to the interatrial septum in the left atrium was detected on transesophageal echocardiography and was diagnosed as a myxoma in a 70‐year‐old woman with chronic atrial fibrillation. She was prescribed anticoagulant therapy with warfarin before elective cardiac surgery and demonstrated no thromboembolic event during a 2.5‐month period. Preoperative transesophageal echocardiography showed the disappearance of the intracardiac mass and the presence of a left atrial septal pouch, suggesting that the initial image was a thrombus originating from the left atrial septal pouch. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42:185–188, 2014
Delay discounting of monetary rewards over a wide range of amounts
Authors: Green Leonard , Myerson Joel , Oliveira Luís , Chang Seo Eun
Published: August 2013

The present study examined delay discounting of hypothetical monetary rewards over a wide range of amounts (from $20 to $10 million) in order to determine how reward amount affects the parameters of the hyperboloid discounting function and to compare fits of the hyperboloid model with fits of two discounting models used in neuroeconomics: the quasi‐hyperbolic and the double‐exponential. Of the three models assessed, the hyperboloid provided the best fit to the delay discounting data. The present delay discounting results may be compared to those of a previous study on probability discounting (Myerson, Green, & Morris, 2011) that used the same extended range of amounts. The hyperboloid function accurately described both types of discounting, but reward amount had opposite effects on the degree of discounting. Importantly, the amount of delayed reward affected the rate parameter of the hyperboloid discounting function but not its exponent, whereas the opposite was true for the amount of probabilistic reward. The finding that the exponent of the hyperboloid discounting function remains relatively constant across a wide range of delayed amounts provides strong support for a psychophysical scaling interpretation, and stands in stark contrast to the finding that the exponent of the hyperboloid function increases with the amount of probabilistic reward. Taken together, these findings argue that delay and probability discounting involve fundamentally different decision‐making mechanisms.
The effect of solar radio bursts on the GNSS radio occultation signals
Authors: Yue Xinan , Schreiner William S. , Kuo Ying‐Hwa , Zhao Biqiang , Wan Weixing , Ren Zhipeng , Liu Libo , Wei Yong , Lei Jiuhou , Solomon Stan , Rocken Christian
Published: August 2013

Solar radio burst (SRB) is the radio wave emission after a solar flare, covering a broad frequency range, originated from the Sun's atmosphere. During the SRB occurrence, some specific frequency radio wave could interfere with the Global Navigation Satellite System (GNSS) signals and therefore disturb the received signals. In this study, the low Earth orbit‐ (LEO‐) based high‐resolution GNSS radio occultation (RO) signals from multiple satellites (COSMIC, CHAMP, GRACE, SAC‐C, Metop‐A, and TerraSAR‐X) processed in University Corporation for Atmospheric Research (UCAR) were first used to evaluate the effect of SRB on the RO technique. The radio solar telescope network (RSTN) observed radio flux was used to represent SRB occurrence. An extreme case during 6 December 2006 and statistical analysis during April 2006 to September 2012 were studied. The LEO RO signals show frequent loss of lock (LOL), simultaneous decrease on L1 and L2 signal‐to‐noise ratio (SNR) globally during daytime, small‐scale perturbations of SNR, and decreased successful retrieval percentage (SRP) for both ionospheric and atmospheric occultations during SRB occurrence. A potential harmonic band interference was identified. Either decreased data volume or data quality will influence weather prediction, climate study, and space weather monitoring by using RO data during SRB time. Statistically, the SRP of ionospheric and atmospheric occultation retrieval shows ~4% and ~13% decrease, respectively, while the SNR of L1 and L2 show ~5.7% and ~11.7% decrease, respectively. A threshold value of ~1807 SFU of 1415 MHz frequency, which can result in observable GNSS SNR decrease, was derived based on our statistical analysis.
Estimating the effects of ionospheric plasma on solar wind/magnetosphere coupling via mass loading of dayside reconnection: Ion‐plasma‐sheet oxygen, plasmaspheric drainage plumes, and the plasma cloak
Authors: Borovsky Joseph E. , Denton Michael H. , Denton Richard E. , Jordanova Vania K. , Krall Jonathan
Published: August 2013

Estimates are calculated for the storm time reduction of solar wind/magnetosphere coupling by the mass density ρm of the magnetospheric plasma. Based on the application of the Cassak‐Shay reconnection‐rate formula at the dayside magnetopause, a numerical factor M is developed to quantify the effect of ρm on the dayside reconnection rate. It is argued that the mass loading of dayside reconnection by ρm also makes reconnection more susceptible to shutoff by magnetosheath velocity shear: a formula is developed to estimate the shortening of the dayside reconnection X‐line by ρm. Surveys of plasmaspheric drainage plumes at geosynchronous orbit during high‐speed‐stream‐driven storms and coronal mass ejection (CME)‐driven storms are presented: in the surveys the CME‐driven storms are separated into sheath‐driven portions and magnetic‐cloud‐driven portions. The storm time mass density of the warm plasma cloak (ionospheric outflows into the electron plasma sheet) is obtained from Alfven‐wave analysis at geosynchronous orbit. A methodology is developed to extrapolate geosynchronous‐orbit plasma measurements to the dayside magnetopause. For each of the three plasmas, estimates of the fractional reduction of the total dayside reconnection rate vary, with typical values of tens of percent; i.e., solar wind/magnetosphere coupling is reduced by tens of percent during storms by oxygen in the ion plasma sheet, by the plasmaspheric drainage plume, and by the plasma cloak. Dependence of the reduction on the F10.7 solar radio flux is anticipated. Via these ionospheric‐origin plasmas, the magnetosphere can exert some control over solar wind/magnetosphere coupling. Pathways to gain a fuller understanding of the physics of the solar wind‐driven magnetosphere‐ionosphere system are discussed.
Decadal changes of Meiyu rainfall around 1991 and its relationship with two types of ENSO
Authors: Zhu Jian , Huang Dan‐Qing , Zhang Yao‐Cun , Huang An‐Ning , Kuang Xue‐Yuan , Huang Ying
Published: August 2013

This study investigates Meiyu (June‐July) rainfall from 1980 to 2000 over Yangtze‐Huaihe River valley (YHRV) and reveals a decadal change around 1991 with a seesaw‐like distribution. This decadal change is closely associated with negative phase of preceding winter El Niño–Southern Oscillation (ENSO) Modoki (EM) in the pre‐1991 epoch and positive phase of conventional ENSO (CE) in the post‐1991 epoch. In response to negative EM (pre‐1991 epoch), the source of water vapor is western North Pacific, associated with the eastward retreat of western Pacific subtropical high (WPSH) and the northward shift of East Asian westerly jet (EAWJ). On the other hand, in response to positive CE (post‐1991 epoch), water vapor generally comes from the South China Sea, associated with the enhancement and westward advance of the WPSH and southward shift of the EAWJ. Two possible mechanisms are proposed to explain the relationship between preceding winter sea surface temperature (SST) and Meiyu rainfall over YHRV in the two epochs. In the pre‐1991 epoch, due to enhanced precipitation, solar radiation decreases, resulting in SST cooling over western North Pacific in Meiyu period. An anomalous anticyclone associated with the SST cooling suppresses precipitation over northern part of YHRV. Meanwhile, an anomalous cyclone accompanied with the anticyclone locates over East China Sea and brings more precipitation to the southern part of YHRV. In the post‐1991 epoch, the persistent simultaneous warming in eastern equatorial Pacific and Indian Ocean leads to abundant moisture brought to southern China. Further analysis suggests that the two types of ENSO have asymmetric features with respect to the impact of their positive and negative phases on the seesaw‐like Meiyu rainfall, which is closely related with EM La Niña (CE El Niño) in the pre‐1991 epoch (post‐1991 epoch).
Charge rearrangement deduced from nearby electric field measurements of an intracloud flash with K‒changes
Authors: Hager William W. , Feng Wei
Published: August 2013

An intracloud flash near Langmuir Laboratory is analyzed to determine the net rearrangement of charge. The analysis employed data from a balloon borne electric field sensor, or Esonde, that was within a few hundred meters of the lightning channel, data from a similar Esonde on a mountain about 6.4 km from the balloon, and data from the New Mexico Institute of Mining and Technology Lightning Mapping Array (LMA). The recovery of the charge transport required the solution of Poisson's equation over the mountainous terrain surrounding Langmuir Laboratory and the solution of a vastly under‒determined system of equations. The charge movement is analyzed using a new smooth charge transport model that incorporates constraints in the least squares fitting process through the use of penalty terms to smooth the charge movement and prevent data overfitting. The electric field measurements were consistent with about 26% of the negative charge being transported to the end of the channel, 36% deposited along the channel in the positive region, 8% deposited near the start of the channel in the positive region, and 30% deposited in another positive region several kilometers beneath the main channel. The transport of negative charge to a lower positive region occurred during the K‒processes when some negative charge was also deposited along the main channel in the upper positive region. Hence, the charge transport process during the K‒processes amounted to a tripolar charge rearrangement where the charge from the negative region was transported to two distinct positive regions, the positive region along the main channel and a lower positive region beneath the main channel. High altitude, widely scattered LMA sources beyond the end of the main channel could indicate the existence of streamers which transported the end‒of‒channel charge into the surrounding volume. Although the LMA showed the development of two upper channels, the charge transport analysis showed that measurable charge transport only occurred on one of the channels. The channel that did not transport charge was missing the high altitude, widely scattered LMA sources seen at the end of the channel that carried charge.
Synthesis and Antitumor Activity of New Polysubstituted Thiophenes and 1,3,4‐Thiadiazoles Incorporating 2,6‐Pyridine Moieties
Authors: Ali Korany A. , Abdalghfar Heba S. , Mahmoud Khaled , Ragab Eman A.
Published: August 2013

The versatile multifunctional unreported pyridine‐2,6‐bis(2‐cyano‐N‐phenyl‐3‐oxopropanethioamide) (3) was prepared starting from pyridine‐2,6‐bis‐(3‐oxopropanenitrile) (1). Several new series of polysubstituted thiophenes and 1,3,4‐thiadiazoles incorporating 2,6‐pyridine moiety were efficiently synthesized. The newly synthesized compounds were evaluated for their in vitro anticancer activity against human cancer cell lines: hepatocellular liver carcinoma (HEPG2) and Caucasian breast adenocarcinoma (MCF‐7). Some of the newly synthesized compounds exhibited better activity than doxorubicin as a reference drug.
Microwave‐enhanced Efficient Synthesis of Some Polyfunctional Pyridazines
Authors: Kumar Jangid M. , Yadav T. , Yadav A. K.
Published: August 2013

Microwave‐enhanced highly efficient protocol for the synthesis of polyfunctional pyridazines beginning from 3,6‐dichloropyridazine in environmentally benign ionic liquids have been developed. The products obtained were 3‐amino‐6‐chloropyridazine, 3,6‐diaminopyridazine, and 3‐chloro‐6‐methoxypyridazine. These derivatives were then be converted to a variety of polyfunctional pyridazine derivatives. The ionic liquids used were 1‐n‐butyl‐3‐methylimidazolium hydroxide/tetrafluoroborate/hexafluorophosphate and 1,3‐di‐n‐butylimidazolium hydroxide. This powerful strategy is less time‐consuming green methodology. The ionic liquid employed may be recovered and recycled.
Coumarins: Facile and Expeditious Synthesis via Keggin‐Type Heteropolycompounds under Solvent‐Free Condition
Authors: Rafiee Ezzat , Fakhri Akram , Joshaghani Mohammad
Published: August 2013

Different Keggin‐type heteropolycompounds were used in Pechmann reaction to obtain biologically active coumarins. Effect of solvent, catalyst loading, and molar ratios of substrates was studied to introduce the best reaction condition. The optimized reaction condition was extended to Pechmann reaction of methylacetoacetate with various monohydric and polyhydric phenols. This rapid procedure afforded structurally diverse coumarins with high to excellent yields. Short reaction times, simple work‐up, and mild reaction conditions were advantages of this method. The optimized catalysts were reusable for four runs.
Selective reactivation of human herpesvirus 6 in patients with autoimmune connective tissue diseases
Authors: Broccolo Francesco , Drago Francesco , Cassina Giulia , Fava Andrea , Fusetti Lisa , Matteoli Barbara , Ceccherini‐Nelli Luca , Sabbadini Maria Grazia , Lusso Paolo , Parodi Aurora , Malnati Mauro S.
Published: August 2013

Viral infections have been associated with autoimmune connective tissue diseases. To evaluate whether active infection by Epstein–Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus (HHV)‐6, ‐7, ‐8, as well as parvovirus B19 (B19V) occur in patients with autoimmune connective tissue diseases, viral DNA loads were assessed in paired samples of serum and peripheral blood mononuclear cells (PBMCs) of 115 patients affected by different disorders, including systemic sclerosis, systemic, and discoid lupus erythematosus, rheumatoid arthritis, and dermatomyositis. Two additional groups, patients affected by inflammatory diseases (n = 51) and healthy subjects (n = 58) were studied as controls. The titers of anti‐HHV‐6 and anti‐EBV antibodies were also evaluated. Cell‐free HHV‐6 serum viremia was detected in a significantly higher proportion of connective tissue diseases patients compared to controls (P < 0.0002); a significant association between HHV‐6 reactivation and the active disease state was found only for lupus erythematosus (P = 0.021). By contrast, the rate of cell‐free EBV viremia was similar in patients and controls groups. Cell‐free CMV, HHV‐8, and B19V viremia was not detected in any subject. Anti‐HHV‐6 and anti‐EBV early antigen IgG titers were both significantly higher in autoimmune diseases patients as compared to healthy controls, although they were not associated with the presence of viremia. EBV, HHV‐6, ‐7 prevalence and viral load in PBMCs of patients with connective tissue diseases and controls were similar. These data suggest that HHV‐6 may act as a pathogenic factor predisposing patients to the development of autoimmune connective tissue diseases or, conversely, that these disorders may predispose patients to HHV‐6 reactivation. J Med. Virol. 85:1925–1934, 2013. © 2013 Wiley Periodicals, Inc.
Kinetics of the Neutralizing Antibody Response to Respiratory Syncytial Virus Infections in a Birth Cohort
Authors: Sande C.J. , Mutunga M.N. , Okiro E.A. , Medley G.F. , Cane P.A. , Nokes D.J.
Published: August 2013

The kinetics of respiratory syncytial virus (RSV) neutralizing antibodies following birth, primary and secondary infections are poorly defined. The aims of the study were to measure and compare neutralizing antibody responses at different time points in a birth cohort followed‐up over three RSV epidemics. Rural Kenyan children, recruited at birth between 2002 and 2003, were monitored for RSV infection over three epidemic seasons. Cord and 3‐monthly sera, and acute and convalescent sera following RSV infection, were assayed in 28 children by plaque reduction neutralization test (PRNT). Relative to the neutralizing antibody titers of pre‐exposure control sera (1.8 log10 PRNT), antibody titers following primary infection were (i) no different in sera collected between 0 and 0.4 months post‐infection (1.9 log10 PRNT, P = 0.146), (ii) higher in sera collected between 0.5 and 0.9 (2.8 log10 PRNT, P < 0.0001), 1.0–1.9 (2.5 log10 PRNT, P < 0.0001), and 2.0–2.9 (2.3 log10 PRNT, P < 0.001) months post‐infection, and (iii) no different in sera collected at between 3.0 and 3.9 months post‐infection (2.0 log10 PRNT, P = 0.052). The early serum neutralizing response to secondary infection (3.02 log10 PRNT) was significantly greater than the early primary response (1.9 log10 PRNT, P < 0.0001). Variation in population‐level virus transmission corresponded with changes in the mean cohort‐level neutralizing titers. It is concluded that following primary RSV infection the neutralizing antibody response declines to pre‐infection levels rapidly (∼3 months) which may facilitate repeat infection. The kinetics of the aggregate levels of acquired antibody reflect seasonal RSV occurrence, age, and infection history. J Med. Virol. 85:2020–2025, 2013. © 2013 The Authors. Journal of Medical Virology published by Wiley Periodicals, Inc.
Time resolved Raman spectroscopy for depth analysis of multi‐layered mineral samples
Authors: Hooijschuur Jan‐Hein , Iping Petterson Ingeborg E. , Davies Gareth R. , Gooijer Cees , Ariese Freek
Published: August 2013

Time resolved Raman spectroscopy (TRRS) can provide subsurface information from multi‐layered samples of transparent and translucent evaporative and silicate minerals up to several centimetres thick. Depth information was obtained using 3‐ps pulsed laser excitation at 720 nm and a gated intensified charge‐coupled device detector with stepwise increasing delay times. Blocks of different minerals were used as first, second or third layers, and Raman spectra from deeper layers could be detected through 10 mm of translucent calcite and up to 40 mm of transparent halite crystals. Measurements by conventional confocal Raman, as well as spatially offset Raman spectroscopy were also successful in distinguishing different mineral layers. This study establishes the great potential for the use of Raman spectroscopy in future planetary exploration, where TRRS could be used as a non‐invasive tool for profiling the (sub‐)surface at millimetre‐depth resolution. Copyright © 2013 John Wiley & Sons, Ltd.
Underivatized amylose and cellulose as new stationary phases for hydrophilic interaction chromatography
Authors: Lehnert Petr , Douša Michal , Lemr Karel
Published: August 2013

Two polysaccharide stationary phases have been newly suggested for application in hydrophilic interaction chromatography (HILIC). Both columns (amylose‐silica, 250 × 4.6 mm, 5 μm and cellulose‐silica, 250 × 4.6 mm, 5 μm) demonstrated a satisfactory retention of polar compounds. The influence of the mobile‐phase composition (acetonitrile content, pH, salt concentration) on the retention was in agreement with the HILIC concept. The phases showed a very similar behavior, typical efficiency of about 50 000 plates/m, cellulose retained test compounds somewhat more strongly. Under the experimental conditions, electrostatic (non‐HILIC‐type) interactions due to the dissociation of silanol groups on the silica surface did not influence the retention, noticeably. The applicability of polysaccharide stationary phases for the chromatography of polar compounds was proven by the separation of mixtures of sugars (fructose, glucose, saccharose, maltose, trehalose) or vitamins (nicotinamide, pyridoxine, riboflavin, thiamine, nicotinic acid, ascorbic acid).
Influence of β‐Cyclodextrin on the Free‐Radical Copolymerization of N‐(4‐Methylphenyl)maleimide with N‐Vinylpyrrolidone in Water
Authors: Schönenberg Lisa , Ritter Helmut
Published: August 2013

Randomly methylated β‐cyclodextrin (me‐β‐CD) is used to include the hydrophobic monomer N‐(4‐methylphenyl)maleimide (MPM) (1) yielding the corresponding water‐soluble host‐guest structure 1a. Free‐radical copolymerization of 1a with N‐vinylpyrrolidone (NVP) (2) is performed and the reactivity ratios r1 and r2 are determined: 0.24 ± 0.03 (r2) and 1.10 ± 0.05 (r1a). This indicates a preferred incorporation of complexed maleimide into the copolymer chain. In contrast to that, the copolymerization of the uncomplexed monomers 1 and 2 is carried out using organic solvent (DMF/H2O) showing reactivity ratios corresponding to nearly alternating copolymerization (r2 = 0.09 ± 0.02; r1 = 0.34 ± 0.03).

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Biobased Copolymers Composed of l‐Lactic Acid and Side‐Chain‐Substituted Lactic Acids: Synthesis, Properties, and Solid‐State Structure
Authors: Marubayashi Hironori , Asai Shigeo , Hikima Takaaki , Takata Masaki , Iwata Tadahisa
Published: August 2013

Various biobased copolyesters composed of l‐lactic acid (LLA) and side‐chain‐substituted lactic acids (SLAs) with high molecular weight and LLA‐rich composition are synthesized by direct solution polycondensation. Glycolic acid, 2‐hydroxyisobutyric acid, (S)‐2‐hydroxy‐3‐methylbutanoic acid (LVOH), and (S)‐2‐hydroxy‐4‐methylpentanoic acid (LLOH) are chosen as SLAs. Wide‐angle X‐ray diffraction (WAXD) and small‐angle X‐ray scattering (SAXS) reveal that the substituent size of the SLAs determines whether or not SLA units are included in crystallites of the LLA sequences. Unlike poly(l‐lactic acid), tensile necking is seen in the copolymers with 2 mol% LVOH and with 6 mol% LLOH. Enzymatic degradation is accelerated with increasing SLA content. Especially for 6 mol% LLOH, the SLA introduction improves both the mechanical properties and the enzymatic degradability.

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Isometries on and monotone functions
Authors: Boza Santiago , Soria Javier
Published: August 2013

We study necessary and sufficient conditions on a bounded operator T defined on the Hilbert space to be an isometry and show that, under suitable hypotheses, it suffices to restrict T to a smaller class of functions (e.g., if , to the cone of positive and decreasing functions). We also consider the problem of characterizing the sets for which the orthogonal projection of the operator T on is also an isometry. Finally, we illustrate our results with several examples involving classical operators on different settings.
From Random Coil Polymers to Helical Structures Induced by Carbon Nanotubes and Supramolecular Interactions
Authors: Huang Kai‐Wei , Wu Yu‐Rong , Jeong Kwang‐Un , Kuo Shiao‐Wei
Published: August 2013

A simple method is reported for the preparation of double‐helical structures through a series of achiral random and block copolymers poly(styrene‐co‐4‐vinylbenzyl triazolylmethyl methylthymine) (PS‐co‐PVBT) with various T units on the side chains through click reactions of poly(styrene‐co‐4‐vinylbenzyl azide) (PS‐co‐PVBN3) with propargyl thymine (PT) and also the synthesis of the A‐appended pyrene derivative (A‐Py) through click chemistry. This double‐helical structure is observed from achiral random‐coil polystyrene (PS) main chains, stabilized through the combination of multiple A–T hydrogen bonds, and π–π stacking between pyrene units and single‐walled carbon nanotubes (SWCNTs).

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Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography
Authors: Klein Steven , Van Lienden Krijn P. , Van't Veer Marcel , Smit Jeroen M. , Werker Paul M.N.
Published: August 2013

Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohen's Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohen's Kappa of 0.64, indicating “substantial agreement of stenosis severity scores” was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI95%:60–91), and a specificity of 98% (CI95%: 97–99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation. © 2013 Wiley Periodicals, Inc. Microsurgery 33:539–544, 2013.
The preventive role of breadfruit against inflammation‐associated epithelial carcinogenesis in mice
Authors: Lin Jer‐An , Chen Hsiang‐Chi , Yen Gow‐Chin
Published: August 2013

Artocarpus communis has been identified as a rich source of flavonoids and has been gaining attention for its potential chemopreventive abilities. In this study, methanol extracts from the fruit of A. communis (MEFA) and leaf of A. communis (MELA) were prepared, and their effects on inflammation‐associated skin tumorigenesis were assessed using mouse models, including 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) induced cutaneous inflammation as well as 7,12‐dimethylbenz[α]anthracene (DMBA) initiated and TPA‐promoted skin tumorigenesis. According to the results, both MEFA and MELA decreased the intensity of leukocyte infiltration in mouse dorsal skin and cutaneous edema induced by TPA, which appeared to be mediated by inhibition of proinflammatory genes (inducible nitric oxide synthase, cyclooxygenase‐2 (COX‐2), tumor necrosis factor‐α (TNF‐α), IL‐1β, and IL‐6) and proinflammatory mediators (TNF‐α, IL‐1β, and Prostaglandin E2). In addition, topical application with MEFA or MELA effectively attenuated tumor incidence, multiplicity, volume, malignancy as well as angiogenesis of TPA‐stimulated skin tumor promotion in DMBA‐initiated mice. Notably, immunohistochemical stain showed that MEFA and MELA attenuated COX‐2 expression of both skin and tumor tissues in different animal tests, which may be closely related to the suppression of nuclear factor kappa B/activator protein signaling networks. These findings first demonstrate that flavonoid‐rich A. communis may exert potent anti‐inflammatory activity through modulation of COX‐2 in TPA‐activated skin and tumor tissues.
Evaluation of Adhesive and Elastic Properties of Polymers by the BG Method
Authors: Borodich Feodor M. , Galanov Boris A. , Gorb Stanislav N. , Prostov Mikhail Y. , Prostov Yuriy I. , Suarez‐Alvarez Maria M.
Published: August 2013

The work of adhesion and the elastic contact modulus of the pair of interacting materials are a prerequesite in order to study adhesive interactions between solids. For small material samples, the contact modulus is usually evaluated by depth‐sensing indentation of sharp indenters, while the work of adhesion is determined by direct measurements of pull‐off force of a sphere. These measurements are unstable due to the instability of the load–displacement diagrams under tension, and they can be greatly affected by the roughness of the contacting solids. Using experiments for polyvinylsiloxane samples, it is shown how the work of adhesion and the elastic contact modulus of materials may be quantified using the BG method. This is a non‐direct method based on an inverse analysis of a stable region of the experimental force–displacement curves. The BG method is simple and robust. Nevertheless, the extracted values of both characteristics vary within the same polymer sample due to contact areas that possess interacting polymer molecules in various orientations. It was found that the average values of characteristics are very stable and the work of adhesion of polymers may be treated as a material parameter in statistical sense.
Analysis of pile subjected to torsion in multi‐layered soil
Authors: Misra A. , Saggu Rajni , Basu D. , Chakraborty T.
Published: August 2013

A new method of analysis of piles in multi‐layered elastic soil subjected to a torque at the head is developed. The differential equation governing the angle of twist in the pile is derived using the variational principles of mechanics. The method of initial parameters is used to obtain closed‐form solutions of the angle of twist and torque in the pile as a function of depth. The inputs required for the analysis are shear moduli of pile and soil, pile geometry and thickness of soil layers. Copyright © 2013 John Wiley & Sons, Ltd.
In situ δ18O and Mg/Ca analyses of diagenetic and planktic foraminiferal calcite preserved in a deep‐sea record of the Paleocene‐Eocene thermal maximum
Authors: Kozdon Reinhard , Kelly D. C. , Kitajima K. , Strickland A. , Fournelle J. H. , Valley J. W.
Published: August 2013

We report δ18O and minor element (Mg/Ca, Sr/Ca) data acquired by high‐resolution, in situ secondary ion mass spectrometry (SIMS) from planktic foraminiferal shells and 100–500 µm sized diagenetic crystallites recovered from a deep‐sea record (ODP Site 865) of the Paleocene‐Eocene thermal maximum (PETM). The δ18O of crystallites (~1.2‰ Pee Dee Belemnite (PDB)) is ~4.8‰ higher than that of planktic foraminiferal calcite (−3.6‰ PDB), while crystallite Mg/Ca and Sr/Ca ratios are slightly higher and substantially lower than in planktic foraminiferal calcite, respectively. The focused stratigraphic distribution of the crystallites signals an association with PETM conditions; hence, we attribute their formation to early diagenesis initially sourced by seafloor dissolution (burndown) ensued by reprecipitation at higher carbonate saturation. The Mg/Ca ratios of the crystallites are an order of magnitude lower than those predicted by inorganic precipitation experiments, which may reflect a degree of inheritance from “donor” phases of biogenic calcite that underwent solution in the sediment column. In addition, SIMS δ18O and electron microprobe Mg/Ca analyses that were taken within a planktic foraminiferal shell yield parallel increases along traverses that coincide with muricae blades on the chamber wall. The parallel δ18O and Mg/Ca increases indicate a diagenetic origin for the blades, but their δ18O value (−0.5‰ PDB) is lower than that of crystallites suggesting that these two phases of diagenetic carbonate formed at different times. Finally, we posit that elevated levels of early diagenesis acted in concert with sediment mixing and carbonate dissolution to attenuate the δ18O decrease signaling PETM warming in “whole‐shell” records published for Site 865.
Hydrographic changes in the tropical and extratropical Pacific during the last deglaciation
Authors: Rodríguez‐Sanz Laura , Mortyn P. Graham , Herguera Juan C. , Zahn Rainer
Published: August 2013

Fine‐scale, paired Mg/Ca‐δ18O profiles (Globigerinoides ruber white, sensu lato) from the San Lázaro Basin (SLB) at 25°N in the Northeast Pacific reveal a transition from a predominant presence of tropical/subtropical waters during the last glacial termination (T1) to an increasing influence of fresh and cold California Current waters toward the Holocene. Changing atmospheric circulation patterns over the Northeast Pacific in step with the demise of the Northern Hemisphere ice sheets and/or with a shift from El Niño‐ to La Niña‐like conditions toward the Holocene are prime candidates to explain this water mass change. δ18OSW‐IVC increases of ~0.5–0.7‰ during the Younger Dryas (YD) and Heinrich stadial 1 (HS1) at the SLB are observed in a number of δ18OSW‐IVC records from the tropical Pacific, more directly influenced by changes in the position of the Intertropical Convergence Zone (ITCZ). Conditioning by ITCZ migration of the tropical Pacific Ocean towards salinity increase during YD and HS1, and the subsequent advection of those water masses as far north as 25°N likely accounted for the reconstructed hydrographical changes at the SLB. A larger influence of tropical water masses as far north as 25°N plausibly contributed to changes in the atmospheric moisture transports to western North America and affected the regional hydrological cycle across T1. Finally, the fine‐scale resolution of our δ18OSW‐IVC record allows pinpointing a shift from relative salty to fresh surface conditions at ~16.2 ka, signaling that the two‐phase structure of HS1 is plausibly a ubiquitous feature of the northern tropical to extratropical ocean‐atmosphere dynamics.
Development and characterization of co‐polyimide/attapulgite nanocomposites with highly enhanced thermal and mechanical properties
Authors: Zhang Ying , Shen Jie , Li Qing , Xu Zushun , Yeung Kelvin W. K. , Yi Changfeng , Zhang Quanyuan
Published: August 2013

A series of co‐polyimide/attapulgite (co‐PI/AT) nanocomposites have been successfully fabricated from anhydride‐terminated polyimide (PI) and γ‐aminopropyltriethoxysilane (APTES)‐modified fibrous attapulgite (AT). Co‐PI was prepared from 4,4′‐diaminodiphenyl ether (ODA), 4,4′‐oxydiphthalic anhydride (ODPA), and 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) by using the method of chemical imidization. Different amount of AT (0, 1, 3, 5, 7 wt%) were introduced into co‐PI via strong covalent interactions between terminal anhydride and amino groups. The properties of co‐PI/AT nanocomposites such as morphology, thermal stability, mechanical properties, and UV transparency were investigated to illustrate the contribution of the introduction of AT into the PI matrix. FTIR spectra and SEM images revealed that network structures between co‐PI and AT are formed, which endowed the nanocomposites with outstanding thermal and mechanical properties. The co‐PI/AT nanocomposites exhibited excellent thermal and thermo‐oxidative stabilities with the onset decomposition temperature and 10% weight loss temperature increasing to the ranges of 502–510°C and 555–562°C from 480°C to 526°C for the pristine co‐PI, respectively. The glass transition temperatures of these co‐PI/AT nanocomposites increased to the range of 231–238°C from 222°C for pure co‐PI. The co‐PI/AT nanocomposites films were found to be transparent, flexible, and tough. By incorporating 5 wt% AT into the co‐PI matrix, the tensile strength, elongation at break, and Young's modulus of the co‐PI/AT nanocomposites reached 110.7 MPa, 14.5%, and 1.2 GPa, respectively, which are 50%, 120%, and 80% increased compared with the values of pristine PI. POLYM. COMPOS., 35:86–96, 2014. © 2013 Society of Plastics Engineers
Performance Comparison Between Polycrystalline Thin‐film and Single‐crystal Solar Cells
Authors: Sites James R. , Liu Xiaoxiang
Published: August 2013

Recent progress has increased the efficiency of poly crystalline thin‐film solar cells to roughly two‐thirds that of single‐crystal cells of comparable bandgap. The largest remaining difference is the excessive forward recombination current, which is larger by a factor of 20 for the best CuInSe2‐based cells, and by more than a factor of 100 for CdTe cells. Collection loss, related to diffusion length, is nearly as important for the CuInSe2‐based cells. It is an open question how much additional reduction in these two tosses should he anticipated. However, other losses in thin‐film cells due to window‐layer absorption, reflection and grid coverage will almost certainly be reduced, so that efficiencies equal to 80% of crystalline counterparts should be a viable 5‐year target.
Minority Carrier Collection Enhancement Model for the Deeply Grooved Solar Cell
Authors: Jackson Edward L. , Barnett Allen M.
Published: August 2013

Although many solar cell designs for low‐concentration linear focus applications have utilized the ‘prismatic cover’ for reducing gridline shadings the deeply grooved solar cell represents an effort to integrate the prismatic cover into the basic device design for performance enhancement. The design is based on deep (140‐μm) grooves in 〈100〉 orientation silicon, with an active‐area silicon ‘ridge’ between gridlines. The silicon ridge should improve minority carrier collection efficiency as compared to planar designs, due to the two‐dimensional nature of current collection, and the placement of light on the ridge by the focus of the prismatic cover. This article describes the enhancement mechanism by using a model based on the superposition of two specific solutions of the transport equation. The enhancement model is in support of the approximation that for one‐dimensional numerical modeling, the ‘effective’ diffusion length is the sum of the bulk silicon diffusion length and the height of the ridge. Data collected from prototype solar cells provide some experimental support for the model, but difficulty in fabrication using typical semiconductor processing has limited full realization of the structure.
Application of Static Concentrators to Photovoltaic Roof Tiles
Authors: Bowden S. , Wenham S. R. , Green M. A.
Published: August 2013

An innovative three‐dimensional approach to static concentrators has keen developed that offers increased concentration ratios with slimmer designs than previous two‐dimensional static concentrator photovoltaic modules. Slimmer designs are essential for a practical static concentrator because they allow an economically viable implementation by using less material and by allowing incorporation into building structures such as roofing tiles. In this paper, the theoretical performance limits are discussed and a design is developed that achieves a concentration ratio of 3.6:1 while still capturing 90% of the annual irradiation without tracking the sun. The thermal performance of the static concentrator module is analysed to show that any efficiency loss due to cell heating is matched by the efficiency gain due to concentration. The efficiency of the module described is predicted to he greater than that of a conventional fiat plate module.
Event Report Sunrayce 95
Authors: Basore Paul A.
Published: August 2013

Thirty‐six university teams from Canada, Mexico and the United States raced their solar‐powered cars from Indiana to Colorado during June 1995. The event, called Sunrayce 95, is designed to provide a stimulating educational opportunity for students of science and engineering, while educating the public about the exciting prospect of environmentally clean photovoltaic energy. The race was the fastest and closest ever for a collegiate solar‐car event, with the winner decided by only 19 minutes and one team averaging over 80 kph for 1 day of the race.