bluuebunny/crossref_metadata_2025 huggingface dataset:
A preliminary study of thermosphere and mesosphere wind observed by Fabry‐Perot over Kelan, China
Authors: Yu Tao , Huang Cong , Zhao Guangxin , Mao Tian , Wang Yungang , Zeng Zhongcao , Wang Jingsong , Xia Chunliang
Published: May 2014

A Fabry‐Perot interferometer (FPI) system was deployed in Kelan (38.7°N, 111.6°E), center China in November 2011, which observes the airglows at wavelengths of 892.0 nm, 557.7 nm, and 630.0 nm from OH and OI emissions in the upper atmosphere, to derive the wind and temperature at heights around 87 km, 97 km, and 250 km, respectively. From late 2011 through 2013 a series of more than 4500 measurements at each height are validated according to manufacture data quality criteria. By using these data, the morphology of wind in the mesosphere and thermosphere is investigated in this study. Preliminary results are as follows: (1) As for the diurnal variation, meridional and zonal winds at heights of 87 km and 97 km, which are derived through 892.0 nm and 557.7 nm airglows, usually range from −50 m/s to 30 m/s and −50 m/s to 50 m/s, respectively, with typical random errors of about 6–10 m/s at 87 km and 2–3 m/s at 97 km. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, westward at middle night, and back to eastward at dawn. The monthly mean winds are in good agreement with those of HWM93 results. Meridional and zonal winds at a height of 250 km, which are derived through 630.0 nm nightglow, range from −110 m/s to 80 m/s with typical random errors of about 8–10 m/s. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, zero at middle night, and westward at dawn; and they are also well consistent with HWM93 results. (2) As for the seasonal variation, meridional winds at the heights of 87 km and 97 km have a visible annual variation at 12–17 LT and with a little semiannual variation at all other hours, but the zonal winds at the heights of 87 km and 97 km have a semiannual variation all night. The seasonal dependence of the winds, both meridional and zonal winds, at the height of 250 km is generally annual, but isolated cases of semiannual variation are observed. (3) The horizontal winds at 250 km evidently respond to the two storms of July 2012, apparent enhancement of the velocity of the southwestward wind. But no other obvious storm effects can be found from the winds at 87 km and 97 km during the same period.
A two‐magma chamber model as a source of deformation at Grímsvötn Volcano, Iceland
Authors: Reverso Thomas , Vandemeulebrouck Jean , Jouanne François , Pinel Virginie , Villemin Thierry , Sturkell Erik , Bascou Pascale
Published: May 2014

Grímsvötn Volcano is the most active volcano in Iceland, and its last three eruptions were in 1998, 2004, and 2011. Here we analyze the displacement around Grímsvötn during these last three eruptive cycles using 10 GPS stations. The observed displacements in this region generally contain a linear component of tectonic and glacio‐isostatic origin, in agreement with the previously estimated values of plate motions and vertical rebound. Larger amplitude deformation observed close to Grímsvötn at the GFUM continuous GPS station clearly reflects a major volcanic contribution superimposed on a tectonic component. We estimate and subtract the tectonic trend at this station using regional observed displacement. The direction and pattern of the residual volcanic displacement (for coeruptive and intereruptive periods) are consistent for all three of these eruptive cycles. The posteruptive inflation is characterized by an exponential trend, followed by a linear trend. In this study, we explain this temporal behavior using a new analytic model that has two connected magma chambers surrounded by an elastic medium and fed by a constant basal magma inflow. During the early posteruptive phase, pressure readjustment occurs between the two reservoirs, with replenishment of the shallow chamber from the deep chamber. Afterward, due to the constant inflow of magma into the deep reservoir, the pressurization of the system produces linear uplift. A large deep reservoir favors magma storage rather than surface emission. Based on displacement measured at GFUM station, we estimate an upper limit for the radius of the deep reservoir of ∼10 km.
The oceanic response of the Turkish Straits System to an extreme drop in atmospheric pressure
Authors: Book Jeffrey W. , Jarosz Ewa , Chiggiato Jacopo , Beşiktepe Şükrü
Published: May 2014

Moorings across all four entry/exit sections of the Dardanelles Strait and the Bosphorus Strait simultaneously measured the response of the Turkish Straits System to the passage of a severe cyclonic storm that included an atmospheric pressure drop of more than 30 mbar in less than 48 h. The bottom pressure response at the Aegean Sea side of the Dardanelles Strait was consistent with an inverted barometer response, but the response at the other sections did not follow an inverted barometer, leading to a large bottom pressure gradient through the Turkish Straits System. Upper‐layer flow toward the Aegean Sea was reversed by the storm and flow toward the Black Sea was greatly enhanced. Bottom pressure across the Sea of Marmara peaked 6 h after the passage of the storm's minimum pressure. The response on the Dardanelles side was a combination of sea elevation and pycnocline depth rise, and the response on the Bosphorus side was an even greater sea elevation rise and a drop in pycnocline depth. The peak in bottom pressure in the Sea of Marmara was followed by another reverse in the flow through the Dardanelles Strait as flow was then directed away from the Sea of Marmara in both straits. A simple conceptual model without wind is able to explain fluctuations in bottom pressure in the Sea of Marmara to a 0.89–0.96 level of correlation. This stresses the importance of atmospheric pressure dynamics in driving the mass flux of the Turkish Strait System for extreme storms.
Ammonium deficiency caused by heterogeneous reactions during a super Asian dust episode
Authors: Hsu Shih‐Chieh , Lee Celine Siu Lan , Huh Chih‐An , Shaheen Robina , Lin Fei‐Jan , Liu Shaw Chen , Liang Mao‐Chang , Tao Jun
Published: May 2014

Mineral dust particles exert profound impacts on air quality, visibility, and ocean biogeochemistry. Interactions between dust particles and other anthropogenic pollutants modify not only the size spectrum and morphology but also physicochemical properties of dust particles, thereby affecting their radiative properties and ability to act as cloud condensation nuclei and in turn their impact on climate. Here we report field observations on the surface chemical transformations in a super Asian dust plume captured in coastal areas of China and the adjacent marginal seas. The dust plume showed enhanced concentrations of sulfate, nitrate, and calcium along with a decrease in ammonium. The percentages of total Ca in water‐soluble form increased from an intrinsic value of ~5% to 25–40% at four stations along the path of the dust plume. From these increases, we estimated the extent to which carbonate was modified by heterogeneous reactions and calculated that the enhanced sulfate and nitrate could account for 40–60% of the observed concentrations. Our observation suggests that the formation of ammonium sulfate via the H2SO4‐NH3‐H2O ternary system was impeded by heterogeneous reactions in the marine boundary layer when dust loads exceeded a certain threshold. A conceptual model is proposed to elucidate the heterogeneous reactions during the super Asian dust event and their impacts on atmospheric chemistry.
Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium
Authors: Acosta Navarro J. C. , Smolander S. , Struthers H. , Zorita E. , Ekman A. M. L. , Kaplan J. O. , Guenther A. , Arneth A. , Riipinen I.
Published: May 2014

We investigated the millennial variability (1000 A.D.–2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund‐Potsdam‐Jena‐General Ecosystem Simulator (LPJ‐GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short‐term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr−1 (13% and 19% less than during 1750–1850 and 1000–1200, respectively), and LPJ‐GUESS emissions were 323 TgC yr−1(15% and 20% less than during 1750–1850 and 1000–1200, respectively). Monoterpene emissions were 89 TgC yr−1(10% and 6% higher than during 1750–1850 and 1000–1200, respectively) in MEGAN, and 24 TgC yr−1 (2% higher and 5% less than during 1750–1850 and 1000–1200, respectively) in LPJ‐GUESS. MEGAN sesquiterpene emissions were 36 TgC yr−1(10% and 4% higher than during 1750–1850 and 1000–1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.
Improved dust representation in the Community Atmosphere Model
Authors: Albani S. , Mahowald N. M. , Perry A. T. , Scanza R. A. , Zender C. S. , Heavens N. G. , Maggi V. , Kok J. F. , Otto‐Bliesner B. L.
Published: May 2014

Aerosol‐climate interactions constitute one of the major sources of uncertainty in assessing changes in aerosol forcing in the anthropocene as well as understanding glacial‐interglacial cycles. Here we focus on improving the representation of mineral dust in the Community Atmosphere Model and assessing the impacts of the improvements in terms of direct effects on the radiative balance of the atmosphere. We simulated the dust cycle using different parameterization sets for dust emission, size distribution, and optical properties. Comparing the results of these simulations with observations of concentration, deposition, and aerosol optical depth allows us to refine the representation of the dust cycle and its climate impacts. We propose a tuning method for dust parameterizations to allow the dust module to work across the wide variety of parameter settings which can be used within the Community Atmosphere Model. Our results include a better representation of the dust cycle, most notably for the improved size distribution. The estimated net top of atmosphere direct dust radiative forcing is −0.23 ± 0.14 W/m2 for present day and −0.32 ± 0.20 W/m2 at the Last Glacial Maximum. From our study and sensitivity tests, we also derive some general relevant findings, supporting the concept that the magnitude of the modeled dust cycle is sensitive to the observational data sets and size distribution chosen to constrain the model as well as the meteorological forcing data, even within the same modeling framework, and that the direct radiative forcing of dust is strongly sensitive to the optical properties and size distribution used.
Impact of large‐scale climate extremes on biospheric carbon fluxes: An intercomparison based on MsTMIP data
Authors: Zscheischler Jakob , Michalak Anna M. , Schwalm Christopher , Mahecha Miguel D. , Huntzinger Deborah N. , Reichstein Markus , Berthier Gwenaëlle , Ciais Philippe , Cook Robert B. , El‐Masri Bassil , Huang Maoyi , Ito Akihiko , Jain Atul , King Anthony , Lei Huimin , Lu Chaoqun , Mao Jiafu , Peng Shushi , Poulter Benjamin , Ricciuto Daniel , Shi Xiaoying , Tao Bo , Tian Hanqin , Viovy Nicolas , Wang Weile , Wei Yaxing , Yang Jia , Zeng Ning
Published: May 2014

Understanding the role of climate extremes and their impact on the carbon (C) cycle is increasingly a focus of Earth system science. Climate extremes such as droughts, heat waves, or heavy precipitation events can cause substantial changes in terrestrial C fluxes. On the other hand, extreme changes in C fluxes are often, but not always, driven by extreme climate conditions. Here we present an analysis of how extremes in temperature and precipitation, and extreme changes in terrestrial C fluxes are related to each other in 10 state‐of‐the‐art terrestrial carbon models, all driven by the same climate forcing. We use model outputs from the North American Carbon Program Multi‐scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP). A global‐scale analysis shows that both droughts and heat waves translate into anomalous net releases of CO2 from the land surface via different mechanisms: Droughts largely decrease gross primary production (GPP) and to a lower extent total respiration (TR), while heat waves slightly decrease GPP but increase TR. Cold and wet periods have a smaller opposite effect. Analyzing extremes in C fluxes reveals that extreme changes in GPP and TR are often caused by strong shifts in water availability, but for extremes in TR shifts in temperature are also important. Extremes in net CO2 exchange are equally strongly driven by deviations in temperature and precipitation. Models mostly agree on the sign of the C flux response to climate extremes, but model spread is large. In tropical forests, C cycle extremes are driven by water availability, whereas in boreal forests temperature plays a more important role. Models are particularly uncertain about the C flux response to extreme heat in boreal forests.
Optimization of legacy lidar data sets for measuring near‐field earthquake displacements
Authors: Glennie Craig L. , Hinojosa‐Corona Alejandro , Nissen Edwin , Kusari Arpan , Oskin Michael E. , Arrowsmith J. Ramon , Borsa Adrian
Published: May 2014

Airborne lidar (light detection and ranging) topography, acquired before and after an earthquake, can provide an estimate of the coseismic surface displacement field by differencing the preevent and postevent lidar point clouds. However, estimated displacements can be contaminated by the presence of large systematic errors in either of the point clouds. We present three‐dimensional displacements obtained by differencing airborne lidar point clouds collected before and after the El Mayor–Cucapah earthquake, a Mw 7.2 earthquake that occurred in 2010. The original surface displacement estimates contained large, periodic artifacts caused by systematic errors in the preevent lidar data. Reprocessing the preevent data, detailed herein, removed a majority of these systematic errors that were largely due to misalignment between the scanning mirror and the outgoing laser beam. The methodology presented can be applied to other legacy airborne laser scanning data sets in order to improve change estimates from temporally spaced lidar acquisitions.
An observation of sea‐spray microphysics by airborne Doppler radar
Authors: Fairall C. W. , Pezoa S. , Moran K. , Wolfe D.
Published: May 2014

This paper describes observations and analysis of Doppler radar data from a down‐looking 94 GHz (W‐Band) system operated from a NOAA WP‐3 Orion research aircraft in Tropical Storm (TS) Karen. The flight took place on 5 October 2013; Karen had weakened with maximum winds around 20 m s−1. Doppler spectral moments from the radar were processed to retrieve sea‐spray microphysical properties (drop size and liquid water mass concentration) profiles in the height range 75–300 m above the sea surface. In the high wind speed regions of TS Karen (U10 > 15 m s−1), sea spray was observed with a nominal mass‐mode radius of about 40 µm, a radar‐weighted gravitational fall velocity of about 1 m s−1, and a mass concentration of about 10−3 gm−3 at 75 m. Spray‐drop mass concentration declined with height to values of about 10−4 gm−3 at 300 m. Drop mass decreased slightly more slowly with increasing height than predicted by surface‐layer similarity theory for a balance of turbulent diffusion vs fall velocity.
Influence of water ice clouds on nighttime tropical temperature structure as seen by the Mars Climate Sounder
Authors: Wilson R. John , Guzewich Scott D.
Published: May 2014

An analysis of nighttime temperature and water ice cloud extinction profiles from the Mars Climate Sounder aboard the Mars Reconnaissance Orbiter provides evidence for the close relationship between tropical temperature structure and water ice clouds. The tropical temperature structure that evolves over the spring and summer seasons is closely coupled to the waxing and waning of tropical cloud activity. The presence of strong elevated nighttime temperature inversions in the Tharsis region is a robust feature of the equatorial atmosphere during the Ls = 0–135° season, with little interannual variation seen in the three Mars years examined. Mars global circulation model simulations imply that cloud radiative forcing plays a dominant role in the seasonal modulation of the observed longitude distribution of warm and cold anomalies in surface and low‐altitude air temperatures, respectively.
Long‐term hydrological changes of the Aral Sea observed by satellites
Authors: Shi Wei , Wang Menghua , Guo Wei
Published: May 2014

The Aral Sea has been shrinking since the former Soviet Union constructed irrigation projects to divert water from its main rivers in the 1960s. The diminishing of the Aral Sea is “one of the worst environmental disasters in the world” (from United Nations Secretary‐General Ban Ki‐moon). In this study, 33 years of satellite observations from Advanced Very High Resolution Radiometer (AVHRR) and 21 years of satellite altimetry sea level data from TOPEX/Poseidon, Jason‐1, and Jason‐2 are used to quantify the long‐term hydrological changes in the Aral Sea. A simple algorithm with AVHRR channels 1 and 2 albedo is developed to identify and discriminate the water pixels from land and cloud. Thus, monthly water coverage in the region can be reliably generated. The water coverage maps since 1981 show constant decline of the Aral Sea. The coverage dropped from ∼4.7–4.8 × 104 km2 in 1981 to about ¼ of this value in the recent years. In fact, drastic hydrological change was observed in the main Aral Sea during the 2000s. In the South Aral Sea, sea level shows a steady decrease from 35 m above sea level to <26 m since 1993. Total loss of water storage since 1993 is estimated to be ∼2.0 × 102 km3 for the South Aral Sea with a rate of ∼16−20 km3/yr before 2002, and a smaller value after 2002. In 1990, the North Aral Sea was observed to separate from the main Aral Sea. Water coverage, sea level, and total water storage were kept relatively stable for the period between 1993 and 2013 in the North Aral Sea. A water level increase and coverage expansion occurred during the 2005−2006 period when a dam was built in 2005 between the North Aral Sea and the South‐East Aral Sea.
A mechanistic modeling and data assimilation framework for Mojave Desert ecohydrology
Authors: Ng Gene‐Hua Crystal , Bedford David R. , Miller David M.
Published: May 2014

This study demonstrates and addresses challenges in coupled ecohydrological modeling in deserts, which arise due to unique plant adaptations, marginal growing conditions, slow net primary production rates, and highly variable rainfall. We consider model uncertainty from both structural and parameter errors and present a mechanistic model for the shrub Larrea tridentata (creosote bush) under conditions found in the Mojave National Preserve in southeastern California (USA). Desert‐specific plant and soil features are incorporated into the CLM‐CN model by Oleson et al. (2010). We then develop a data assimilation framework using the ensemble Kalman filter (EnKF) to estimate model parameters based on soil moisture and leaf‐area index observations. A new implementation procedure, the “multisite loop EnKF,” tackles parameter estimation difficulties found to affect desert ecohydrological applications. Specifically, the procedure iterates through data from various observation sites to alleviate adverse filter impacts from non‐Gaussianity in small desert vegetation state values. It also readjusts inconsistent parameters and states through a model spin‐up step that accounts for longer dynamical time scales due to infrequent rainfall in deserts. Observation error variance inflation may also be needed to help prevent divergence of estimates from true values. Synthetic test results highlight the importance of adequate observations for reducing model uncertainty, which can be achieved through data quality or quantity.
Highly scalable ZIF‐based mixed‐matrix hollow fiber membranes for advanced hydrocarbon separations
Authors: Zhang Chen , Zhang Kuang , Xu Liren , Labreche Ying , Kraftschik Brian , Koros William J.
Published: May 2014

ZIF‐8/6FDA‐DAM, a proven mixed‐matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual‐layer ZIF‐8/6FDA‐DAM mixed‐matrix hollow fiber membranes with ZIF‐8 nanoparticle loading up to 30 wt % using the conventional dry‐jet/wet‐quench fiber spinning technique. The mixed‐matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed‐matrix dense films. Critical variables controlling successful formation of mixed‐matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high‐loading mixed‐matrix hollow fiber membranes with significantly enhanced selectivity for separation of condensable olefin/paraffin mixtures. Therefore, it represents a major step in the research area of advanced mixed‐matrix membranes. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2625–2635, 2014
The utility of restaging bone marrow biopsy in PET‐negative patients with diffuse large B‐cell lymphoma and baseline bone marrow involvement
Authors: Jackson Amie E. , Smeltzer Jacob P. , Habermann Thomas M. , Jones Jason M. , Burnette Brian , Ristow Kay , Wiseman Gregory A. , Macon William R. , Nowakowski Grzegorz S. , Witzig Thomas E.
Published: May 2014

Patients with diffuse large B‐cell lymphoma (DLBCL) and pre‐treatment bone marrow (BM) involvement require a restaging BM biopsy to document complete remission (CR). We investigated whether BM assessment by restaging PET‐CT could obviate the need for a repeat BM biopsy. Patients with DLBCL and a positive BM biopsy at diagnosis were identified from the Mayo Clinic Lymphoma Data Base. The concordance of BM status on restaging histopathology and PET‐CT reports and the positive (PPV) and negative predictive value (NPV) of PET‐CT were determined. One thousand eighty patients with DLBCL were evaluated and 69 patients (6%) had DLBCL involving the BM at diagnosis. Of 46 patients who completed frontline chemoimmunotherapy, 34 had a restaging PET‐CT and BM biopsy and were included in the analysis. Thirty‐three patients had a negative BM by both PET‐CT and BM biopsy; one patient had persistent BM involvement by biopsy and PET‐CT. Thus, restaging PET‐CT had 100% PPV and 100% NPV for assessing residual BM disease. The findings were validated in a prospective cohort of 68 DLBCL patients treated on a phase II clinical trial where four patients (6%) had DLBCL involving the BM at diagnosis. All had a negative BM by both restaging BM biopsy and PET‐CT. Compared with the gold standard of BM biopsy, PET‐CT had a 100% NPV to exclude residual BM disease after frontline therapy. If further validated, DLBCL practice guidelines and response criteria could be modified so that BM biopsy is no longer required to document CR if the restaging PET‐CT is negative. Am. J. Hematol. 89:865–867, 2014. © 2014 Wiley Periodicals, Inc.
Patterns in ritual tooth avulsion at Roonka
Authors: Durband Arthur C. , Littleton Judith , Walshe Keryn
Published: May 2014

Tooth avulsion is the intentional removal of one or more teeth for ritual or aesthetic reasons, or to denote group affiliation. Typically the maxillary incisors are the teeth most often selected for removal. Previous authors have discussed the presence of tooth avulsions in several individuals recovered from Roonka, but those papers did not examine any patterns in those removals that might be present. Analysis of the tooth avulsions at Roonka reveals a change in the practice over time, with the older burials from phase II typically showing removal of both maxillary central incisors with a left side bias when only one tooth is removed, and the more recent phase III burials showing only one incisor avulsed and a right side bias for removal. Frequencies in the practice also changed over time, with avulsions being much more common in the older phase II burials. Historical evidence suggests that any particular regional or social group would have its own particular pattern of tooth avulsion, so these changes in tooth avulsions at Roonka suggest that the site was either used by multiple groups of people for burials, or that there was significant cultural change during the occupation of the site. Am J Phys Anthropol 154:479–485, 2014. © 2014 Wiley Periodicals, Inc.
Organozinn(IV)‐beladenes mesoporöses SiO2 als biokompatible Strategie bei der Krebstherapie
Authors: Bulatović Mirna Z. , Maksimović‐Ivanić Danijela , Bensing Christian , Gómez‐Ruiz Santiago , Steinborn Dirk , Schmidt Harry , Mojić Marija , Korać Aleksandra , Golić Igor , Pérez‐Quintanilla Damian , Momčilović Miljana , Mijatović Sanja , Kaluđerović Goran N.
Published: May 2014

Das große therapeutische Potenzial eines Organozinn(IV)‐beladenen nanostrukturierten SiO2 (SBA‐15pSn) wird am Beispiel der Rückbildung eines durch B16‐Zellen induzierten Melanoms bei syngenen C57BL/6‐Mäusen demonstriert. Neben Apoptose als grundlegendem Mechanismus der Antitumorwirkung einer Vielzahl von Chemotherapeutika ist der entscheidende Vorteil dieses mesoporösen zinnhaltigen Materials das Auslösen der Zelldifferenzierung – ein Effekt, der weder für metallbasierte Zytostatika noch für mesoporöse Materialien alleine bisher beobachtet wurde. Dieser nichtaggressive Wirkungsmechanismus ist hochwirksam gegen Tumorzellen aber im gewählten Konzentrationsbereich nichttoxisch für normales Gewebe. JNK‐unabhängige Apoptose (JNK: Jun amino‐terminal kinase), begleitet von der Bildung des melanozytenartigen nichtproliferativen Phänotyps der überlebenden Zellen demonstriert das außergewöhnliche Potenzial von SBA‐15pSn zur Unterdrückung von Tumorwachstum ohne eine unerwünschte kompensatorische Proliferation der erkrankten Zellen als Antwort auf den Zelltod in ihrer Nachbarschaft.
Organotin(IV)‐Loaded Mesoporous Silica as a Biocompatible Strategy in Cancer Treatment
Authors: Bulatović Mirna Z. , Maksimović‐Ivanić Danijela , Bensing Christian , Gómez‐Ruiz Santiago , Steinborn Dirk , Schmidt Harry , Mojić Marija , Korać Aleksandra , Golić Igor , Pérez‐Quintanilla Damian , Momčilović Miljana , Mijatović Sanja , Kaluđerović Goran N.
Published: May 2014

The strong therapeutic potential of an organotin(IV) compound loaded in nanostructured silica (SBA‐15pSn) is demonstrated: B16 melanoma tumor growth in syngeneic C57BL/6 mice is almost completely abolished. In contrast to apoptosis as the basic mechanism of the anticancer action of numerous chemotherapeutics, the important advantage of this SBA‐15pSn mesoporous material is the induction of cell differentiation, an effect unknown for metal‐based drugs and nanomaterials alone. This non‐aggressive mode of drug action is highly efficient against cancer cells but is in the concentration range used nontoxic for normal tissue. JNK (Jun‐amino‐terminal kinase)‐independent apoptosis accompanied by the development of the melanocyte‐like nonproliferative phenotype of survived cells indicates the extraordinary potential of SBA‐15pSn to suppress tumor growth without undesirable compensatory proliferation of malignant cells in response to neighboring cell death.
Copper‐Catalyzed Aerobic Oxidative CC Bond Cleavage for CN Bond Formation: From Ketones to Amides
Authors: Tang Conghui , Jiao Ning
Published: May 2014

A novel copper‐catalyzed aerobic oxidative C(CO)C(alkyl) bond cleavage reaction of aryl alkyl ketones for CN bond formation is described. A series of acetophenone derivatives as well as more challenging aryl ketones with long‐chain alkyl substituents could be selectively cleaved and converted into the corresponding amides, which are frequently found in biologically active compounds and pharmaceuticals.
Evaluation of optimal operation alternatives of reactors used for d‐glucose oxidation in a bi‐enzymatic system with a complex deactivation kinetics
Authors: Maria Gheorghe , Crisan Mara
Published: May 2014

One essential engineering problem when developing an industrial enzymatic process concerns the choice of the reactor alternative based on a priori knowledge on process and (free vs immobilized) enzyme characteristics, materials, and operation costs. For a multi‐enzymatic system, involving complex interactions among enzymes that exhibit optimal activity on different parametric domains and a high‐order deactivation, this problem requires an extended analysis. The study aims at extending the use of a modular simulation platform by approaching the optimization of complex multi‐enzymatic systems. An optimal constructive and operating alternative is determined for the case study of the complex oxidation of d‐glucose to 2‐keto‐d‐glucose in the presence of oxygen 2‐oxidoreductase (P2Ox, EC 1.1.3.10) and catalase (EC 1.11.1.6), by comparatively analyzing various enzymatic reactor models (simple batch, batch with intermittent addition of enzyme, semi‐batch reactor, continuously operated packed‐bed column, or mechanically agitated reactor with enzyme immobilized on support). Optimal reactor choice is based on the minimum amount of required P2Ox that ensures an imposed reaction conversion and reactor productivity under various technological constraints, by testing two temperatures (25 and 30 °C) and various catalase/P2Ox ratios (0–300/1 U U−1). © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Nylon 6/multiwalled carbon nanotube composites: Effect of the melt‐compounding conditions and nanotube content on the morphology, mechanical properties, and rheology
Authors: Puch Florian , Hopmann Christian
Published: May 2014

The effect of the melt‐compounding conditions with the use of a corotating intermeshing twin‐screw extruder and of the nanotube content on the morphology and the mechanical and rheological properties of nylon 6/multiwalled carbon nanotube (MWCNT) composites was investigated. The melt‐compounding conditions affected the morphology, but the variations in the morphology did not necessarily result in substantial variations in the mechanical and rheological properties. The mass throughput had the strongest influence on the mechanical properties, whereas the MWCNT feeding substantially affected the rheology. The increase in the MWCNT volume content from 0.0 to 3.5 vol % led to an increase in the Young's modulus, whereas the tensile strength, elongation at break, and notched impact strength exhibited maximum values around 0.5 to 1.0 vol %. With increasing MWCNT volume contents, higher complex viscosities and storage and loss moduli and a lower loss factor compared to neat nylon 6 were observed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40893.
Polyurethane electrospun mats strengthened and toughened by physically blended polyhedral oligomeric silsesquioxane
Authors: Hao Wentao , Fang Caiping , Yu Jixian , Zhang Liang , Xue Teng , Yang Wen
Published: May 2014

In this work, polyfunctional polyhedral oligomeric silsesquioxane (POSS) with glycidyl ether groups was physically blended with end‐capped polyurethane (PU) to improve the mechanical strength of PU electrospun mats. It was found that not only the tensile strength was elevated, but also the elongation‐at‐break was greatly improved. Fourier transform infrared spectroscopy results suggested that no chemical reaction happened, and there was no hydrogen bonding between POSS and PU, but the mobility of the PU chains was restricted. Wide‐angle X‐ray diffraction patterns showed that POSS aggregated inside the PU electrospun fibers. Scanning electron microscopy observation showed apparent die‐swelling, indicating that the elasticity of PU chains was enhanced. This was always the result of strengthened chain–chain interactions. From the experimental observations, it was speculated that a physical polymer–particle network was established through attachment of PU chains onto the POSS nanoparticles and embedment of PU chains inside the POSS aggregates, which results in the simultaneous improvements in strength and extensibility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40902.
Nonlinear optical materials by electrospinning technique
Authors: De Matteis Fabio , Fanicchia Francesco , Lamastra Francesca Romana , Stracci Glauco , De Angelis Roberta , Prosposito Paolo , Nanni Francesca , Casalboni Mauro
Published: May 2014

The possibility of using electrospinning to deposit, and simultaneously electrically pole, polymeric mats containing nonlinear optical (NLO) molecules is studied. Disperse Red 1 (DR1) chromophore dispersed into polymethyl methacrylate (PMMA) fibers is chosen as test system. Aligned fibers of DR1/PMMA are deposited by means of the rotating collector electrospinning technique. The processing parameters are optimized to obtain an oriented texture of fibers and the NLO activity is characterized by means of second harmonic generation measurements. Comparison with spin coating and corona poling samples of the same material is discussed. The results point toward a low efficiency of chromophore orientation for the electrospun samples in comparison to the poled ones. An improvement in the electrospinning apparatus is proposed to enhance the chromophore orientation in the polymeric fibers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40913.
Student failures on first‐year medical basic science courses and the USMLE step 1: A retrospective study over a 20‐year period
Authors: Burns E. Robert , Garrett Judy
Published: May 2014

Correlates of achievement in the basic science years in medical school and on the Step 1 of the United States Medical Licensing Examination® (USMLE®), (Step 1) in relation to preadmission variables have been the subject of considerable study. Preadmissions variables such as the undergraduate grade point average (uGPA) and Medical College Admission Test® (MCAT®) scores, solely or in combination, have previously been found to be predictors of achievement in the basic science years and/or on the Step 1. The purposes of this retrospective study were to: (1) determine if our statistical analysis confirmed previously published relationships between preadmission variables (MCAT, uGPA, and applicant pool size), and (2) study correlates of the number of failures in five M1 courses with those preadmission variables and failures on Step 1. Statistical analysis confirmed previously published relationships between all preadmission variables. Only one course, Microscopic Anatomy, demonstrated significant correlations with all variables studied including the Step 1 failures. Physiology correlated with three of the four variables studied, but not with the Step 1 failures. Analyses such as these provide a tool by which administrators will be able to identify what courses are or are not responding in appropriate ways to changes in the preadmissions variables that signal student performance on the Step 1. Anat Sci Educ 8: 120–125. © 2014 American Association of Anatomists.
Chemical Constituents from the Heartwood of Haematoxylon campechianum as Protein Tyrosine Kinase Inhibitors
Authors: Lin Li‐Gen , Xie Hua , Wang Yi‐Tao , Ding Jian , Ye Yang
Published: May 2014

In a previous study, we showed that a series of homoisoflavonoids from the stems of Haematoxylon campechianum possess potent protein tyrosine kinase inhibitory activity. In a further chemical investigation of the heartwood of H. campechianum, three new homoisoflavonoids, epihematoxylol B (2), 10‐O‐methylhematoxylol B (3), and 10‐O‐methylepihematoxylol B (4), were isolated and identified, together with 15 known compounds, including three homoisoflavonoids, three flavonoids, six lignans, and three unsaturated fatty acids. The structures of the new compounds were established on the basis of 1D‐ and 2D‐NMR and other spectroscopic analyses.
Design and Synthesis of Fmoc‐Thr[PO(OH)(OPOM)] for the Preparation of Peptide Prodrugs Containing Phosphothreonine in Fully Protected Form
Authors: Qian Wen‐Jian , Lai Christopher C. , Kelley James A. , Burke Terrence R.
Published: May 2014

The design and efficient synthesis of N‐Fmoc‐phosphothreonine protected by a mono‐(pivaloyloxy)methyl (POM) moiety at its phosphoryl group (Fmoc‐Thr[PO(OH)(OPOM)]‐OH, 1, is reported. This reagent is suitable for solid‐phase syntheses employing acid‐labile resins and Fmoc‐based protocols. It allows the preparation of phosphothreonine (pThr)‐containing peptides bearing bis‐POM‐phosphoryl protection. The methodology allows the first reported synthesis of pThr‐containing polypeptides having bioreversible prodrug protection, and as such it should be useful in a variety of biological applications.
Antifungal Bromophenols from Marine Red Alga Symphyocladia latiuscula
Authors: Xu Xiuli , Yin Liyuan , Gao Junhai , Gao Lijie , Song Fuhang
Published: May 2014

Three new highly brominated polyphenols, 1–3, together with one known bromophenol, 4, were isolated from the EtOH extract of a marine red alga Symphyocladia latiuscula collected from the coast of Qingdao, P. R. China. Their structures were identified by extensive spectroscopic experiments (NMR and MS) and comparison with literature data. Compounds 3 and 4 showed activities against the Candida albicans with the MIC values of 25 and 12.5 μg/ml, respectively.
Application of Two‐Way Hierarchical Cluster Analysis for the Identification of Similarities between the Individual Lipid Fractions of Lucilia sericata
Authors: Gołębiowski Marek , Sosnowska Anita , Puzyn Tomasz , Boguś Mieczysława I. , Wieloch Wioletta , Włóka Emilia , Stepnowski Piotr
Published: May 2014

The composition of the cuticular and internal lipids of larvae and pupae of Lucilia sericata was studied using chromatographic techniques. The lipids from both stages of L. sericata had similar free fatty acid (FFA) profiles and also contained alcohols and cholesterol. The range of the number of C‐atoms detected for these classes of compounds was to some extent similar in larvae and pupae, but the relative amounts of each class differed between stages. Saturated as well as unsaturated FFAs with even and odd numbered C‐atom chains were present in both cuticular and internal lipids. The alcohol fractions of L. sericata were represented by free, straight‐chain primary alcohols containing an even number of C‐atoms. The lipid composition of male and female L. sericata adults and the hydrocarbon composition of all stages of L. sericata had previously been analyzed. To have a full overview of the lipid composition and to identify similarities or dissimilarities between the individual lipid fractions in this insect species, two‐way hierarchical cluster analysis (HCA) was performed using also the data from these previous publications. The content of FFA 18 : 1 (n‐9) was noticed to be very high in the cuticular fractions of larvae and pupae as well as in all internal fractions (male, female, larvae, and pupae) and low in the cuticular fractions of male and female imago. The contents of FFAs 16 : 0 and 16 : 1 (n‐9), cholesterol, and the n‐alkanes n‐C31, n‐C29, n‐C27, n‐C25, and n‐C23 varied between particular fractions, whereas the amounts of other compounds were similar in all fractions.
Suppression of Inducible Nitric Oxide Synthase Expression by Nyasol and Broussonin A, Two Phenolic Compounds from Anemarrhena asphodeloides, through NF‐κB Transcriptional Regulation in vitro and in vivo
Authors: Jin Lee Eun , Chung Hwa‐Jin , Pyee Yuna , Hong Ji‐Young , Joung Youn Ui , Seo Eun‐Kyoung , Kook Lee Sang
Published: May 2014

Anemarrhena asphodeloides is widely used in traditional Chinese medicine, and is known to possess antidiabetic and anti‐inflammatory properties. Because inducible nitric oxide synthase (iNOS) plays an important role in inflammation, we investigated the inhibitory effects of two known phenolic compounds, nyasol (1) and broussonin A (2), from A. asphodeloides, on iNOS and its plausible mechanism of action. Compounds 1 and 2 exhibited inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells. Compounds 1 and 2 also suppressed the expressions of iNOS protein and mRNA. Moreover, compounds 1 and 2 suppressed the expression of inflammatory cytokines such as interleukin‐1β (IL‐1β) and interferon‐β (IFN‐β). They also inhibited the transcriptional activity of NF‐κB and degradation of IκB‐α, as well as the activation of Akt and ERK in LPS‐stimulated RAW 264.7 cells. In in vivo animal model, compounds 1 and 2 significantly inhibited TPA‐induced mouse ear edema. These results suggest that 1 and 2 suppress LPS‐stimulated iNOS expression at the transcriptional level through modulating NF‐κB and down‐regulation of the Akt and ERK signaling pathways. Taken together, these findings indicate that the suppressive effects of 1 and 2 on iNOS expression might provide one possible mechanism for their anti‐inflammatory activities.
Fluorescent Visualization of Src by Using Dasatinib‐BODIPY
Authors: Vetter Michael L. , Zhang Zijuan , Liu Shuai , Wang Jinhua , Cho HaeYeon , Zhang Jianming , Zhang Wei , Gray Nathanael S. , Yang Priscilla L.
Published: May 2014

Many biological experiments are not compatible with the use of immunofluorescence, genetically encoded fluorescent tags, or FRET‐based reporters. Conjugation of existing kinase inhibitors to cell‐permeable fluorophores can provide a generalized approach to develop fluorescent probes of intracellular kinases. Here, we report the development of a small molecule probe of Src through conjugation of BODIPY to two well‐established dual Src‐Abl kinase inhibitors, dasatinib and saracatinib. We show that this approach is not successful for saracatinib but that dasatinib‐BODIPY largely retains the biological activity of its parent compound and can be used to monitor the presence of Src kinase in individual cells by flow cytometry. It can also be used to track the localization of Src by fixed and live‐cell fluorescence microscopy. This strategy could enable generation of additional kinase‐specific probes useful in systems not amenable to genetic manipulation or could be used together with fluorescent proteins to enable a multiplexed assay readout.
One‐year follow‐up of patients treated with new‐generation polymer‐based 38 mm everolimus‐eluting stent: The P38 study
Authors: Sgueglia Gregory A. , Belloni Flavia , Summaria Francesco , Conte Micaela , Cortese Bernardo , Silva Pedro Leon , Ricci Roberto , Lioy Ernesto , Pucci Edoardo , Gaspardone Achille
Published: May 2014

Objectives

To assess the clinical outcome at 1‐year follow‐up of real‐world patients with long coronary lesions treated with the 38 mm Xience Prime (Abbott Vascular) everolimus‐eluting stent (EES).

Background

Long‐lesions present special challenges to the interventional cardiologists, including increased risk of restenosis, periprocedural injury, geographical miss, and stent deliverability. Indeed, results obtained with shorter stent in the treatment of simpler lesions are of limited applicability to longer stents.

Methods

Consecutive patients presenting with a long coronary lesion treated by percutaneous coronary intervention with at least one implanted 38 mm EES were enrolled in the study. Their clinical data were prospectively registered. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, nonfatal myocardial infarction (according to the Universal Definition) and target vessel revascularization. Stent thrombosis was defined according to the Academic Research Consortium criteria.

Results

Overall, 203 real‐world patients (152 men, 68 ± 9 years) were enrolled in the P38 Study. At 1‐year follow‐up, 6 (3.0%) patients had died from cardiac causes, 7 (3.4%) had a nonfatal myocardial infarction and 8 (3.9%) underwent target vessel revascularization, yielding a 10.3% cumulative rate of MACE. Two patients had a stent thrombosis (one definite and one probable). No significant differences in event rates were found between patients with and without an additional stent implanted overlapping the 38 mm one.

Conclusions

The use of a new‐generation polymer‐based 38 mm EES in a real‐world population with unselected long lesions is associated with excellent procedural results and good clinical outcomes at 12‐month follow‐up. © 2014 Wiley Periodicals, Inc.
Initial experience with the cook formula balloon expandable stent in congenital heart disease
Authors: Quandt Daniel , Ramchandani Bharat , Bhole Vinay , Penford Gemma , Mehta Chetan , Dhillon Rami , Stumper Oliver
Published: May 2014

Introduction

Balloon expandable stents are an integral part in the catheter treatment of congenital heart disease. In the growing child, stents require dilatation to greater diameters over time. The Cook Formula stent is a recent 316 stainless steel open‐cell design licensed for peripheral vascular work.

Methods

Following extensive ex vivo studies, 112 stents were implanted in 97 children [median age 3.9 (0.01–17.6) years; median weight 13.7 (2.4–62.8) kg] over a 27‐month (Oct 2011–Dec 2013) period.

Results

Bench testing revealed that there was no stent shortening for dilatation to nominal diameter and beyond. The 5 mm stents could be dilated up to 10 mm, and the 10 mm stents to 20 mm. Stents were implanted through 4–7F sheaths or guide catheters over appropriate wires. Stent tracking and delivery was excellent. Twenty‐three stents were implanted in the right ventricular outflow tract in Fallot‐type lesions, 53 for branch pulmonary artery stenosis (22 post cavopulmonary shunt/Fontan), 14 conduit stenosis, 13 Fontan fenestrations, 3 PDA in hybrid stage I Norwood, 5 in coarctation, and 1 for SVC obstruction. Sixty‐one stents (54%) were overdilated. There were no stent fractures. Radial strength was very good, whereas stent conformability was limited.

Conclusions

The Cook Formula stent is a premounted balloon‐expandable stent that can be significantly overdilated with virtually no shortening allowing for precise placement and minimal protrusion into adjacent vessels. The Formula stent is a very versatile addition to the range of stents for use in the catheter treatment of complex congenital heart disease in children. © 2014 Wiley Periodicals, Inc.