bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Single Deformed Bow Shock for Titan‐Saturn System
Authors: Omidi N. , Sulaiman A. H. , Kurth W. , Madanian H. , Cravens T. , Sergis N. , Dougherty M. K. , Edberg N. J. T. 
Published: October 2017

AbstractDuring periods of high solar wind pressure, Saturn's bow shock is pushed inside Titan's orbit exposing the moon and its ionosphere to the solar wind. The Cassini spacecraft's T96 encounter with Titan occurred during such a period and showed evidence for shocks associated with Saturn and Titan. It also revealed the presence of two foreshocks: one prior to the closest approach (foreshock 1) and one after (foreshock 2). Using electromagnetic hybrid (kinetic ions and fluid electrons) simulations and Cassini observations, we show that the origin of foreshock 1 is tied to the formation of a single deformed bow shock for the Titan‐Saturn system. We also report the observations of a structure in foreshock 1 with properties consistent with those of spontaneous hot flow anomalies formed in the simulations and previously observed at Earth, Venus, and Mars. The results of hybrid simulations also show the generation of oblique fast magnetosonic waves upstream of the outbound Titan bow shock in agreement with the observations of large‐amplitude magnetosonic pulsations in foreshock 2. We also discuss the implications of a single deformed bow shock for new particle acceleration mechanisms and also Saturn's magnetopause and magnetosphere.
Crustal Thickness Beneath Libya and the Origin of Partial Melt Beneath AS Sawda Volcanic Province From Receiver Function Constraints
Authors: Lemnifi Awad A. , Elshaafi Abdelsalam , Browning John , Aouad Nassib S. , El Ebaidi Saad K. , Liu Kelly K. , Gudmundsson Agust 
Published: October 2017

AbstractThis study investigates crustal thickness and properties within the Libyan region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions. The results show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from 32 km to 36 km in the southern portion of the Libyan territory then becomes thinner, between 24 km and 30 km, in the coastal areas of Libya and thinnest, between 24 km and 28 km, in the Sirt Basin. The observed high Vp/Vs value of 1.91 at one station located at the AS Sawda Volcanic Province in central Libya indicates the presence of either partial melt or an abnormally warm area. This finding suggests that magma reservoirs beneath the Libyan territory may still be partially molten and active, thereby posing significant earthquake and volcanic risks. The hypothesis of an active magma source is further demonstrated though the presence of asthenospheric upwelling and extension of the Sirt Basin. This study provides a new calculation of unconsolidated sediment layers by using the arrival time of the P to S converted phases. The results show sediments thicknesses of 0.4 km to 3.7 km, with the Vp/Vs values ranging from 2.2 to 4.8. The variations in crustal thickness throughout the region are correlated with surface elevation and Bouguer gravity anomalies, which suggest that they are isostatically compensated.
Pressure‐Dependent Elastic and Transport Properties of Porous and Permeable Rocks: Microstructural Control
Authors: Pimienta Lucas , Sarout Joel , Esteban Lionel , David Christian , Clennell Michael B. 
Published: October 2017

AbstractAlthough several studies aimed at linking electrical and hydraulic transport properties in rocks, the existing models remain at most incomplete. Based on this observation, in addition to the transport properties, this contribution investigates the pressure dependence of P wave velocities and porosity for three porous rocks. Apart from hydraulic conductivity, all physical properties show an important dependence to the confining pressure. In particular, electrical resistivity reaches an asymptote at low confining pressures. Using the measured P wave velocities and effective medium theories, the microcrack density (ρ) and its evolution with confining pressure are estimated. For the three rocks, the microcrack density at which electrical resistivity reaches a plateau is of ρ ~0.13. This value corresponds to the threshold for crack percolation in media containing microcracks exclusively. This suggests that in porous and microcracked rocks, electrical resistivity is controlled by two independent hydraulic pathways of tubes and cracks acting in parallel. In contrast, this percolation threshold is not observed in the permeability data. A simple conceptual model is finally introduced that explains the fundamental differences between transport properties.
A Model and Satellite‐Based Analysis of the Tropospheric Ozone Distribution in Clear Versus Convectively Cloudy Conditions
Authors: Strode Sarah A. , Douglass Anne R. , Ziemke Jerald R. , Manyin Michael , Nielsen J. Eric , Oman Luke D. 
Published: October 2017

AbstractSatellite observations of in‐cloud ozone concentrations from the Ozone Monitoring Instrument and Microwave Limb Sounder instruments show substantial differences from background ozone concentrations. We develop a method for comparing a free‐running chemistry‐climate model (CCM) to in‐cloud and background ozone observations using a simple criterion based on cloud fraction to separate cloudy and clear‐sky days. We demonstrate that the CCM simulates key features of the in‐cloud versus background ozone differences and of the geographic distribution of in‐cloud ozone. Since the agreement is not dependent on matching the meteorological conditions of a specific day, this is a promising method for diagnosing how accurately CCMs represent the relationships between ozone and clouds, including the lower ozone concentrations shown by in‐cloud satellite observations. Since clouds are associated with convection as well as changes in chemistry, we diagnose the tendency of tropical ozone at 400 hPa due to chemistry, convection and turbulence, and large‐scale dynamics. While convection acts to reduce ozone concentrations at 400 hPa throughout much of the tropics, it has the opposite effect over highly polluted regions of South and East Asia.
Relationships Between Gravity Waves Observed at Earth's Surface and in the Stratosphere Over the Central and Eastern United States
Authors: de Groot‐Hedlin Catherine D. , Hedlin Michael A. H. , Hoffmann Lars , Alexander M. Joan , Stephan Claudia C. 
Published: October 2017

AbstractObservations of tropospheric gravity waves (GWs) made by the new and extensive USArray Transportable Array (TA) barometric network located east of the Rockies, in the central and eastern United States and of stratospheric (30–40 km above sea level) GWs made by the Atmospheric Infrared Sounder (AIRS) are compared over a 5 year time span from 2010 through 2014. GW detections in the period band from 2 to 6 h made at the Earth's surface during the thunderstorm season from May through August each year exhibit the same broad spatial and temporal patterns as observed at stratospheric altitudes. At both levels, the occurrence frequency of GWs is higher at night than during the day and is highest to the west of the Great Lakes. Statistically significant correlations between the variance of the pressure at the TA, which is a proxy for GWs at ground level, with 8.1 μm brightness temperature measurements from AIRS and rain radar precipitation data, which are both proxies for convective activity, indicate that GWs observed at the TA are related to convective sources. There is little, if any, time lag between the two. Correlations between GWs in the stratosphere and at ground level are weaker, possibly due to the AIRS observational filter effect, but are still statistically significant at nighttime. We conclude that convective activity to the west of the Great Lakes is the dominant source of GWs both at ground level and within the stratosphere.
Molecular Halogens Above the Arctic Snowpack: Emissions, Diurnal Variations, and Recycling Mechanisms
Authors: Wang Siyuan , Pratt Kerri A. 
Published: October 2017

AbstractElevated levels of reactive bromine and chlorine species in the springtime Arctic boundary layer contribute to ozone depletion and mercury oxidation, as well as reactions with volatile organic compounds. Recent laboratory and field studies have revealed that snowpack photochemistry leads to Br2 and Cl2 production, the mechanisms of which remain poorly understood. In this work, we use a photochemical box model, with a simplified snow module, to examine the halogen chemistry occurring during the March 2012 Bromine, Ozone, and Mercury Experiment (BROMEX) near Utqiaġvik (Barrow), Alaska. Elevated daytime Br2 levels (e.g., 6–30 parts per trillion (ppt) at around local noon) reported in previous studies and in this work may be explained by Br + BrNO2/BrONO2 reactions under conditions of depleted O3 (<~10 ppb) and background NO2 (10–100 ppt). Even at low background NOx levels at Utqiaġvik, ClONO2 is predicted to be important in the production of Cl2 via multiphase reaction with Cl−. In the late afternoon, photolysis alone cannot explain the rapid decrease of Cl2 observed in the Arctic boundary layer. Heterogeneous reactions of Cl2 on aerosol particles and surface snowpack are suggested to play a key role in atmospheric Cl2 removal and possible BrCl production. Given the importance of the snowpack in the multiphase chemistry of the Arctic boundary layer, future measurements should focus on vertically resolved measurements of NOx and reactive halogens, as well as simultaneous particulate and snow halide measurements, to further evaluate and isolate the halogen production and vertical propagation mechanisms through one‐dimensional modeling.
Sources and Potential Photochemical Roles of Formaldehyde in an Urban Atmosphere in South China
Authors: Wang Chuan , Huang Xiao‐Feng , Han Yu , Zhu Bo , He Ling‐Yan 
Published: October 2017

AbstractFormaldehyde (HCHO) is an important intermediate in tropospheric photochemistry. However, study of its evolution characteristics under heavy pollution conditions in China is limited, especially for high temporal resolutions, making it difficult to analyze its sources and environmental impacts. In this study, ambient levels of HCHO were monitored using a proton‐transfer reaction mass spectrometer at an urban site in the Pearl River Delta of China. Continuous monitoring campaigns were conducted in the spring, summer, fall, and winter in 2016. The highest averaged HCHO concentrations were observed in autumn (5.1 ± 3.1 ppbv) and summer (5.0 ± 4.4 ppbv), followed by winter (4.2 ± 2.2 ppbv) and spring (3.4 ± 1.6 ppbv). The daily maximum of HCHO occurs in the early afternoon and shows good correlations with O3 and the secondary organic aerosol tracer during the day, revealing close relationships between ambient HCHO and secondary formations in Shenzhen, especially in summer and autumn. The daytime HCHO is estimated to be the major contributor to O3 formation and OH radical production, indicating that HCHO plays a key role in the urban atmospheric photochemical reactions. Anthropogenic secondary formation was calculated to be the dominant source of HCHO using a photochemical age‐based parameterization method, with an average proportion of 39%. The contributions of biogenic sources in summer (41%) and autumn (39%) are much higher than those in spring (26%) and winter (28%), while the contributions of anthropogenic primary sources in spring (20%) and winter (18%) are twice those in summer (9%) and autumn (9%).
Improving Lightning and Precipitation Prediction of Severe Convection Using Lightning Data Assimilation With NCAR WRF‐RTFDDA
Authors: Wang Haoliang , Liu Yubao , Cheng William Y. Y. , Zhao Tianliang , Xu Mei , Liu Yuewei , Shen Si , Calhoun Kristin M. , Fierro Alexandre O. 
Published: October 2017

AbstractIn this study, a lightning data assimilation (LDA) scheme was developed and implemented in the National Center for Atmospheric Research Weather Research and Forecasting‐Real‐Time Four‐Dimensional Data Assimilation system. In this LDA method, graupel mixing ratio (qg) is retrieved from observed total lightning. To retrieve qg on model grid boxes, column‐integrated graupel mass is first calculated using an observation‐based linear formula between graupel mass and total lightning rate. Then the graupel mass is distributed vertically according to the empirical qg vertical profiles constructed from model simulations. Finally, a horizontal spread method is utilized to consider the existence of graupel in the adjacent regions of the lightning initiation locations. Based on the retrieved qg fields, latent heat is adjusted to account for the latent heat releases associated with the formation of the retrieved graupel and to promote convection at the observed lightning locations, which is conceptually similar to the method developed by Fierro et al. Three severe convection cases were studied to evaluate the LDA scheme for short‐term (0–6 h) lightning and precipitation forecasts. The simulation results demonstrated that the LDA was effective in improving the short‐term lightning and precipitation forecasts by improving the model simulation of the qg fields, updrafts, cold pool, and front locations. The improvements were most notable in the first 2 h, indicating a highly desired benefit of the LDA in lightning and convective precipitation nowcasting (0–2 h) applications.
Lateral hypothalamic activity indicates hunger and satiety states in humans
Authors: Talakoub Omid , Paiva Raquel R. , Milosevic Matija , Hoexter Marcelo Q. , Franco Ruth , Alho Eduardo , Navarro Jessie , Pereira José F. , Popovic Milos R. , Savage Cary , Lopes Antonio C. , Alvarenga Pedro , Damiani Durval , Teixeira Manoel J. , Miguel Euripides C. , Fonoff Erich T. , Batistuzzo Marcelo C. , Hamani Clement 
Published: October 2017

AbstractLateral hypothalamic area (LHA) local field potentials (LFPs) were recorded in a Prader–Willi patient undergoing deep brain stimulation (DBS) for obesity. During hunger, exposure to food‐related cues induced an increase in beta/low‐gamma activity. In contrast, recordings during satiety were marked by prominent alpha rhythms. Based on these findings, we have delivered alpha‐frequency DBS prior to and during food intake. Despite reporting an early sensation of fullness, the patient continued to crave food. This suggests that the pattern of activity in LHA may indicate hunger/satiety states in humans but attest to the complexity of conducting neuromodulation studies in obesity.
Synthesis of Diverse Nitrogen Heterocycles via Palladium‐Catalyzed Tandem Azide–Isocyanide Cross‐Coupling/Cyclization: Mechanistic Insight using Experimental and Theoretical Studies
Authors: Ansari Arshad J. , Pathare Ramdas S. , Maurya Antim K. , Agnihotri Vijai K. , Khan Shahnawaz , Roy Tapta Kanchan , Sawant Devesh M. , Pardasani Ram T. 
Published: October 2017

AbstractA rapid and elegant tandem azide–isocyanide cross‐coupling/cyclization protocol has been developed based on a nitrene transfer reaction. The palladium‐catalyzed ligand‐free methodology led to the synthesis of three different heterocyclic scaffolds with excellent atom/step/redox economy. Studies based on first‐principles‐based quantum calculations and control experiments unraveled a concerted process of nitrene transfer reaction on isocyanides, ruling out the metallaaziridine intermediate reported earlier. This finding could pave the way for novel applications of nitrene transfer reactions to generate bioactive heterocycles.magnified image
Asymmetric 1,6‐Conjugate Addition of para‐Quinone Methides for the Synthesis of Chiral β,β‐Diaryl‐α‐Hydroxy Ketones
Authors: Gao Yuan‐Yuan , Hua Yuan‐Zhao , Wang Min‐Can 
Published: October 2017

AbstractA direct asymmetric 1,6‐conjugated addition of α‐hydroxy ketone to para‐quinone methides has been developed. It is an efficient approach to the synthesis of chiral β,β‐diaryl‐α‐hydroxy ketones. The reaction runs smoothly in the presence of ZnEt2 and nonracemic bis(diarylhydroxymethylpyrrolidinylmethyl)phenols (ProPhenols), and the desired products are obtained in good yields (up to 88%) and with high stereoselectivity (up to >99% ee and up to >99:1 dr). This reaction also can be run on a gram scale without impacting its enantioselectivity.magnified image
Iodine‐Catalyzed Synthesis of Chalcogenophenes by the Reaction of 1,3‐Dienyl Bromides and Potassium Selenocyanate/Potassium Sulfide (KSeCN/K2S)
Authors: Maity Pintu , Ranu Brindaban C. 
Published: October 2017

AbstractThe methods available for the synthesis of chalcogenophenes, in general, are associated with drawbacks of harsh conditions, use of costly metals, broad applicability, tedious purification process and low yield. To avoid these drawbacks a transition metal‐free iodine‐catalyzed reaction of aryl‐susbstituted 1,3‐dienyl bromides with potassium selenocyanate/potassium sulfide (KSeCN/K2S) leading to the corresponding selenophenes and thiophenes has been developed. Iodine is relatively benign, less expensive and readily available. Several diversely substituted selenophenes and thiophenes have been obtained by this procedure in high yields. Using this procedure 2‐(4‐chlorophenyl)thiophene, a key intermediate for the synthesis of a melanin concentrating hormone receptor ligand involved in the treatment of eating disorders, weight gain, obesity, depression and anxiety has been synthesized. Although the reaction is one‐pot essentially it proceeds in two steps involving a selenocyanate/thiolate intermediate leading to the selenophene/thiophene. The simple operation, use of inexpensive reagents and a metal‐free process make this procedure more attractive for an easy access to substituted selenophenes and thiophenes.magnified image
Ester Synthesis in Water: Mycobacterium smegmatis Acyl Transferase for Kinetic Resolutions
Authors: de Leeuw Nicolas , Torrelo Guzman , Bisterfeld Carolin , Resch Verena , Mestrom Luuk , Straulino Emanuele , van der Weel Laura , Hanefeld Ulf 
Published: October 2017

AbstractThe acyl transferase from Mycobacterium smegmatis (MsAcT) catalyses transesterification reactions in aqueous media because of its hydrophobic active site. Aliphatic cyanohydrin and alkyne esters can be synthesised in water with excellent and strikingly opposite enantioselectivity [(R);E>37 and (S);E>100, respectively]. When using this enzyme, the undesired hydrolysis of the acyl donor is an important factor to take into account. Finally, the choice of acyl donor can significantly influence the obtained enantiomeric excesses.magnified image
Coin pica‐induced gastric perforation resulting from ingestion of 1,894 coins, 8 kg in total: case report and review of published works
Authors: Sekiya Kosuke , Mori Shusuke , Otomo Yasuhiro 
Published: October 2017

CasePica is common among patients with psychiatric disorders, but only a few cases regarding coin pica have been reported. A 51‐year‐old man with depression complaining of fatigue was found to have numerous coins in the esophagus and the stomach on X‐rays. He had a peritoneal sign and underwent an emergency laparotomy.OutcomeThe surgical findings showed perforation on the anterior wall of the gastric body and coins in the stomach, which were removed manually, followed by an omental patch. Residual coins in the esophagus were removed by endoscopy. The coins totaled 1,894, weighing 8,076 grams. The patient was then diagnosed as schizophrenic. He was asymptomatic for metal toxicity and was finally transferred to a psychiatric hospital.ConclusionThis pica case is the first to show coin pica can lead to gastric perforation, and also reports the largest amounts of coins ingested by a person to date.
Copper‐Catalyzed Synthesis of γ‐Amino Acids Featuring Quaternary Stereocenters
Authors: Gómez José Enrique , Guo Wusheng , Gaspa Silvia , Kleij Arjan W. 
Published: October 2017

AbstractThe first general asymmetric synthesis of γ,γ‐disubstituted γ‐amino acids by copper‐catalyzed ring opening of nonstrained lactones with amines is reported. This approach features ample scope, operational simplicity, and wide functional‐group diversity. The catalytic process allows access to a series of highly functionalized enantioenriched γ‐amino acids featuring quaternary stereocenters with excellent enantiomeric ratios of up to 98:2 and excellent yields of up to 98 %.
New alginate foams: Box‐Behnken design of their manufacturing; fire retardant and thermal insulating properties
Authors: Vincent Thierry , Dumazert Loïc , Dufourg Ludivine , Cucherat Claire , Sonnier Rodolphe , Guibal Eric 
Published: October 2017

ABSTRACTA new method for preparing alginate foams with progressive release of copper in the presence of sodium lauryl sulfate (SLS, foaming agent) has been designed. Copper acts as the ionotropic gelling agent through the reaction of copper carbonate with gluconolactone. The process does not require freeze‐drying contrarily to the conventional method used for preparing macroporous alginate foams. The new materials investigated in this study have remarkable thermal properties, including thermal conductivity lower than 0.041 W m−1 K−1 and low heat release (below 2 kJ g−1), which allows labeling these foams self‐extinguishing materials. An experimental design methodology, based on a Box‐Behnken plan with three parameters and three levels, is successfully used for evaluating the impact of the amounts of alginate, SLS, and copper carbonate on the productivity, apparent density, and shrinking at air‐drying. It yielded an optimization of the process for the manufacturing of light, and stable/rigid insulating and thermally stable materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45868.
The possible clinical impact of risperidone on P‐glycoprotein‐mediated transport of tacrolimus: A case report and in vitro study
Authors: Watanabe Nao , Higashi Hiroki , Nakamura Saki , Nomura Keiko , Adachi Yuichi , Taguchi Masato 
Published: October 2017

AbstractThe authors encountered the case of an 8‐fold increase in the concentration/dose (C/D) ratio of tacrolimus (TAC) following the coadministration of voriconazole (VRCZ) in a hematopoietic stem cell transplantation (HSCT) recipient. The interaction observed was much greater than expected and the patient had also been treated with oral risperidone (RSP). It was hypothesized that cytochrome P450 (CYP)3A inhibition of the small intestine by voriconazole and P‐glycoprotein (P‐gp) inhibition of the small intestine by risperidone exerted a synergistic effect on the bioavailability of tacrolimus. The aim of the present study was to evaluate the effect of risperidone on the P‐gp‐mediated transport of tacrolimus. The transcellular transport of P‐gp substrates was examined in Caco‐2 and P‐gp‐expressing renal epithelial LLC‐GA5‐COL150 cells. In Caco‐2 cells, the apical‐basal (A‐B) transport of rhodamine123 (Rh123) after a 120 min incubation was increased by 47.1%, whereas that in the B‐A direction was decreased by 61.7% in the presence of risperidone (100 μm). These results indicate that risperidone showed an inhibitory effect on the P‐gp‐mediated transport of Rh123. In LLC‐GA5‐COL150 cells, the A‐B transport of tacrolimus after 120 min incubation was increased by 21.7% in the presence of risperidone (100 μm), whereas that in the B‐A direction was decreased by 10.7%. These results suggest that risperidone was at least partly involved in the mechanism of the marked increase in the C/D ratio of tacrolimus. This case report provides new insights into the diversity of drug interactions of tacrolimus triggered by the combination of two concomitant drugs.