bluuebunny/crossref_metadata_2025 huggingface dataset:
Winter ocean‐ice interactions under thin sea ice observed by IAOOS platforms during N‐ICE2015: Salty surface mixed layer and active basal melt
Authors: Koenig Zoé , Provost Christine , Villacieros‐Robineau Nicolas , Sennéchael Nathalie , Meyer Amelie
Published: October 2016

IAOOS (Ice Atmosphere Arctic Ocean Observing System) platforms, measuring physical parameters at the atmosphere‐snow‐ice‐ocean interface deployed as part of the N‐ICE2015 campaign, provide new insights on winter conditions North of Svalbard. The three regions crossed during the drifts, the Nansen Basin, the Sofia Deep, and the Svalbard northern continental slope featured distinct hydrographic properties and ice‐ocean exchanges. In the Nansen Basin, the quiescent warm layer was capped by a stepped halocline (60 and 110 m) and a deep thermocline (110 m). Ice was forming and the winter mixed layer salinity was larger by ∼0.1 g/kg than previously observed. Over the Svalbard continental slope, the Atlantic Water (AW) was very shallow (20 m from the surface) and extended offshore from the 500 m isobath by a distance of about 70 km, sank along the slope (40 m from the surface) and probably shed eddies into the Sofia Deep. In the Sofia Deep, relatively warm waters of Atlantic origin extended from 90 m downward. Resulting from different pathways, these waters had a wide range of hydrographic characteristics. Sea‐ice melt was widespread over the Svalbard continental slope and ocean‐to‐ice heat fluxes reached values of 400 W m−2 (mean of ∼150 W m−2 over the continental slope). Sea‐ice melt events were associated with near 12 h fluctuations in the mixed‐layer temperature and salinity corresponding to the periodicity of tides and near‐inertial waves potentially generated by winter storms, large barotropic tides over steep topography, and/or geostrophic adjustments.
Anomalous diurnal variation of atmospheric potential gradient and air‐Earth current density observed at Maitri, Antarctica
Authors: Jeeva K. , Gurubaran S. , Williams E. R. , Kamra A. K. , Sinha A. K. , Guha A. , Selvaraj C. , Nair K. U. , Dhar Ajay
Published: October 2016

The scope of this paper is to explore the mechanisms operating over Maitri (70.76°S, 11.74°E, 117 m above mean sea level), a coastal Antarctic station, that produce an anomalous fair‐weather diurnal pattern of the atmospheric electric potential gradient (PG) and air‐Earth current density (AEC). The anomaly in the diurnal variations of AEC and the PG is displaying an ostensible minimum at ~10 UT and a diminished response to the thunderstorm over the African continent in the 14–16 UT time frame. The data sets (2005–2014, except 2012) of the PG, and to some extent, AEC, from Maitri, are used to explore this anomaly. It follows that the fair‐weather electrical phenomena over Maitri can be ascribed to global electrified convection on the one hand and to regional phenomena like convection due to the replacement of warm air by katabatic winds on the other hand. The katabatic winds originate on the polar plateau and blow from ~130° at Maitri which are likely to transport various elements from the mountain slopes, and space charge from the polar plateau is expected to produce various disturbances in the PG and AEC monitored over the coastal Antarctica. This mechanism may be responsible for peaks in the early UT hours and also for the anomalous behavior of atmospheric electrical parameters observed at Maitri. Maitri data are compared with that of Carnegie cruise and Vostok to explain the source of anomaly.
Land‐atmosphere coupling and climate prediction over the U.S. Southern Great Plains
Authors: Williams Ian N. , Lu Yaqiong , Kueppers Lara M. , Riley William J. , Biraud Sebastien C. , Bagley Justin E. , Torn Margaret S.
Published: October 2016

Biases in land‐atmosphere coupling in climate models can contribute to climate prediction biases, but land models are rarely evaluated in the context of this coupling. We tested land‐atmosphere coupling and explored effects of land surface parameterizations on climate prediction in a single‐column version of the National Center for Atmospheric Research Community Earth System Model (CESM1.2.2) and an off‐line Community Land Model (CLM4.5). The correlation between leaf area index (LAI) and surface evaporative fraction (ratio of latent to total turbulent heat flux) was substantially underpredicted compared to observations in the U.S. Southern Great Plains, while the correlation between soil moisture and evaporative fraction was overpredicted by CLM4.5. To estimate the impacts of these errors on climate prediction, we modified CLM4.5 by prescribing observed LAI, increasing soil resistance to evaporation, increasing minimum stomatal conductance, and increasing leaf reflectance. The modifications improved the predicted soil moisture‐evaporative fraction (EF) and LAI‐EF correlations in off‐line CLM4.5 and reduced the root‐mean‐square error in summer 2 m air temperature and precipitation in the coupled model. The modifications had the largest effect on prediction during a drought in summer 2006, when a warm bias in daytime 2 m air temperature was reduced from +6°C to a smaller cold bias of −1.3°C, and a corresponding dry bias in precipitation was reduced from −111 mm to −23 mm. The role of vegetation in droughts and heat waves is underpredicted in CESM1.2.2, and improvements in land surface models can improve prediction of climate extremes.
Analysis of the interdecadal variability of summer precipitation in central Japan using a reconstructed 106 year long oxygen isotope record from tree ring cellulose
Authors: Kurita Naoyuki , Nakatsuka Takeshi , Ohnishi Keiko , Mitsutani Takumi , Kumagai Tomo'omi
Published: October 2016

We present a unique proxy for reconstructing the interannual variability of summer precipitation associated with the quasi‐stationary front (Baiu front) in central Japan. The rainfall from the Baiu front has a relatively lower oxygen isotopic composition than other types of nonfrontal precipitation. The variability in the oxygen isotopes in summer rainfall is closely related to the Baiu frontal activity. In this study we used a mechanistic tree ring isotope model to reconstruct a 106 year long oxygen isotopic composition of precipitation during the early rainy season (June) based on the oxygen isotopic compositions of the annual rings of Chamaecyparis obtusa Endl trees from central Japan. The year‐to‐year variations of the isotopes over the most recent 25 years are associated with several teleconnection patterns that often lead to the Baiu precipitation anomalies in central Japan (such as the Pacific‐Japan (PJ) pattern, Silk Road pattern, and wave train pattern along the polar jet). Yet none of these external forcing mechanisms apply further back in time. From the 1950s to 1980s, the interannual isotopic variability is predominantly related to local factors such as anomalous intensification/weakening of the Bonin High. Before the 1950s, the variability of the oxygen isotopic composition of precipitation is mainly associated with a wave train pattern along the polar jet. The isotopic variability is predominantly linked to the PJ pattern, while the PJ index is correlated with El Niño–Southern Oscillation. These findings suggest that the teleconnection patterns influencing Baiu precipitation variability vary according to interdecadal time scales during the twentieth century.
Quantifying the anthropogenic dust emission from agricultural land use and desiccation of the Aral Sea in Central Asia
Authors: Xi Xin , Sokolik Irina N.
Published: October 2016

A regional dust model system is applied to quantify the anthropogenic dust emission in the post‐Soviet Central Asia from 2000 to 2014. Two physically based dust schemes suggest that a proportion of 18.3–32.8% of total dust emissions is contributed by agricultural land use and the desiccation of Aral Sea, whereas a simplified dust scheme yields higher estimates in the range of 49.7–56.5% depending on whether a static or dynamic preferential dust source function is used. The dust schemes also differ greatly in the spatial distribution of anthropogenic dust and the sensitivity to the use of land use intensity in separating natural and human‐made source areas, suggesting that the model representation of erosion threshold velocity, especially the role of vegetation, is a key source of model uncertainty in quantifying anthropogenic dust. The relative importance of agriculture and dried Aral Sea bed (Aralkum) differs greatly among the dust schemes. Despite the increased dust from the expansion of Aralkum, there is a negative trend in the anthropogenic dust proportion, indicating a shift of dust emission toward natural source areas. All dust schemes show a decrease in anthropogenic dust in response to land cover changes over agricultural lands.
Plate Boundary Observatory and related networks: GPS data analysis methods and geodetic products
Authors: Herring Thomas A. , Melbourne Timothy I. , Murray Mark H. , Floyd Michael A. , Szeliga Walter M. , King Robert W. , Phillips David A. , Puskas Christine M. , Santillan Marcelo , Wang Lei
Published: October 2016

The Geodesy Advancing Geosciences and EarthScope (GAGE) Facility Global Positioning System (GPS) Data Analysis Centers produce position time series, velocities, and other parameters for approximately 2000 continuously operating GPS receivers spanning a quadrant of Earth's surface encompassing the high Arctic, North America, and Caribbean. The purpose of this review is to document the methodology for generating station positions and their evolution over time and to describe the requisite trade‐offs involved with combination of results. GAGE GPS analysis involves formal merging within a Kalman filter of two independent, loosely constrained solutions: one is based on precise point positioning produced with the GIPSY/OASIS software at Central Washington University and the other is a network solution based on phase and range double‐differencing produced with the GAMIT software at New Mexico Institute of Mining and Technology. The primary products generated are the position time series that show motions relative to a North America reference frame and secular motions of the stations represented in the velocity field. The position time series themselves contain a multitude of signals in addition to the secular motions. Coseismic and postseismic signals, seasonal signals from hydrology, and transient events, some understood and others not yet fully explained, are all evident in the time series and ready for further analysis and interpretation. We explore the impact of analysis assumptions on the reference frame realization and on the final solutions, and we compare within the GAGE solutions and with others.
The Effect of the Microstructure on Trap‐Assisted Recombination and Light Soaking Phenomenon in Hybrid Perovskite Solar Cells
Authors: Shao Shuyan , Abdu‐Aguye Mustapha , Sherkar Tejas S. , Fang Hong‐Hua , Adjokatse Sampson , Brink Gert ten , Kooi Bart J. , Koster L. Jan Anton , Loi Maria Antonietta
Published: October 2016

Despite the rich experience gained in controlling the microstructure of perovskite films over the past several years, little is known about how the microstructure affects the device properties of perovskite solar cells (HPSCs). In this work, the effects of the perovskite film microstructure on the charge recombination and light‐soaking phenomenon in mixed halide HPSCs are investigated. Devices with noncompact perovskite morphology show a severe light soaking effect, with the power conversion efficiency (PCE) improved from 3.7% to 11.6% after light soaking. Devices with compact perovskite morphology show a negligible light soaking effect, with PCE slightly increased from 11.4% to 11.9% after light soaking. From device investigations, photoluminescence, and impedance spectroscopy measurements, it is demonstrated that interface electron traps at the grain boundaries as well as at the crystal surface dominate the light soaking effect. Severe trap‐assisted recombination takes place in HPSCs using noncompact films, while it is effectively eliminated in devices with compact films. Moreover, how the grain size of the perovskite film affects the light soaking phenomenon is investigated. In the case of compact perovskite films, the size of the grains has a limited effect on the light soaking. In these compact films, grains are fused and trap states are effectively reduced.
In Situ Confinement Pyrolysis Transformation of ZIF‐8 to Nitrogen‐Enriched Meso‐Microporous Carbon Frameworks for Oxygen Reduction
Authors: Lai Qingxue , Zhao Yingxuan , Liang Yanyu , He Jianping , Chen Junhong
Published: October 2016

Metal organic framework (MOF)‐derived nitrogen‐enriched nanocarbons have been proposed as promising metal‐free electrocatalysts for oxygen reduction reaction. However, the characteristic microporous feature of MOF‐derived carbon determined by the MOF structure significantly hinders the mass transfer and exposure of active sites, resulting in unsatisfactory electrocatalytic performance. Here an in situ confinement pyrolysis strategy that can simply but efficiently transform monodisperse ZIF‐8 polyhedrons to nitrogen‐enriched meso‐microporous carbon (NEMC) frameworks is reported. Using this strategy, 3D NEMC frameworks, 1D NEMC fibers, and 2D NEMC on graphene (NEMC/G) can be successfully obtained. As a metal‐free elctrocatalyst, optimized NEMC/G can reach a comparable electrocatalytic activity with superior stability and methanol resistance to commercial 30 wt% Pt/C catalyst in 0.1 m KOH solution. Such enhanced performance can be ascribed to the stable and highly open network consisting of NEMC and G with fully exposed active sites, thereby leading to durable catalytic activity.
Vertical 2D MoO2/MoSe2 Core–Shell Nanosheet Arrays as High‐Performance Electrocatalysts for Hydrogen Evolution Reaction
Authors: Chen Xiaoshuang , Liu Guangbo , Zheng Wei , Feng Wei , Cao Wenwu , Hu Wenping , Hu PingAn
Published: October 2016

Electrochemical water splitting is very attractive for green fuel energy production, but the development of active, stable, and earth‐abundant catalysts for the hydrogen evolution reaction (HER) remains a major challenge. Here, core–shell nanostructured architectures are used to design and fabricate efficient and stable HER catalysts from earth‐abundant components. Vertically oriented quasi‐2D core–shell MoO2/MoSe2 nanosheet arrays are grown onto insulating (SiO2/Si wafer) or conductive (carbon cloth) substrates. This core–shell nanostructure array architecture exhibits synergistic properties to create superior HER performance, where high density structural defects and disorders on the shell generated by a large crystalline mismatch of MoO2 and MoSe2 act as multiple active sites for HER, and the metallic MoO2 core facilitates charge transport for proton reduction while the vertical nanosheet arrays ensure fully exposed active sites toward electrolytes. As a HER catalyst, this electrode exhibits a low Tafel slope of 49.1 mV dec−1, a small onset potential of 63 mV, and an ultralow charge transfer resistance (Rct) of 16.6 Ω at an overpotential of 300 mV with a long cycling durability for up to 8 h. This work suggests that a quasi 2D core–shell nanostructure combined with a vertical array microstructure is a promising strategy for efficient water splitting electrocatalysts with scale‐up potential.
Design and Synthesis of “All‐in‐One” Multifunctional FeS2 Nanoparticles for Magnetic Resonance and Near‐Infrared Imaging Guided Photothermal Therapy of Tumors
Authors: Meng Zhouqi , Wei Fang , Ma Wujun , Yu Nuo , Wei Peiling , Wang Zhaojie , Tang Yueqin , Chen Zhigang , Wang Huiping , Zhu Meifang
Published: October 2016

The ideal theranostic nanoplatform for tumors is a single nanoparticle that has a single semiconductor or metal component and contains all multimodel imaging and therapy abilities. The design and preparation of such a nanoparticle remains a serious challenge. Here, with FeS2 as a model of a semiconductor, the tuning of vacancy concentrations for obtaining “all‐in‐one” type FeS2 nanoparticles is reported. FeS2 nanoparticles with size of ≈30 nm have decreased photoabsorption intensity from the visible to near‐infrared (NIR) region, due to a low S vacancy concentration. By tuning their shape/size and then enhancing the S vacancy concentration, the photoabsorption intensity of FeS2 nanoparticles with size of ≈350 nm (FeS2‐350) goes up with the increase of the wavelength from 550 to 950 nm, conferring the high NIR photothermal effect for thermal imaging. Furthermore, this nanoparticle has excellent magnetic properties for T2‐weighted magnetic resonance imaging (MRI). Subsequently, FeS2‐350 phosphate buffer saline (PBS) dispersion is injected into the tumor‐bearing mice. Under the irradiation of 915‐nm laser, the tumor can be ablated and the metastasis lesions in liver suffer significant inhibition. Therefore, FeS2‐350 has great potential to be used as novel “all‐in‐one” multifunctional theranostic nanoagents for MRI and NIR dual‐modal imaging guided NIR‐photothermal ablation therapy (PAT) of tumors.
A Sequentially Triggered Nanosystem for Precise Drug Delivery and Simultaneous Inhibition of Cancer Growth, Migration, and Invasion
Authors: Liu Ting , Lai Lanhai , Song Zhenhuan , Chen Tianfeng
Published: October 2016

The rational design of cancer‐targeted and bioresponsive drug delivery vehicles can enhance the anticancer efficacy of conventional chemotherapeutics and reduce their adverse side effects. However, the complexity of precise delivery and the ability to trigger drug release in specific tumor sites remain a challenging puzzle. Here, a sequentially triggered nanosystem composed of HER2 antibody with disulfide linkage as a surface decorator (HER2@NPs) is constructed for precise drug delivery and the simultaneous inhibition of cancer growth, migration, and invasion. The nanosystem actively accumulates in cancer cells, undergoes self‐immolative cleavage in response to biological thiols, and is degraded to form small nanoparticles. After internalization by receptor‐mediated endocytosis, the nanoparticles further disassemble under acidic conditions in the presence of lysozymes and cell lysates, leading to sequentially triggered drug release. The released payload triggers overproduction of reactive oxygen species and activates p53 and MAPKs pathways to induce cancer cell apoptosis. Moreover, HER2@NPs markedly suppress the migration and invasion of human bladder cancer cells at nontoxic concentrations. HER2@NPs demonstrate potent in vivo anticancer efficacy, but show no obvious histological damage to the major organs. Taken together, this study provides a valid tactic for the rational design of sequentially triggered nanosystems for precise drug delivery and cancer therapy.
A Truncated IL‐17RC Peptide Ameliorates Synovitis and Bone Destruction of Arthritic Mice
Authors: Du Yuxuan , Tong Yulong , Mei Wentong , Jia Junhui , Niu Menglin , Cao Wei , Lou Weiwei , Li Shentao , Li Zhanguo , Stinson W. Alexander , Yuan Huihui , Zhao Wenming
Published: October 2016

Peptide‐based therapy, such as modified peptides, has attracted increased attention. IL‐17 is a promising therapeutic target for autoimmune diseases, and levels of circulating bioactive IL‐17 are associated with rheumatoid arthritis severity. In this study, a modified truncated IL‐17RC is generated to ameliorate inflammation and bone destruction in arthritis. The truncated IL‐17RC binds to both IL‐17A and IL‐17F with higher binding capacity compared to nonmodified IL‐17RC. In addition, the truncated IL‐17RC reduces the secretion of inflammatory and osteoclastogenic factors induced by IL‐17A/F in vitro. Moreover, the administration of truncated IL‐17RC dramatically improves symptoms of inflammation and inhibited bone destruction in collagen‐induced arthritis mice. Collectively, these data demonstrate that modified truncated IL‐17RC peptide may be a more effective treatment strategy in the simultaneous inhibition of both IL‐17A and IL‐17F signaling, whereas the existing agents neutralize IL‐17A or IL‐17F alone. These suggest that the truncated IL‐17RC may be a potential candidate in the treatment of inflammatory associated bone diseases.
Partial slip boundary conditions for collisional granular flows at flat frictional walls
Authors: Yang Lei , Padding J. T. , Kuipers J. A. M.
Published: October 2016

We derive new boundary conditions (BCs) for collisional granular flows of spheres at flat frictional walls. A new theory is proposed for the solids stress tensor, translational and rotational energy dissipation rate per unit area and fluxes of translational and rotational fluctuation energy. In the theory we distinguish between sliding and sticking collisions and include particle rotation. The predictions are compared with literature results obtained from a discrete particle model evaluated at a given ratio of rotational to translational granular temperature. We find that the new theory is in better agreement with the observed stress ratios and heat fluxes than previous kinetic theory predictions. Finally, we carry out two fluid model simulations of a bubbling fluidized bed with the new BCs, and compare the simulation results with those obtained from discrete particle simulations. The comparison reveals that the new BCs are better capable of predicting solids axial velocity profiles, solids distribution near the walls and granular temperatures. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1853–1871, 2017
Integration of biofuels intermediates production and nutrients recycling in the processing of a marine algae
Authors: Teymouri Ali , Kumar Sandeep , Barbera Elena , Sforza Eleonora , Bertucco Alberto , Morosinotto Tomas
Published: October 2016

The cost‐effective production of liquid biofuels from microalgae is limited by several factors such as recovery of the lipid fractions as well as nutrients management. Flash hydrolysis, a rapid hydrothermal process, has been successfully applied to fractionate the microalgal biomass into solid biofuels intermediates while recovering a large amount of the nutrients in the aqueous phase (hydrolyzate) in a continuous flow reactor. The aim of the work is to enhance the quality of a high‐ash containing marine algae Nannochloropsis gaditana as biofuel feedstock while recycling nutrients directly for algae cultivation. Characterization of products demonstrated an increase in extractable lipids from 33.5 to 65.5 wt % (dry basis) while retaining the same fatty acid methyl ester profile, in addition to diminution of more than 70 wt % of ash compared to raw microalgae. Moreover, the hydrolyzate was directly used to grow a microalga of the same genus. © 2016 American Institute of Chemical EngineersAIChE J, 63: 1494–1502, 2017
Risk factors for infections in myelofibrosis: role of disease status and treatment. A multicenter study of 507 patients
Authors: Polverelli Nicola , Breccia Massimo , Benevolo Giulia , Martino Bruno , Tieghi Alessia , Latagliata Roberto , Sabattini Elena , Riminucci Mara , Godio Laura , Catani Lucia , Nicolosi Maura , Perricone Margherita , Sollazzo Daria , Colafigli Gioia , Campana Anna , Merli Francesco , Vitolo Umberto , Alimena Giuliana , Martinelli Giovanni , Lewis Russell E. , Vianelli Nicola , Cavo Michele , Palandri Francesca
Published: October 2016

Although infectious complications represent a relevant cause of morbidity and mortality in patients with myelofibrosis (MF), little is known about their incidence, outcome and risk factors. We retrospectively evaluated a cohort of 507 MF patients, diagnosed between 1980 and 2014 in five Italian hematology centers, to define the epidemiology of infections and describe the impact of ruxolitinib (RUX) treatment. Overall, 112 patients (22%) experienced 160 infectious events (grade 3–4, 45%) for an incidence rate of 3.9% per patient‐year. Infections were mainly bacterial (78%) and involving the respiratory tract (52% of cases). Also, viral (11%) and fungal infections (2%) were recorded. Overall, infections were fatal in 9% of the cases. Among baseline features, high/intermediate‐2 IPSS category (HR 1.8, 95%CI:1.2–2.7; P = 0.02) and spleen length ≥10 cm below left costal margin (HR 1.6, 95%CI:1.1–2.5; P = 0.04) were associated with higher infectious risk in multivariate analysis. Overall, the rate of infections was higher in the cohort of 128 RUX‐treated patients (44% vs. 20%, P < 0.001). In conclusion, IPSS‐category and splenomegaly, emerged as the main risk factors for infections in MF. RUX‐treated patients experienced significantly more infection episodes; however, future prospective studies are needed to isolate the confounding contribution of other risk factors such as disease stage. Am. J. Hematol. 92:37–41, 2017. © 2016 Wiley Periodicals, Inc.
Chronic granulomatous disease: Clinical, functional, molecular, and genetic studies. The Israeli experience with 84 patients
Authors: Wolach Baruch , Gavrieli Ronit , de Boer Martin , van Leeuwen Karin , Berger‐Achituv Sivan , Stauber Tal , Ben Ari Josef , Rottem Menachem , Schlesinger Yechiel , Grisaru‐Soen Galia , Abuzaitoun Omar , Marcus Nufar , Zion Garty Ben , Broides Arnon , Levy Jakov , Stepansky Polina , Etzioni Amos , Somech Raz , Roos Dirk
Published: October 2016

Chronic granulomatous disease (CGD) is an innate immunodeficiency with a genetic defect of the nicotinamide adenosine dinucleotide phosphate, reduced, oxidase components. This leads to decreased reactive oxygen species (ROS) production, which renders patients susceptible to life‐threatening infections. Over the course of 30 years, we diagnosed CGD in 84 patients from 61 families using functional, molecular, and genetic studies. The incidence of CGD in Israel is 1.05 per 100,000 live‐births in the Jewish population and 1.49 in the Israeli Arab population. We diagnosed 52 patients (62%) with autosomal recessive inheritance (AR‐CGD) and 32 (38%) with X‐linked recessive inheritance (XLR‐CGD). Consanguinity was detected in 64% of AR‐CGD families (14% in Jews and 50% in Israeli Arabs). We found 36 different mutations (23 in XLR‐CGD and 13 in AR‐CGD patients), 15 of which were new. The clinical spectrum of CGD varied from mild to severe disease in both XLR and AR forms, although the AR subtype is generally milder. Further, residual ROS production correlated with milder clinical expression, better prognosis and improved overall survival. Patients with recurrent pyogenic infections developed fibrosis and hyperinflammatory states with granuloma formation. The management of CGD has progressed substantially in recent years, evolving from a fatal disease of early childhood to one of long‐term survival. Our present cohort displays an encouraging 81% overall long term survival. Early hematopoietic stem cell transplantation is advisable before tissue damage is irreversible. Successful transplantation was performed in 18/21 patients. Therapeutic gene modification could become an alternative cure for CGD. Am. J. Hematol. 92:28–36, 2017. © 2016 Wiley Periodicals, Inc.
Development and validation of an assessment tool for a national young worker curriculum
Authors: Guerin Rebecca J. , Okun Andrea H. , Kelley Patricia
Published: October 2016

Background

An online, multiple‐choice assessment was developed and validated for Youth@Work‐Talking Safety, a NIOSH curriculum that equips middle and high school students with foundational workplace safety and health knowledge and skills.

Methods

Classical Test Theory was used for the test development and validation; the Jaeger method was used for cut score determination. A total of 118 multiple‐choice items were developed to measure the acquisition of knowledge and skills taught through the NIOSH curriculum. Pilot testing was conducted with 192 8–12th grade students and a cut score was determined.

Results

The mean score for all test‐takers on the Talking Safety assessment was 80.9%; total test reliability measured using an Alpha/KR20 statistic was 0.93. A minimum passing (cut) score of 74% was established.

Conclusions

The assessment provides an objective measure of students' acquisition of the foundational workplace safety and health competencies taught through the Talking Safety curriculum. Am. J. Ind. Med. 59:969–978, 2016. © 2016 Wiley Periodicals, Inc.
Hydrazone‐Initiated Reaction Cascades
Authors: Chen Po‐An , May Jeremy A.
Published: October 2016

In this Focus Review, recently reported cascade reactions that are initiated from hydrazones are described. These cascades are grouped based on the mechanistic characteristics of the reactions paired with the hydrazone‐based transformations. Reactions in which the hydrazone simply acts as a surrogate for a diazo group are not discussed, but rather the focus is maintained on reactions with multiple mechanistically distinct steps. Sigmatropic, ene–yne metathesis, C−H bond insertion, ylide, and cross‐coupling examples are given. The versatility of the hydrazone functional group allows for many transformations, and yet is also compatible with many other transformations. Finally, a discussion of potential future directions for hydrazone‐initiated cascades is presented.
Designing Vasicine‐Derived Ligands and Their Application for Ruthenium‐Catalyzed Transfer Hydrogenation Reactions in Water: Synthesis of Amines and Alcohols
Authors: Sharma Sushila , Kumar Manoranjan , Nayal Onkar S. , Thakur Maheshwar S. , Bhatt Vinod , Kumar Neeraj , Singh Bikram , Sharma Upendra
Published: October 2016

Six quinazoline ligands (i.e., 3–8) were synthesized by starting from vasicine and vasicinone, and their applications towards ruthenium‐catalyzed transfer hydrogenation reactions were evaluated. The 3/[RuCl2(p‐cymene)]2 catalytic system was assessed for its use in the ruthenium‐catalyzed transfer hydrogenation reaction of aldehydes, ketones, and imines to give the corresponding alcohols and amines and also assessed for its use in the direct reductive amination of carbonyl compounds with anilines. The 3/[RuCl2(p‐cymene)]2 catalytic system demonstrated good to excellent activity in water with sodium formate as the hydrogen source. Current studies have revealed that among all of the synthesized ligands, those that have secondary amine groups and a rigid backbone are more active towards transfer hydrogenation reactions of unsaturated compounds.
A Neanderthal deciduous human molar with incipient carious infection from the Middle Palaeolithic De Nadale cave, Italy
Authors: Arnaud Julie , Benazzi Stefano , Romandini Matteo , Livraghi Alessandra , Panetta Daniele , Salvadori Piero A. , Volpe Lisa , Peresani Marco
Published: October 2016

Objectives

The aim of the study is the assessment of Nadale 1, a Neanderthal deciduous tooth recently discovered in Northeastern Italy in the De Nadale cave (Middle Palaeolithic). Together with the clear archaeological context of the site, this study brings new insight on Neanderthal behavior and dental morphological variability.

Materials and methods

We used microCT data to provide a morphological description and morphometric analysis (diameter measurements and dental tissue volumes) of the Nadale 1 human tooth. Microwear analysis, taphonomical investigation and caries identification were performed using a stereomicroscope and Scanning Electron Microscope.

Results

In terms of morphology (i.e., incipient tuberculum molare, marked mesial marginal ridge and well‐developed mid‐trigonid crest connecting the protoconid and the metaconid, deep anterior fovea) and size, Nadale 1 presents features frequently observed in Neanderthal lower first deciduous molars. Microscope investigations reveal the presence of a small pit which could be correlated to an incipient caries.

Conclusion

Nadale 1 expands the Italian Middle Palaeolithic fossil record and provides further information on Neanderthal dm1s in terms of dimensional and morphological variability. Furthermore, the presence of an incipient caries brings further data on Neanderthal diet.
Beobachtung von ssDNA‐Bindung an die DnaB‐Helikase von Helicobacter pylori mittels Festkörper‐NMR‐Spektroskopie
Authors: Wiegand Thomas , Cadalbert Riccardo , Gardiennet Carole , Timmins Joanna , Terradot Laurent , Böckmann Anja , Meier Beat H.
Published: October 2016

DnaB‐Helikasen sind ATP‐getriebene bakterielle Enzyme, die doppelsträngige DNA während der DNA‐Replikation entwinden. In dieser Arbeit untersuchen wir das sequentielle Binden des “nicht‐hydrolysierbaren” ATP‐Analogons AMP‐PNP und von einfachsträngiger (ss) DNA an die dodekaedrische DnaB‐Helikase von Helicobacter pylori mittels Festkörper‐NMR‐Spektroskopie. Mithilfe von Phosphor‐Kreuzpolarisationsexperimenten wird das Binden von AMP‐PNP und DNA an die Helikase beobachtet, während Veränderungen in den 13C‐chemischen Verschiebungen (chemical‐shift perturbations, CSPs) Konformationsänderungen des Proteins detektieren. Durch Zugabe von AMP‐PNP geht die Helikase in eine Konformation über, welche ssDNA bindet, wohingegen AMP‐PNP hydrolysiert und bei DNA‐Bindung freigesetzt wird. Unsere Beobachtungen geben Aufschluss über die Konformationsänderungen, die durch Wechselwirkung mit AMP‐PNP ausgelöst werden und die Voraussetzung für das Binden von ssDNA an H. pylori DnaB in vitro sind. Ferner zeigen sie den Grad an Details, welchen die Festkörper‐NMR zur Charakterisierung von Protein‐DNA‐Wechselwirkungen und dem Zusammenspiel mit ATP oder seinen Analoga zu liefern vermag.
Synthesis of Pyrrolidines and Pyrrolizidines with α‐Pseudoquaternary Centers by Copper‐Catalyzed Condensation of α‐Diazodicarbonyl Compounds and Aryl γ‐Lactams
Authors: Goudedranche Sébastien , Besnard Céline , Egger Léo , Lacour Jérôme
Published: October 2016

N‐aryl γ‐lactams react intermolecularly with acceptor–acceptor diazo reagents, usually dicarbonyl compounds, in a copper‐catalyzed process to yield functionalized pyrrolidines with α‐pseudoquaternary centers. As 1,2‐acyl or ‐phosphoryl migration is preferred, single regioisomers are obtained. Furthermore, in the presence of a Lewis acid, subsequent Friedel–Crafts reactions yield tricyclic pyrrolizidines in excellent yields (90–96 %) and diastereoselectivities (up to >20:1).
Reversible Dihydrogen Activation by Reduced Aryl Boranes as Main‐Group Ambiphiles
Authors: von Grotthuss Esther , Diefenbach Martin , Bolte Michael , Lerner Hans‐Wolfram , Holthausen Max C. , Wagner Matthias
Published: October 2016

A new approach to main‐group H2 activation combining concepts of transition‐metal and frustrated Lewis pair chemistry is reported. Ambiphilic, metal‐like reactivity toward H2 can be conferred to 9,10‐dihydro‐9,10‐diboraanthracene (DBA) acceptors by the injection of two electrons. The resulting [DBA]2− ions cleave the H−H bond with the formation of hydridoborates under moderate conditions (T=50–100 °C; p<1 atm). Depending on the boron‐bonded substituents R, the addition is either reversible (R=C≡CtBu) or irreversible (R=H). The reaction rate is strongly influenced by the nature and the coordination behavior of the countercation (Li+ slower than K+). Quantum‐chemical calculations support the experimental observations and suggest a concerted, homolytic addition of H2 across both boron atoms. As proven by the successful conversion of Me3SiCl into Me3SiH, the system Li2[DBA]/H2 appears generally relevant for the hydrogenation of element–halide bonds.
Monitoring ssDNA Binding to the DnaB Helicase from Helicobacter pylori by Solid‐State NMR Spectroscopy
Authors: Wiegand Thomas , Cadalbert Riccardo , Gardiennet Carole , Timmins Joanna , Terradot Laurent , Böckmann Anja , Meier Beat H.
Published: October 2016

DnaB helicases are bacterial, ATP‐driven enzymes that unwind double‐stranded DNA during DNA replication. Herein, we study the sequential binding of the “non‐hydrolysable” ATP analogue AMP‐PNP and of single‐stranded (ss) DNA to the dodecameric DnaB helicase from Helicobacter pylori using solid‐state NMR. Phosphorus cross‐polarization experiments monitor the binding of AMP‐PNP and DNA to the helicase. 13C chemical‐shift perturbations (CSPs) are used to detect conformational changes in the protein upon binding. The helicase switches upon AMP‐PNP addition into a conformation apt for ssDNA binding, and AMP‐PNP is hydrolyzed and released upon binding of ssDNA. Our study sheds light on the conformational changes which are triggered by the interaction with AMP‐PNP and are needed for ssDNA binding of H. pylori DnaB in vitro. They also demonstrate the level of detail solid‐state NMR can provide for the characterization of protein–DNA interactions and the interplay with ATP or its analogues.
Environmentally friendly and highly efficient synthesis of benzoxazepine and malonamide derivatives using HPA/TPI‐Fe3O4 nanoparticles as recoverable catalyst in aqueous media
Authors: Vessally Esmail , Hosseinzadeh‐Khanmiri Rahim , Babazadeh Mirzaagha , Ghorbani‐Kalhor Ebrahim , Edjlali Ladan
Published: October 2016

A magnetic inorganic–organic nanohybrid material (HPA/TPI‐Fe3O4 NPs) was produced as an efficient, highly recyclable and eco‐friendly catalyst for the one‐pot multi‐component synthesis of malonamide and 2,3,4,5‐tetrahydrobenzo[b][1,4]oxazepine derivatives with high yields in short reaction times (25–35 min) in aqueous media at room temperature. The nanohybrid catalyst was prepared by the chemical anchoring of H6P2W18O62 onto the surface of modified Fe3O4 nanoparticles (NPs) with N‐[3‐(triethoxysilyl)propyl]isonicotinamide (TPI) linker. The magnetic recoverable catalyst was easily recycled at least ten times without any loss of catalytic activity.
Au‐ and Ag‐loaded MnO2 nanostructures supported on nitrogen‐ and nitrogen–sulfur‐doped pyroproteins: Synthesis and catalytic activity in organic transformations
Authors: Hezarkhani Zeinab , Shaabani Ahmad
Published: October 2016

Four novel Au‐ and Ag‐loaded MnO2 nanostructures supported on nitrogen‐doped pyroprotein of natural silk (Au–MnO2@PPNS and Ag–MnO2@PPNS) and nitrogen–sulfur‐doped pyroprotein of natural wool (Au–MnO2@PPNW and Ag–MnO2@PPNW) have been synthesized. Nitrogen‐ and nitrogen–sulfur‐doped pyroproteins were prepared by carbonization of natural silk and wool proteins, respectively. The catalysts were investigated for the aerobic oxidation of aromatic hydrocarbons of petroleum naphtha and the aerobic oxidative synthesis of 2‐phenylbenzo[d]thiazoles, 2‐phenyl‐1H‐benzo[d]imidazoles and 2‐phenyl‐4‐quinazolinones in the absence of any co‐promoter and additional oxidizing reagent. The prepared catalytic systems showed higher catalytic activity in comparison to aggregated catalysts.
Effect of fluorinated/non‐fluorinated β‐diketones and side‐chain branching of N‐protected amino acids on the antibacterial potential of new heptacoordinated monobutyltin(IV) complexes
Authors: Maheshwari Karuna , Srivastava Manish Kumar , Saxena Sanjiv , Jain Asha
Published: October 2016

The effect of fluorinated/non‐fluorinated β‐diketones and side‐chain branching of N‐protected amino acids on the antibacterial potential of new heptacoordinated monobutyltin(IV) complexes was investigated. New heptacoordinated monobutyltin(IV) complexes having the general formulae BuSn(A)2B and BuSnA(B)2 [where AH = (1,3‐dihydro‐1,3‐dioxo‐α‐(substituted)‐2H‐isoindole‐2‐acetic acids, N‐protected amino acids), R = CH(CH3)CH2CH3: A1H; R = CH(CH3)2: A2H; and BH = R'COCH2COR″ (β‐diketones), R′ = R″ = CH3: B1H; R′ = CH3, R″ = C6H5: B2H; R′ = CF3, R″ = C6H5: B3H] were synthesized. Complexes BuSn(A)2B and BuSnA(B)2 were generated by the reaction of sodium salts of the ligands AH and BH with BuSnCl3 in 2:1:1 and 1:2:1 molar ratios, respectively. These newly generated complexes were characterized in physicochemical and spectroscopic studies. These complexes contain heptacoordinated tin centres as revealed by 119Sn NMR chemical shift values. Some of the newly generated complexes and their corresponding ligands were screened for their antibacterial activity to study the structure–activity relationship.
Application of a biological‐based nanomagnetic catalyst in the synthesis of bis‐pyrazols and pyrano[3,2‐c]pyrazoles
Authors: Zolfigol Mohammad Ali , Navazeni Mahdiyeh , Yarie Meysam , Ayazi‐Nasrabadi Roya
Published: October 2016

{Fe3O4@SiO2@(CH2)3‐thiourea dioxide‐SO3H/HCl}, a newly reported nanomagnetic core–shell supported solid acid catalyst, was successfully employed in the preparation of 4,4′‐(arylmethylene)bis(1H–pyrazol‐5‐ol) and pyrano[3,2‐c]pyrazole derivatives. The presented methods are very efficient and high‐yielding. Also, the catalyst exhibited powerful potential for reusability in both types of reactions.
Development and material properties of poly(lactic acid)/poly(3‐hydroxybutyrate‐co−3‐hydroxyvalerate)‐based nanocrystalline cellulose nanocomposites
Authors: Dasan Y. K. , Bhat A. H. , Faiz A.
Published: October 2016

This study is focused on the development and analysis of the thermal and structural behavior of nanocrystalline cellulose (NCC)‐based bionanocomposites (BCs). Nanocrystalline cellulose was prepared by controlled acid hydrolysis of oil palm empty fruit bunch fibers. The resulting NCC was surface modified using TEMPO‐mediated oxidation and solvent exchange methods for surface functionalization and also to improve dispersion of fillers. Solvent exchange NCC reinforced polymer blend containing poly(lactic acid)/poly‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) was prepared by using solution casting technique at various NCC loading percentages. The addition of NCC resulted in the improvement of structural, thermal, and mechanical properties of BCs as compared to that of the polymer blend. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44328.
The grafting reaction of epoxycyclohexyl polyhedral oligomeric silsesquioxanes with carboxylic methoxypolyethylene glycols and the properties of composite solid polymer electrolytes with the graftomer
Authors: Mei Hua , Wang Ran , Ren Wentan , Zhang Yong
Published: October 2016

A novel organic–inorganic hybrid of epoxycyclohexyl polyhedral oligomeric silsesquioxane (e‐POSS)–grafted carboxylic methoxypolyethylene glycols (mPEG‐COOH), that is, a POSS‐mPEG graftomer, was synthesized. The grafting reaction of e‐POSS and mPEG‐COOH was characterized by Fourier transform infrared (FTIR) and 1H‐NMR spectroscopy. Then the graftomer was used to develop new composite solid polymer electrolyte (SPE) films with a carboxylated nitrile rubber–epoxidized natural rubber (XNBR‐ENR) self‐crosslinked blend system as a dual‐phase polymer matrix. The self‐crosslinked reaction of the XNBR‐ENR matrix was investigated using ATR‐FTIR. The morphology of the SPE films and the distribution of lithium salt were investigated using field emission scanning electron microscopy and X‐ray diffraction, and the result illustrated that the addition of POSS‐mPEG could promote and accelerate the dissociation of LiClO4. The best effect within the range of this study was achieved when 25 phr POSS‐mPEG was involved. The differential scanning calorimetry analysis proved that the glass‐transition temperature of the composite SPE films was reduced with the increase of POSS‐mPEG. The ionic conductivity of the composite SPE films was investigated by electrochemical impedance spectroscopy. The highest ionic conductivity in this study of 2.57 × 10−5 S cm−1 was obtained with 25 phr POSS‐mPEG loading. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44460.
Electropolymerization and energy storage of poly[Ni(salphen)]/MWCNT composite materials for supercapacitors
Authors: Chen Cheng , Zhu Zhixun , Li Xinping , Li Jianling
Published: October 2016

Ni(salphen), a Schiff base ligand compound, was synthesized and electropolymerized on multiwalled carbon nanotube (MWCNT) electrodes in an acetonitrile solution via the pulse potentiostatic method and then applied as a supercapacitor electrode material. The polymerization mode was investigated through methyl replacement in the para‐position of phenyl rings in the Ni(salphen) monomer, and it was found that the Ni(salphen) monomers would polymerize by the generation of CC bonds between the phenyl rings in the para‐position of the phenol moieties. The optimum condition for polymerization was evaluated, and when the polymerization time was 8 min, poly[Ni(salphen)] exhibited a specific capacitance up to 200 F g−1 at a current density of 0.1 mA cm−2, and the capacitance remains at 164 F g−1 at 20 mA cm−2. The energy density of the poly[Ni(salphen)] electrode reached 40 Wh kg−1 at 0.1 mA cm−2, about eight times greater than for a pure MWCNT electrode. Electrochemical performances were investigated, and the composites showed good redox property and ion transfer capability. This work showed that Ni(salphen) may be an attractive material in supercapacitors© 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44464.
Preparation and properties of gel‐filled PVDF separators for lithium ion cells
Authors: Li Hao , Chao Chun‐Ying , Han Pei‐Lin , Yan Xiao‐Ran , Zhang Hong‐Hao
Published: October 2016

Polyether gel‐filled poly(vinylidene fluoride) separators (GF‐PVDF separators) were prepared by means of thermal crosslinking of poly(ethylene glycol) methyl ether acrylate (PEGMEA) and poly(ethylene glycol) diacrylate (PEGDA) as gel constituents. The intrinsic properties of GF‐PVDF and their corresponding gel polymer electrolyte (GPE) were characterized by SEM, DSC, and electrochemical methods. It was found a relatively better GPE could be got when the filled polyether content no more than 60 wt % and its ion conductivity could reach 1.3 × 10−3 S cm−1. The GPE is compatible with anode and cathode of lithium ion battery at high voltage and its electrochemical window is 4.6 V (vs. Li/Li+). The coulombic efficiency could reach 94% after 100 cycles for the cells using such GPE. The results reveal that the composite polymer electrolyte qualifies as a potential application in lithium cells. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44473.
Effects of styrene–acrylonitrile contents on the properties of ABS/SAN blends for fused deposition modeling
Authors: Zhu Jin , Hu Yufei , Tang Yijing , Wang Biao
Published: October 2016

This paper was to assess the effects of styrene–acrylonitrile (SAN) contents on the glass transition temperature (Tg), melt flow index (MFI), and mechanical properties of acrylonitrile–butadiene–styrene (ABS)/SAN blends for fused deposition modeling (FDM) process. The addition of SAN had little effects on Tg but could decrease the MFI and elongation at break while improving the tensile strength and modulus of ABS/SAN blends. For both longitudinal direction and transverse direction FDM printed specimens, the incorporation of SAN improved mechanical properties without sacrificing dimensional stability. This result was mainly attributed to the increasing content of continuous phase (SAN phase) and improvement in adhesion quality. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44477.
Influence of ionic liquid on the polymer–filler coupling and mechanical properties of nano‐silica filled elastomer
Authors: Zhang Xumin , Xue Xiaodong , Jia Hongbing , Wang Jingyi , Ji Qingmin , Xu Zhaodong
Published: October 2016

The natural rubber (NR) nanocomposites were fabricated by filling ionic liquid (1‐allyl‐3‐methyl‐imidazolium chloride, AMI) modified nano‐silica (nSiO2) in NR matrix through mechanical mixing and followed by a cure process. Based on the measurements of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), solid state nuclear magnetic resonance spectroscopy, and Raman spectroscopy, it was proved that AMI could interact with nSiO2 through hydrogen bonds. With the increase of AMI content, the curing rate of nSiO2/NR increased. The results of bound rubber and dynamic mechanical properties showed that polymer–filler interaction increased with the modification of nSiO2. Morphology studies revealed that modification of nSiO2 resulted in a homogenous dispersion of nSiO2 in NR matrix. AMI modified nSiO2 could greatly enhance the tensile strength and tear strength of nSiO2/NR nanocomposites. Compared to unmodified nSiO2/NR nanocomposite, the tensile strength of AMI modified nSiO2/NR nanocomposite increased by 102%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44478.