bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of ambient water intrusion on coral reef acidification in the Chuuk lagoon, located in the coral‐rich western Pacific Ocean
Authors: Ko Young Ho , Lee Kitack , Noh Jae Hoon , Lee Charity M. , Kleypas Joan A. , Jeong Hae Jin , Kim Kwang Young
Published: April 2016

Weekly carbonate chemistry condition data recorded between 2008 and 2014 in the Chuuk lagoon (7.3°N and 151.5°E) of the Federated States of Micronesia, located in the western Pacific Ocean, were analyzed. The results showed that, during periods of weak intrusion of ambient seawater from the surrounding open ocean, two internal biological processes (calcification and respiration) reinforced each other and together lowered the pH of the reef water for extended periods, ranging from a few to several months. The analysis indicated that reduced intrusion of ambient water is associated with periods of low wind speeds. Such conditions increase the residence time of reef water, thus promoting acidification by respiration and calcification. This phenomenon likely affects many other areas of the coral‐rich western Pacific Ocean, which contains 50% of global coral reefs and in which the degree of ambient water intrusion into the atolls has been shown to be closely associated with the El Niño–Southern Oscillation‐induced wind speed change.
Mangrove pore water exchange across a latitudinal gradient
Authors: Tait Douglas R. , Maher Damien T. , Macklin Paul A. , Santos Isaac R.
Published: April 2016

We combined observations of the natural tracer radon (222Rn) with hydrodynamic models across a broad latitudinal gradient covering several climate zones to estimate pore water exchange rates in mangroves. Pore water exchange ranged from 2.1 to 35.5 cm d−1 from temperate to tropical regions and averaged 16.3 ± 5.1 cm d−1. If upscaled to the global weighted mangrove area, pore water exchange in mangroves would recirculate the entire volume of water overlying the continental shelf in less than 153 years. Although pore water exchange (recirculated seawater) and river discharge represent different pathways for water entering the coastal ocean, the estimated global mangrove pore water exchange would be equal to approximately one third of annual global river discharge to the ocean (3.84 × 1013 m3 yr−1). Because biogeochemical processes in mangroves are largely dependent on pore water exchange, these large exchange rates have major implications for coastal nutrient, carbon, and greenhouse gas cycling in tropical marine systems.
Near‐surface salinity and stratification in the north Bay of Bengal from moored observations
Authors: Sengupta Debasis , Bharath Raj G. N. , Ravichandran M. , Sree Lekha J. , Papa Fabrice
Published: April 2016

A thin layer of fresh water from summer monsoon rain and river runoff in the Bay of Bengal (BoB) has profound influence on air‐sea interaction across the south Asian region, but the mechanisms that sustain the low‐salinity layer are as yet unknown. Using the first long time series of high‐frequency observations from a mooring in the north BoB and satellite salinity data, we show that fresh water from major rivers is transported by large‐scale flow and eddies, and shallow salinity stratification persists from summer through the following winter. The moored observations show frequent 0.2–1.2 psu salinity jumps with time scales of 10 min to days, due to O(1–10) km submesoscale salinity fronts moving past the mooring. In winter, satellite sea surface temperature shows 10 km wide filaments of cool water, in line with moored data. Rapid salinity and temperature changes at the mooring are highly coherent, suggesting slumping of salinity‐dominated fronts. Based on these observations, we propose that submesoscale fronts may be one of the important drivers for the persistent fresh layer in the north BoB.
Ephemerality of discrete methane vents in lake sediments
Authors: Scandella Benjamin P. , Pillsbury Liam , Weber Thomas , Ruppel Carolyn , Hemond Harold F. , Juanes Ruben
Published: April 2016

Methane is a potent greenhouse gas whose emission from sediments in inland waters and shallow oceans may both contribute to global warming and be exacerbated by it. The fraction of methane emitted by sediments that bypasses dissolution in the water column and reaches the atmosphere as bubbles depends on the mode and spatiotemporal characteristics of venting from the sediments. Earlier studies have concluded that hot spots—persistent, high‐flux vents—dominate the regional ebullitive flux from submerged sediments. Here the spatial structure, persistence, and variability in the intensity of methane venting are analyzed using a high‐resolution multibeam sonar record acquired at the bottom of a lake during multiple deployments over a 9 month period. We confirm that ebullition is strongly episodic, with distinct regimes of high flux and low flux largely controlled by changes in hydrostatic pressure. Our analysis shows that the spatial pattern of ebullition becomes homogeneous at the sonar's resolution over time scales of hours (for high‐flux periods) or days (for low‐flux periods), demonstrating that vents are ephemeral rather than persistent, and suggesting that long‐term, lake‐wide ebullition dynamics may be modeled without resolving the fine‐scale spatial structure of venting.
Influence of current velocity and wind speed on air‐water gas exchange in a mangrove estuary
Authors: Ho David T. , Coffineau Nathalie , Hickman Benjamin , Chow Nicholas , Koffman Tobias , Schlosser Peter
Published: April 2016

Knowledge of air‐water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h−1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas exchange parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).
Direct measurements of air‐sea CO2 exchange over a coral reef
Authors: McGowan Hamish A. , MacKellar Mellissa C. , Gray Michael A.
Published: April 2016

Quantification of CO2 exchange with the atmosphere over coral reefs has relied on microscale measurements of pCO2 gradients across the air‐sea interfacial boundary; shipboard measurements of air‐sea CO2 exchange over adjacent ocean inferred to represent over reef processes or ecosystem productivity modeling. Here we present by way of case study the first direct measurements of air‐sea CO2 exchange over a coral reef made using the eddy covariance method. Research was conducted during the summer monsoon over a lagoonal platform reef in the southern Great Barrier Reef, Australia. Results show the reef flat to be a net source of CO2 to the atmosphere of similar magnitude as coastal lakes, while adjacent shallow and deep lagoons were net sinks as was the surrounding ocean. This heterogeneity in CO2 exchange with the atmosphere confirms need for spatially representative direct measurements of CO2 over coral reefs to accurately quantify their role in atmospheric carbon budgets.
Immersion mode ice nucleation measurements with the new Portable Immersion Mode Cooling chAmber (PIMCA)
Authors: Kohn Monika , Lohmann Ulrike , Welti André , Kanji Zamin A.
Published: April 2016

The new Portable Immersion Mode Cooling chAmber (PIMCA) has been developed for online immersion freezing of single‐immersed aerosol particles. PIMCA is a vertical extension of the established Portable Ice Nucleation Chamber (PINC). PIMCA immerses aerosol particles into cloud droplets before they enter PINC. Immersion freezing experiments on cloud droplets with a radius of 5–7 μm at a prescribed supercooled temperature (T) and water saturation can be conducted, while other ice nucleation mechanisms (deposition, condensation, and contact mode) are excluded. Validation experiments on reference aerosol (kaolinite, ammonium sulfate, and ammonium nitrate) showed good agreement with theory and literature. The PIMCA‐PINC setup was tested in the field during the Zurich AMBient Immersion freezing Study (ZAMBIS) in spring 2014 in Zurich, Switzerland. Significant concentrations of submicron ambient aerosol triggering immersion freezing at T > 236 K were rare. The mean frozen cloud droplet number concentration was estimated to be 7.22·105 L−1 for T < 238 K and determined from the measured frozen fraction and cloud condensation nuclei (CCN) concentrations predicted for the site at a typical supersaturation of SS = 0.3%. This value should be considered as an upper limit of cloud droplet freezing via immersion and homogeneous freezing processes. The predicted ice nucleating particle (INP) concentration based on measured total aerosol larger than 0.5 μm and the parameterization by DeMott et al. (2010) at T = 238 K is INPD10=54 ± 39 L−1. This is a lower limit as supermicron particles were not sampled with PIMCA‐PINC during ZAMBIS.
The Use of27Al NMRto Study Aluminum Compounds: A Survey of the Last 25 Years
Authors: Martineau Charlotte , Taulelle Francis , Haouas Mohamed
Published: April 2016

Use of27Al nuclear magnetic resonance (NMR) spectroscopy for the study of the chemistry of aluminum in a variety of compounds during the last 25 years is reported. A compilation of NMR data, including chemical shifts and heteronuclear scalar couplings, is provided for a wide range of families of aluminum compounds in both solution and solid state. Recent methodological and technological advances in the field of quadrupolar NMR are detailed and their applications to27Al nucleus are illustrated. The potential of this technique is exemplified with some representative studies of relevance to mineral, biological, and organic aluminum‐based systems.
Advances in the Catalysis of Organic Processes by Metal Phenolates
Authors: Da Silva Serra Maria Elisa , Murtinho Dina M. B.
Published: April 2016

Transition‐metal catalysts with phenolate ligands comprise a great variety of compounds with appropriate characteristics capable of promoting numerous reactions of extreme importance in synthetic organic chemistry. Included in these transformations are oxidations of alkenes, sulfides, alcohols, and alkanes, cyanations, alkynylations, alkylations, hydroaminations, and nitroaldol reactions. An extensive review of the catalysis of organic processes by metal phenolates has been presented in a previous volume of this series. This chapter is an update of the advances published from 2011 to the beginning of 2015, with emphasis on the type of reactions catalyzed by metal phenolates that have gained more attention in the literature during this period.
Advances in Deposition of Metals from Metal Enolates
Authors: Lang Heinrich , Adner David , Georgi Colin
Published: April 2016

This chapter describes the use of metal enolates as precursors for the deposition and growth of nano‐sized materials of a large variety of metal, mixed metal‐metal oxide, and alloy layers and patterns, an area that has rapidly developed during the last couple of decades. As metal enolates, mostly mononuclear main group, transition metal, and rare earth metal complexes featuring various β‐diketonate or β‐ketoiminate ligands have been used. Based on their intrinsic properties, for example, reactivity, transparency, conductivity, and magnetism, a large variety of metal and/or metal oxide deposits are available at present. As deposition processes, mainly gas‐phase (e.g., CVD2–9 and ALD8–19) or liquid‐phase procedures (including spin‐coating, dip‐coating, sol–gel, and printing techniques) were used. Controlled decomposition of the appropriate metal enolates allows the generation of diverse metal and metal oxide materials, for example, dense or porous thin layers and nanomaterials in the form of particles, dots, rods, tubes, and wires. Where appropriate, the similarities and differences, including elementary decomposition steps that are common for the respective metal enolate precursors, are discussed as well.
Working Memory Capacity and Self‐Explanation Strategy Use Provide Additive Problem‐Solving Benefits
Authors: Redifer Jenni L. , Therriault David J. , Lee Christine S. , Schroeder Amber N.
Published: April 2016

The present study examined the impact of working memory capacity (WMC) on college students' ability to solve probability problems while using a self‐explanation strategy. Participants learned to solve probability problems in one of three conditions: a backward‐faded self‐explanation condition, an example problem pairs self‐explanation condition, or a control (no self‐explanation) condition. Even when accounting for the impact of WMC, learning to problem‐solve using self‐explanation led to superior problem‐solving performance. Conditions that prompted self‐explanation during problem‐solving resulted in significantly better problem‐solving performance than the control condition. These findings provide insight into the influence of individual differences on problem‐solving when strategies are provided, as well as information about the effectiveness of the self‐explanation strategy during mathematical problem‐solving. Copyright © 2016 John Wiley & Sons, Ltd.
Manipulation of Magnetic Properties by Oxygen Vacancies in Multiferroic YMnO3
Authors: Cheng Shaobo , Li Menglei , Deng Shiqing , Bao Shanyong , Tang Peizhe , Duan Wenhui , Ma Jing , Nan Cewen , Zhu Jing
Published: April 2016

Generating a single material with multiple ferroic properties has been the hotspot of research interest for decades. The existing studies mostly focus on the intrinsic properties of multiferroic materials, overlooking the importance of the widely distributed defects in the materials. Here, the strong influence of oxygen vacancies (V
O) on the magnetic properties of YMnO3 is demonstrated. The first‐principles calculations reveal that the V
O at axial positions can induce a nonzero net magnetization along the c‐axis. By structural characterization and magnetic measurement, this theoretically predicted ferromagnetic property is experimentally confirmed in the YMnO3 film grown on a c‐Al2O3 substrate. The large in‐plane compressive strain provided by the Al2O3 substrate allows to create the axial V
O of YMnO3 film in this system. The ferroelectricity of YMnO3 is also preserved even under large in‐plane compressive strain. Therefore, the coexistence of the ferroelectric and ferromagnetic properties can be realized in the YMnO3 film, which is of practical interest for technological applications.
Organic Cation‐Dependent Degradation Mechanism of Organotin Halide Perovskites
Authors: Wang Feng , Ma Jiale , Xie Fangyan , Li Linkai , Chen Jian , Fan Jun , Zhao Ni
Published: April 2016

The applications of organotin halide perovskites are limited because of their chemical instability under ambient conditions. Upon air exposure, Sn2+ can be rapidly oxidized to Sn4+, causing a large variation in the electronic properties. Here, the role of organic cations in degradation is investigated by comparing methylammonium tin iodide (MASnI3) and formamidinium tin iodide (FASnI3). Through chemical analyses and theoretical calculations, it is found that the organic cation strongly influences the oxidation of Sn2+ and the binding of H2O molecules to the perovskite lattice. On the one hand, Sn2+ can be easily oxidized to Sn4+ in MASnI3, and replacing MA with FA reduces the extent of Sn oxidation; on the other hand, FA forms a stronger hydrogen bond with H2O than does MA, leading to partial expansion of the perovskite network. The two processes compete in determining the material's conductivity. It is noted that the oxidation is a difficult process to prevent, while the water effect can be largely suppressed by reducing the moisture level. As a result, FASnI3‐based conductors and photovoltaic cells exhibit much better reproducibility as compared to MASnI3‐based devices. This study sheds light on the development of stable Pb‐free perovskite optoelectronic devices through new material design.
Synthesis and Functionalization of Oriented Metal–Organic‐Framework Nanosheets: Toward a Series of 2D Catalysts
Authors: Zhan Guowu , Zeng Hua Chun
Published: April 2016

Synthesis of metal–organic frameworks (MOFs) is based on coordination‐driven self‐assembly of metal ions and organic ligands. However, to date, it remains difficult to adjust the coordination behaviors of MOFs and then control geometric shapes of nanostructures; especially their morphologies in 1D nanofibers or 2D nanosheets have seldom been explored. Here, a facile route at room temperature and ambient pressure is reported for the preparation of copper‐based MOFs with low‐dimensional shapes (i.e., nanofibers, nanorods, nanosheets, and nanocuboids), via thermodynamic and kinetic controls over the anisotropic growth. Importantly, the as‐prepared 2D MOF nanosheets with monocrystalline nature (100% exposed {010} facets) provide a material platform to the fabrication of 2D supported metal nanocatalysts. First, the MOF nanosheets can serve as a self‐templating solid precursor to prepare different CuO and CuO‐Cu2O nanocomposites, or even Cu metals via thermolysis or reduction under controlled atmospheres. Upon their formation, second, ultrafine noble metal nanoparticles (e.g., Au, Ag, Pt, Pd, Au0.4Pt0.6, Au0.4Pd0.6, and Au0.3Pt0.3Pd0.4) can be exclusively anchored on the external surfaces of the MOF nanosheets. To show their open accessibility, catalytic activities of the derived catalysts have been evaluated using CO2 hydrogenation and 4‐nitrophenol reduction in gas phase and liquid phase, respectively.
High‐Performance Sodium‐Ion Hybrid Supercapacitor Based on Nb2O5@Carbon Core–Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites
Authors: Lim Eunho , Jo Changshin , Kim Min Su , Kim Mok‐Hwa , Chun Jinyoung , Kim Haegyeom , Park Jongnam , Roh Kwang Chul , Kang Kisuk , Yoon Songhun , Lee Jinwoo
Published: April 2016

Sodium‐ion hybrid supercapacitors (Na‐HSCs) have potential for mid‐ to large‐scale energy storage applications because of their high energy/power densities, long cycle life, and the low cost of sodium. However, one of the obstacles to developing Na‐HSCs is the imbalance of kinetics from different charge storage mechanisms between the sluggish faradaic anode and the rapid non‐faradaic capacitive cathode. Thus, to develop high‐power Na‐HSC anode materials, this paper presents the facile synthesis of nanocomposites comprising Nb2O5@Carbon core–shell nanoparticles (Nb2O5@C NPs) and reduced graphene oxide (rGO), and an analysis of their electrochemical performance with respect to various weight ratios of Nb2O5@C NPs to rGO (e.g., Nb2O5@C, Nb2O5@C/rGO‐70, ‐50, and ‐30). In a Na half‐cell configuration, the Nb2O5@C/rGO‐50 shows highly reversible capacity of ≈285 mA h g−1 at 0.025 A g−1 in the potential range of 0.01–3.0 V (vs Na/Na+). In addition, the Na‐HSC using the Nb2O5@C/rGO‐50 anode and activated carbon (MSP‐20) cathode delivers high energy/power densities (≈76 W h kg−1 and ≈20 800 W kg−1) with a stable cycle life in the potential range of 1.0–4.3 V. The energy and power densities of the Na‐HSC developed in this study are higher than those of similar Li‐ and Na‐HSCs previously reported.
Edge Functionalization of Graphene and Two‐Dimensional Covalent Organic Polymers for Energy Conversion and Storage
Authors: Xiang Zhonghua , Dai Quanbin , Chen Jian‐Feng , Dai Liming
Published: April 2016

Edge functionalization by selectively attaching chemical moieties at the edge of graphene sheets with minimal damage of the carbon basal plane can impart solubility, film‐forming capability, and electrocatalytic activity, while largely retaining the physicochemical properties of the pristine graphene. The resultant edge‐functionalized graphene materials (EFGs) are attractive for various potential applications. Here, a focused, concise review on the synthesis of EFGs is presented, along with their 2D covalent organic polymer (2D COP) analogues, as energy materials. The versatility of edge‐functionalization is revealed for producing tailor‐made graphene and COP materials for efficient energy conversion and storage.
3D Printing as Feasible Platform for On‐Site Building Oil‐Skimmer for Oil Collection from Spills
Authors: Yan Changyou , Ji Zhongying , Ma Shuanhong , Wang Xiaolong , Zhou Feng
Published: April 2016

Oil removal and collection from spills have been addressed by various techniques, but still remain a challenging topic for practical application because of high cost, low oil absorption capacity, and weak oil keeping stability. To address the challenge, an oil‐skimmer composed of 3D printed mesh cap treated with low surface energy materials and commercial vessel has been developed. The good water repellency of the 3D printed mesh realizes high efficient floating oil removal by filtration while the bottom vessel achieves the oil collection by storing the oil directly. Importantly, the collected oil does not escape from the vessel under ambitious stirring or reversion, indicating the skimmer's high potential application under the sea waves or even storm conditions. Taking the advantages of 3D printing in computer‐aid design and freeform fabrication, the feasible 3D printing oil‐skimmer is believed to be highly promising for the practical oil collection from spills in an on‐site design and fabrication manner.
Highly Effective Antiadhesive Coatings from pH‐Modified Water‐Dispersed Perfluorinated Acrylic Copolymers: The Case of Vulcanizing Rubber
Authors: Radaelli Greta , Heredia‐Guerrero José Alejandro , Masood Muhammad T. , Ceseracciu Luca , Davis Alexander , Carzino Riccardo , Prato Mirko , Bayer Ilker S. , Athanassiou Athanassia
Published: April 2016

A pH‐based method to tune the tribological and wetting properties of a coating obtained from water‐dispersed perfluorinated acrylic copolymer is demonstrated. The surface‐exposed fluorinated chains and chemical charges of the sprayed coatings can be controlled simply by tuning the pH of the initial water dispersion. The surface properties of the sprayed polymeric coatings remain unmodified when the pH of the water dispersion is reduced (addition of HCl). On the contrary, from dispersions with increased pH (addition of NaOH) a fluoroacrylic polyelectrolyte polymer is formed and clear variations in wetting and tribological properties of the polymeric coatings are observed. Interestingly, coatings' surface adhesion to vulcanizing rubber can be strongly reduced when the pH of the dispersions is in the range 4.5–6.0, which corresponds to a specific ratio between fluorinated chains and chemical charges. Consequently, such coatings can be proposed as low‐cost and easy‐to‐apply alternatives to aqueous release agents for the rubber tires demolding processes, thus having significant implications for the automotive tire industry.
Stable, Surfactant‐Free Graphene–Styrene Methylmethacrylate Composite for Ultrafast Lasers
Authors: Torrisi Felice , Popa Daniel , Milana Silvia , Jiang Zhe , Hasan Tawfique , Lidorikis Elefterios , Ferrari Andrea C.
Published: April 2016

Graphene–polymer composites play an increasing role in photonic and optoelectronic applications, from ultrafast pulse generation to solar cells. The fabrication of an optical quality surfactant‐free graphene‐styrene methyl methacrylate composite, stable to large humidity and temperature ranges is reported. The composite is tailored for photonic applications showing wavelength‐independent linear absorption in the visible and near‐infrared. When tested in a mode‐locked laser, it allows the generation of stable ≈326 fs mode‐locked pulses at 1550 nm, unperturbed by environmental conditions. The composite continues to operate as a saturable absorber even under complete water immersion at 60 °C. This confirms its stability against high‐temperature and humidity.
Guideline for Efficiency Enhancement in Semi‐Transparent Thin‐Film Organic Photovoltaics with Dielectric Mirrors
Authors: Bronnbauer Carina , Gasparini Nicola , Brabec Christoph J. , Forberich Karen
Published: April 2016

Semi‐transparent organic solar cells (ST‐OSCs) show a unique potential to be integrated in windows due to their outstanding characteristics such as high transparency and color‐adjustability. In order to achieve both, high transparency and high efficiency, the use of dielectric mirrors is an excellent concept. However, such a mirror will not only improve the photocurrent generated by a solar cell but also cause losses in transparency. In this work, a theoretical model is developed that predicts the effect of the dielectric mirror on the balance between photocurrent enhancement and transparency loss depending on the spectral shape of the ST‐OSC absorption. Experimental investigations with three fully printed ST‐OSCs showing different absorption characteristics underline the validity of these studies. It is concluded that ST‐OSCs with broad absorption spectra ranging from the short wavelength region over the visible to at least 950 nm are most suitable for the implementation of a dielectric mirror. A narrower absorption spectrum or a shift of the spectrum toward longer wavelengths makes an increase in photoactive layer thickness more beneficial than the attachment of a dielectric mirror. Moreover, the dielectric mirror approach is an excellent strategy to obtain high photocurrents for materials which cannot be processed at high active layer thicknesses.
Restricted Equilibrium Swelling of n‐Alkanes Posed by Ginger Spent Filled Polyurethane Green Composites during Sorption, Desorption, Resorption, and Redesorption Processes
Authors: Mahadevaiah Chethana ,   Siddaramaiah
Published: April 2016

Polyurethane (PU) based green composites with varying amounts of ginger spent (GS) have been fabricated and characterized for swelling and molecular transport behaviors in n‐alkane probe molecules. Sorption–desorption–resorption–redesorption (S‐D‐RS‐RD) behaviors have been performed to determine the true factor for transport coefficient. Sorption results are obtained by a gravimetric method and diffusion coefficient (D) has been calculated using Fick's equation for the linear data points of time‐dependent sorption/resorption curves. The observation was made that diffusion coefficient follows Fick's rule. Sorption studies have been carried out at 25, 40, and 60°C. A significant increase in sorption values has been noticed with raise in temperature. Sorption (S) and diffusion (D) coefficients of n‐alkanes depend on GS content in PU matrix. From the temperature dependence of diffusion and permeation (P) coefficients, the Arrhenius activation parameters have been used to estimate activation parameters such as diffusion (ED) and permeation (EP). Thermodynamic parameters such as enthalpy (ΔH) and entropy (ΔS) have been interpreted for sorption/resorption results. The percentage weight change for desoption and redesorption processes has been recorded; these results depend on the volatility of the penetrant molecules.
Near Infrared, Highly Efficient Luminescent Solar Concentrators
Authors: Zhou Yufeng , Benetti Daniele , Fan Zhiyuan , Zhao Haiguang , Ma Dongling , Govorov Alexander O. , Vomiero Alberto , Rosei Federico
Published: April 2016

The fabrication of a low reabsorption emission loss, high efficient luminescent solar concentrator (LSC) is demonstrated by embedding near infrared (NIR) core/shell quantum dots (QDs) in a polymer matrix. An engineered Stokes shift in NIR core/shell PbS/CdS QDs is achieved via a cation exchange approach by varying the core size and shell thickness through the refined reaction parameters such as reaction time, temperature, precursor molar ratio, etc. The as‐synthesized core/shell QDs with high quantum yield (QY) and excellent chemical/photostability exhibit a large Stokes shift with respect to the bare PbS QDs due to the strong core‐to‐shell electrons leakage. The large‐area planar LSC based on core/shell QDs exhibits the highest value (6.1% with a geometric factor of 10) for optical efficiency compared to the bare NIR QD‐based LSCs and other reported NIR QD‐based LSCs. The suppression of emission loss and the broad absorption of PbS/CdS QDs offer a promising pathway to integrate LSCs and photovoltaic devices with good spectral matching, indicating that the proposed core/shell QDs are strong candidates for fabricating high efficiency semi‐transparent large‐area LSCs.
Quality Choice and Market Access: Evidence from Chilean Wine Grape Production
Authors: Jano Pilar A.
Published: April 2016

This paper examines the determinants of becoming a producer of high‐quality wine grapes. We explore the case of wine‐grape farmers in Chile where we observe a bifurcation of farmer types.“Quasi‐subsistence” farmers produce traditional wine‐grape varieties and complement their subsistence income with cash coming from wine‐grape sale. On the other hand, we observe “entrepreneurial” farmers who produce classic varieties that have the potential to produce high‐quality wines. We study this bifurcation empirically using primary data collected during the 2011–2012 growing season. We find that wealth and cultivation ability provide economically and statistically significant explanatory power, but that buyer characteristics also matter. Our results suggest that a farmer's entry into the supply chain for high‐quality production is not an individual's choice. Rather it is a joint decision that cannot be fully understood without considering the objectives, incentives, and information of supplier and buyer. [EconLit citations: O14; Q140; L26].
Fast access to core/shell/shell CdTe/CdSe/ZnO quantum dots via magnetic hyperthermia method
Authors: Ling Luting , Wang Wei , Wang Cai‐Feng , Chen Su
Published: April 2016

The intrinsic low quantum yield (QY) of type II core shell quantum dots (QDs) composes the limitation for these heterostructured nanomaterials to be used in practical application. Herein, magnetic hyperthermia method is employed to intensify reaction process and facilely synthesize CdTe/CdSe heterostructured QDs with improved optical performance for the first time. The QY of the type II QDs is increased to 49% by further growing an inert ZnO layer. The type I interface between CdSe and ZnO helps confine electrons to the inner structure of the QDs, thus improving the QY. The successful preparation and performance enhancement of the CdTe/CdSe type II QDs via magnetic hyperthermia method demonstrate the great potential of this method for the preparation of other materials. Besides, the red‐emission QDs are used as conversion materials in white light emitting diodes to reveal their promising application in practical illumination. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2614–2621, 2016
Epidemiology and clinical relevance of mutations in postpolycythemia vera and postessential thrombocythemia myelofibrosis: A study on 359 patients of the AGIMM group
Authors: Rotunno Giada , Pacilli Annalisa , Artusi Valentina , Rumi Elisa , Maffioli Margherita , Delaini Federica , Brogi Giada , Fanelli Tiziana , Pancrazzi Alessandro , Pietra Daniela , Bernardis Isabella , Belotti Clara , Pieri Lisa , Sant'Antonio Emanuela , Salmoiraghi Silvia , Cilloni Daniela , Rambaldi Alessandro , Passamonti Francesco , Barbui Tiziano , Manfredini Rossella , Cazzola Mario , Tagliafico Enrico , Vannucchi Alessandro M. , Guglielmelli Paola
Published: April 2016

Transformation to secondary myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PPV‐MF) and essential thrombocythemia (PET‐MF). Although primary (PMF) and secondary MF are considered similar diseases and managed similarly, there are few studies specifically focused on the latter. The aim of this study was to characterize the mutation landscape, and describe the main clinical correlates and prognostic implications of mutations, in a series of 359 patients with PPV‐MF and PET‐MF. Compared with PV and ET, the JAK2V617F and CALR mutated allele burden was significantly higher in PPV‐MF and/or PET‐MF, indicating a role for accumulation of mutated alleles in the process of transformation to MF. However, neither the allele burden nor the type of driver mutation influenced overall survival (OS), while absence of any driver mutation (triple negativity) was associated with significant reduction of OS in PET‐MF, similar to PMF. Of the five interrogated subclonal mutations (ASXL1, EZH2, SRSF2, IDH1, and IDH2), that comprise a prognostically detrimental high molecular risk (HMR) category in PMF, only SRSF2 mutations were associated with reduced survival in PET‐MF, and no additional mutation profile with prognostic relevance was highlighted. Overall, these data indicate that the molecular landscape of secondary forms of MF is different from PMF, suggesting that unknown mutational events might contribute to the progression from chronic phase disease to myelofibrosis. These findings also support more extended genotyping approaches aimed at identifying novel molecular abnormalities with prognostic relevance for patients with PPV‐MF and PET‐MF. Am. J. Hematol. 91:681–686, 2016. © 2016 Wiley Periodicals, Inc.
Nutritional aspects of Noonan syndrome and Noonan‐related disorders
Authors: da Silva Fernanda Marchetto , Jorge Alexander Augusto , Malaquias Alexandra , da Costa Pereira Alexandre , Yamamoto Guilherme Lopes , Kim Chong Ae , Bertola Debora
Published: April 2016

Rasopathies are a group of rare disorders characterized by neurocardiofaciocutaneous involvement, and caused by mutations in several genes of the RAS/MAPK pathway. In the present study, we characterized growth parameters, body composition, and nutritional aspects of children and adults (n = 62) affected by these disorders, mainly Noonan syndrome, using an indirect method—anthropometry—and a 24‐hr recall questionnaire. The growth parameters in our cohort showed short stature, especially in individuals with RAF1 and SHOC2 mutations, lower obesity rates compared to the control population, and BMI scores highest in individuals with BRAF mutations and lowest in individuals with SHOC2. Body composition showed a compromise in the upper arm muscle circumference, with a statistically significant difference in the z‐score of triceps skinfold (P = 0.0204) and upper arm fat area (P = 0.0388) between BRAF and SHOC2 groups and in the z‐score of triceps skinfold between RAF1 and SHOC2 (P = 0.0218). The pattern of macronutrient consumption was similar to the control population. Our study is the first to address body composition in RASopathy individuals and the data indicate a compromise not only in adipose tissue, but also in muscle mass. Studies using different techniques, such as dual‐energy X‐ray absorptiometry or imaging studies, which give a more precise delineation of fat and non‐fat mass, are required to confirm our results, ultimately causing an impact on management strategies. © 2016 Wiley Periodicals, Inc.
Solvent‐Free Pot‐, Atom‐ and Step‐Economic Synthesis of Novel Benzo[d]thiazole‐[1,3]‐thiazine Hybrids in a One‐Pot Reaction
Authors: Wadhwa Preeti , Kaur Tanpreet , Sharma Anuj
Published: April 2016

The first catalyst‐ and solvent‐free synthesis of novel benzo[d]thiazole‐[1,3]‐thiazine hybrids from benzo[d]thiazol‐2‐amines, isothiocyanates and dialkyl acetylenedicarboxylates with no more than 30 min of microwave irradiation is described. Moreover, the proposed strategy involves neither tedious workup nor column purification steps. This approach provides a diversity‐oriented route for the rapid assembly of benzo[d]thiazole‐[1,3]‐thiazine frameworks. Furthermore, the methodology has excellent green credentials, scoring well in a number of green metrics, hence showing this approach to be an ideal green and sustainable process.
Bound states and Cooper pairs of molecules in 2D optical lattices bilayer
Authors: Camacho‐Guardian A. , Domínguez‐Castro G. A. , Paredes R.
Published: April 2016

We investigate the formation of Cooper pairs, bound dimers and the dimer‐dimer elastic scattering of ultracold dipolar Fermi molecules confined in a 2D optical lattice bilayer configuration. While the energy and their associated bound states are determined in a variational way, the correlated two‐molecule pair is addressed as in the original Cooper formulation. We demonstrate that the 2D lattice confinement favors the formation of zero center mass momentum bound states. Regarding the Cooper pairs binding energy, this depends on the molecule populations in each layer. Maximum binding energies occur for non‐zero (zero) pair momentum when the Fermi system is polarized (unpolarized). We find an analytic expression for the dimer‐dimer effective interaction in the deep BEC regime. The present analysis represents a route for addressing the BCS‐BEC crossover in dipolar Fermi gases confined in 2D optical lattices within the current experimental panorama.
Nonlinear optical characteristics of monolayer MoSe2
Authors: Le Chinh Tam , Clark Daniel J. , Ullah Farman , Senthilkumar Velusamy , Jang Joon I. , Sim Yumin , Seong Maeng‐Je , Chung Koo‐Hyun , Park Hyoyeol , Kim Yong Soo
Published: April 2016

In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe2. Two‐step growth involving the selenization of pulsed‐laser‐deposited MoO3 film was employed to yield the MoSe2 monolayer on a SiO2/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second‐order susceptibility χ(2) was calculated to be ∼50 pm V−1 at the second harmonic wavelength ∼810 nm, which is near the optical gap of the monolayer. Interestingly, our wavelength‐dependent second harmonic scan can identify the bound excitonic states including negatively charged excitons much more efficiently, compared with the PL method at room temperature. Additionally, the MoSe2 monolayer exhibits a strong laser‐induced damage threshold ∼16 GW cm−2 under picosecond‐pulse excitation. Our findings suggest that monolayer MoSe2 can be considered as a promising candidate for high‐power, thin‐film‐based nonlinear optical devices and applications.
Functionalization of Two‐Dimensional MoS2: On the Reaction Between MoS2 and Organic Thiols
Authors: Chen Xin , Berner Nina C. , Backes Claudia , Duesberg Georg S. , McDonald Aidan R.
Published: April 2016

Two‐dimensional layered transition metal dichalcogenides (TMDs) have attracted great interest owing to their unique properties and a wide array of potential applications. However, due to their inert nature, pristine TMDs are very challenging to functionalize. We demonstrate a general route to functionalize exfoliated 2H‐MoS2 with cysteine. Critically, MoS2 was found to be facilitating the oxidation of the thiol cysteine to the disulfide cystine during functionalization. The resulting cystine was physisorbed on MoS2 rather than coordinated as a thiol (cysteine) filling S‐vacancies in the 2H‐MoS2 surface, as originally conceived. These observations were found to be true for other organic thiols and indeed other TMDs. Our findings suggest that functionalization of two‐dimensional MoS2 using organic thiols may not yield covalently or datively tethered functionalities, rather, in this instance, they yield physisorbed disulfides that are easily removed.
Insights Into the Allosteric Inhibition of the SUMO E2 Enzyme Ubc9
Authors: Hewitt William M. , Lountos George T. , Zlotkowski Katherine , Dahlhauser Samuel D. , Saunders Lindsey B. , Needle Danielle , Tropea Joseph E. , Zhan Chendi , Wei Guanghong , Ma Buyong , Nussinov Ruth , Waugh David S. , Schneekloth John S.
Published: April 2016

Conjugation of the small ubiquitin‐like modifier (SUMO) to protein substrates is an important disease‐associated posttranslational modification, although few inhibitors of this process are known. Herein, we report the discovery of an allosteric small‐molecule binding site on Ubc9, the sole SUMO E2 enzyme. An X‐ray crystallographic screen was used to identify two distinct small‐molecule fragments that bind to Ubc9 at a site distal to its catalytic cysteine. These fragments and related compounds inhibit SUMO conjugation in biochemical assays with potencies of 1.9–5.8 mm. Mechanistic and biophysical analyses, coupled with molecular dynamics simulations, point toward ligand‐induced rigidification of Ubc9 as a mechanism of inhibition.
Unraveling Epitaxial Habits in the NaLnF4 System for Color Multiplexing at the Single‐Particle Level
Authors: Zhang Yuhai , Huang Ling , Liu Xiaogang
Published: April 2016

We report an epitaxial growth technique for scalable production of hybrid sodium rare‐earth fluoride (NaLnF4) microcrystals, including NaYF4, NaYbF4, and NaLuF4 material systems. The single crystalline nature of the as‐synthesized products makes them strong upconversion emission. The freedom of combining a lanthanide activator (Er3+ or Tm3+) with a sensitizer (Yb3+) at various doping concentrations readily gives access to color multiplexing at the single‐particle level. Our kinetic and thermodynamic investigations on the epitaxial growth of core–shell microcrystals using NaLnF4 particle seeds suggest that within a certain size regime it is plausible to exert precise control over shell thickness and growth orientation under hydrothermal conditions.
Mono‐ und ditope Bisfunktionalisierung von Graphen
Authors: Knirsch Kathrin C. , Schäfer Ricarda A. , Hauke Frank , Hirsch Andreas
Published: April 2016

Wir berichten zum ersten Mal über die Bisfunktionalisierung von Graphen auf der Basis zweier konsekutiver Reduktions‐ und kovalenter Additionsschritte. Dieser Ansatz wurde sowohl für die lösungsmittelbasierte Funktionalisierung von Graphen im präparativen Maßstab als auch für die Derivatisierung individueller Kohlenstofflagen auf Oberflächen genutzt. Im ersten Fall ist der elektrophile Angriff aus beiden Halbräumen der Basalebene möglich, was zum Aufbau spannungsfreier Architekturen führt. Im zweiten Fall hingegen gewinnen Retrofunktionalisierungsreaktionen an Bedeutung, insbesondere wenn das entsprechende Anion des Erstaddenden eine gute Abgangsgruppe darstellt.
Nonpeptidic Selective Inhibitors of the Chymotrypsin‐Like (β5 i) Subunit of the Immunoproteasome
Authors: Sosič Izidor , Gobec Martina , Brus Boris , Knez Damijan , Živec Matej , Konc Janez , Lešnik Samo , Ogrizek Mitja , Obreza Aleš , Žigon Dušan , Janežič Dušanka , Mlinarič‐Raščan Irena , Gobec Stanislav
Published: April 2016

Elevated expression of the immunoproteasome has been associated with autoimmune diseases, inflammatory diseases, and various types of cancer. Selective inhibitors of the immunoproteasome are not only scarce, but also almost entirely restricted to peptide‐based compounds. Herein, we describe nonpeptidic reversible inhibitors that selectively block the chymotrypsin‐like (β5i) subunit of the human immunoproteasome in the low micromolar range. The most potent of the reversibly acting compounds were then converted into covalent, irreversible, nonpeptidic inhibitors that retained selectivity for the β5i subunit. In addition, these inhibitors discriminate between the immunoproteasome and the constitutive proteasome in cell‐based assays. Along with their lack of cytotoxicity, these data point to these nonpeptidic compounds being suitable for further investigation as β5i‐selective probes for possible application in noncancer diseases related to the immunoproteasome.
Astellifadiene: Structure Determination by NMR Spectroscopy and Crystalline Sponge Method, and Elucidation of its Biosynthesis
Authors: Matsuda Yudai , Mitsuhashi Takaaki , Lee Shoukou , Hoshino Manabu , Mori Takahiro , Okada Masahiro , Zhang Huiping , Hayashi Fumiaki , Fujita Makoto , Abe Ikuro
Published: April 2016

Genome mining of a terpene synthase gene from Emericella variecolor NBRC 32302 and its functional expression in Aspergillus oryzae led to the production of the new sesterterpene hydrocarbon, astellifadiene (1), having a 6‐8‐6‐5‐fused ring system. The structure of 1 was initially investigated by extensive NMR analyses, and was further confirmed by the crystalline sponge method, which established the absolute structure of 1 and demonstrated the usefulness of the method in the structure determination of complex hydrocarbon natural products. Furthermore, the biosynthesis of 1 was proposed on the basis of isotope‐incorporation experiments performed both in vivo and in vitro. The cyclization of GFPP involves a protonation‐initiated second cyclization sequence, 1,2‐alkyl migration, and 1,5‐hydride shift to generate the novel scaffold of 1.
Triply Linked Corrole Dimers
Authors: Ooi Shota , Tanaka Takayuki , Park Kyu Hyung , Kim Dongho , Osuka Atsuhiro
Published: April 2016

The oxidation of 10–10′ singly linked corrole dimers with DDQ at low concentration in CHCl3 afforded meso–meso, β–β, β–β triply linked 2H‐corrole dimers (with two inner NH groups in each corrole unit), which exhibited characteristic 1H NMR and absorption spectra attributable to their nonaromatic electronic networks. These 2H‐corrole dimers were reduced with NaBH4 to aromatic 3H‐corrole dimers, which were unstable and easily oxidized back to the 2H‐corrole dimers upon exposure to air. Bis(zinc(II)) complexes of the 2H‐corrole dimers were synthesized and characterized as rare examples of nonaromatic zinc(II) corrole complexes.
Mono‐ and Ditopic Bisfunctionalization of Graphene
Authors: Knirsch Kathrin C. , Schäfer Ricarda A. , Hauke Frank , Hirsch Andreas
Published: April 2016

For the first time, the bisfunctionalization of graphene by employing two successive reduction and covalent bond forming steps is reported. Bulk functionalization in dispersion and functionalization of individual sheets deposited on surfaces have both been carried out. Whereas in the former case attacks from both sides of the basal plane are possible and can lead to strain‐free architectures, in the latter case, retrofunctionalizations can become important when the corresponding anion of the addend is a sufficiently good leaving group.
π‐Extended “Earring” Porphyrins with Multiple Cavities and Near‐Infrared Absorption
Authors: Rao Yutao , Kim Taeyeon , Park Kyu Hyung , Peng Fulei , Liu Lei , Liu Yunmei , Wen Bin , Liu Shubin , Kirk Steven Robert , Wu Licheng , Chen Bo , Ma Ming , Zhou Mingbo , Yin Bangshao , Zhang Yuexing , Kim Dongho , Song Jianxin
Published: April 2016

β,β‐tripyrrin‐bridged earring porphyrins were synthesized through Suzuki–Miyaura cross coupling reactions. These porphyrinoids have multiple cavities and can accommodate two or three metal ions per molecule. The structures of the porphyrins have been elucidated by x‐ray diffraction analysis, and feature curved π planes. The electronic spectra of the porphyrins exhibit near‐infrared (NIR) absorptions and metal insertion leads to red‐shifted and intensified absorption features. Electrochemical analysis and transient absorption measurements indicated that the porphyrins exhibit effective electronic communication between their central and peripheral moieties.
Effect of unfunctionalized and HNO3‐functionalized MWCNT on the mechanical and electrical performances of PEMFC bipolar plates
Authors: Athmouni Nafaa , Mighri Frej , Elkoun Saïd
Published: April 2016

This study aims at developing lightweight and high performance electrically conductive nanocomposites for proton exchange membrane fuel cell (PEMFC) bipolar plates (BPPs). These composites were made from an optimized co‐continuous mixture of Polyethylene terephthalate (PET) and polyvinylidene fluoride (PVDF) reinforced with highly conductive carbon additives composed of carbon black (CB) and synthetic graphite (GR). Multiwall carbon nanotubes (MWCNT) were functionalized then used to improve BPPs electrical conductivity and their mechanical properties, such as flexural and impact strengths. It was observed that the best BPP prototype was obtained using nitric acid (HNO3)‐functionalized MWCNT. The latter led to the smothest BPP surface, the lowest through‐plane resitivity (0.12 Ω cm) and the highest impact and flexural strengths. These results are attributed to the improved dispersion of the functionalized MWCNT, a result of their best compatibilization with the (PET/PVDF) polymeric phase. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43624.