bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Biomass Burning Plumes on Photolysis Rates and Ozone Formation at the Mount Bachelor Observatory
Authors: Baylon P. , Jaffe D. A. , Hall S. R. , Ullmann K. , Alvarado M. J. , Lefer B. L. 
Published: February 2018

AbstractIn this paper, we examine biomass burning (BB) events at the Mt. Bachelor Observatory (MBO) during the summer of 2015. We explored the photochemical environment in these BB plumes, which remains poorly understood. Because we are interested in understanding the effect of aerosols only (as opposed to the combined effect of aerosols and clouds), we carefully selected three cloud‐free days in August and investigate the photochemistry in these plumes. At local midday (solar zenith angle (SZA) = 35°),j(NO2) values were slightly higher (0.2–1.8%) in the smoky days compared to the smoke‐free day, presumably due to enhanced scattering by the smoke aerosols. At higher SZA (70°), BB aerosols decreasej(NO2) by 14–21%. We also observe a greater decrease in the actinic flux at 310–350 nm, compared to 360–420 nm, presumably due to absorption in the UV by brown carbon. We compare our measurements with results from the Tropospheric Ultraviolet‐Visible v.5.2 model. As expected, we find a good agreement (to within 6%) during cloud‐free conditions. Finally, we use the extended Leighton relationship and a photochemical model (Aerosol Simulation Program v.2.1) to estimate midday HO2and RO2concentrations and ozone production rates (P(O3)) in the fire plumes. We observe that Leighton‐derived HO2and RO2values (49–185 pptv) and instantaneousP(O3) (2.0–3.6 ppbv/h) are higher than the results from the photochemical model.
On the Utility (or Futility) of Using Stable Water Isotopes to Constrain the Bulk Properties of Tropical Convection
Authors: Duan Suqin Q. , Wright Jonathon S. , Romps David M. 
Published: February 2018

AbstractAtmospheric water‐vapor isotopes have been proposed as a potentially powerful constraint on convection, which plays a critical role in Earth's present and future climate. It is shown here, however, that the mean tropical profile of HDO in the free troposphere does not usefully constrain the mean convective entrainment rate or precipitation efficiency. This is demonstrated using a single‐column analytical model of atmospheric water isotopes. The model has three parameters: the entrainment rate, the precipitation efficiency, and the distance that evaporating condensates fall. At a given relative humidity, the possible range of HDO is small: its range is comparable to both the measurement uncertainty in the mean tropical profile and the structural uncertainty of a single‐column model. Therefore, the mean tropical HDO profile is unlikely to add information about convective processes in a bulk‐plume framework that cannot already be learned from relative humidity alone.
Global Effects of Superparameterization on Hydrothermal Land‐Atmosphere Coupling on Multiple Timescales
Authors: Qin Hongchen , Pritchard Michael S. , Kooperman Gabriel J. , Parishani Hossein 
Published: February 2018

AbstractMany conventional General Circulation Models (GCMs) in the Global Land‐Atmosphere Coupling Experiment (GLACE) tend to produce what is now recognized as overly strong land‐atmosphere (L‐A) coupling. We investigate the effects of cloud Superparameterization (SP) on L‐A coupling on timescales beyond diurnal where it has been recently shown to have a favorable muting effect hydrologically. Using the Community Atmosphere Model v3.5 (CAM3.5) and its Superparameterized counterpart SPCAM3.5, we conducted soil moisture interference experiments following the GLACE and Atmospheric Model Intercomparison Project (AMIP) protocols. The results show that, on weekly‐to‐subseasonal timescales, SP also mutes hydrologic L‐A coupling. This is detectable globally, and happens through the evapotranspiration‐precipitation segment. But on seasonal timescales, SP does not exhibit detectable effects on hydrologic L‐A coupling. Two robust regional effects of SP on thermal L‐A coupling have also been explored. Over the Arabian Peninsula, SP reduces thermal L‐A coupling through a straightforward control by mean rainfall reduction. More counterintuitively, over the Southwestern US and Northern Mexico, SP enhances the thermal L‐A coupling in a way that is independent of rainfall and soil moisture. This signal is associated with a systematic and previously unrecognized effect of SP that produces an amplified Bowen ratio, and is detectable in multiple SP model versions and experiment designs. In addition to amplifying the present‐day Bowen ratio, SP is found to amplify the climate sensitivity of Bowen ratio as well, which likely plays a role in influencing climate change predictions at the L‐A interface.
Assessment of multi‐criteria optimization (MCO) for volumetric modulated arc therapy (VMAT) in hippocampal avoidance whole brain radiation therapy (HA‐WBRT)
Authors: Zieminski Stephen , Khandekar Melin , Wang Yi 
Published: February 2018

AbstractThis study compared the dosimetric performance of (a) volumetric modulated arc therapy (VMAT) with standard optimization (STD) and (b) multi‐criteria optimization (MCO) to (c) intensity modulated radiation therapy (IMRT) with MCO for hippocampal avoidance whole brain radiation therapy (HA‐WBRT) in RayStation treatment planning system (TPS). Ten HA‐WBRT patients previously treated with MCO‐IMRT or MCO‐VMAT on an Elekta Infinity accelerator with Agility multileaf collimators (5‐mm leaves) were re‐planned for the other two modalities. All patients received 30 Gy in 15 fractions to the planning target volume (PTV), namely, PTV30 expanded with a 2‐mm margin from the whole brain excluding hippocampus with margin. The patients all had metastatic lesions (up to 12) of variable sizes and proximity to the hippocampus, treated with an additional 7.5 Gy from a simultaneous integrated boost (SIB) to PTV37.5. The IMRT plans used eight to eleven non‐coplanar fields, whereas the VMAT plans used two coplanar full arcs and a vertex half arc. The averaged target coverage, dose to organs‐at‐risk (OARs) and monitor unit provided by the three modalities were compared, and a Wilcoxon signed‐rank test was performed. MCO‐VMAT provided statistically significant reduction of D100 of hippocampus compared to STD‐VMAT, and Dmax of cochleas compared to MCO‐IMRT. With statistical significance, MCO‐VMAT improved V30 of PTV30 by 14.2% and 4.8%, respectively, compared to MCO‐IMRT and STD‐VMAT. It also raised D95 of PTV37.5 by 0.4 Gy compared to both MCO‐IMRT and STD‐VMAT. Improved plan quality parameters such as a decrease in overall plan Dmax and total monitor units (MU) were also observed for MCO‐VMAT. MCO‐VMAT is found to be the optimal modality for HA‐WBRT in terms of PTV coverage, OAR sparing and delivery efficiency, compared to MCO‐IMRT or STD‐VMAT.
Anchoring and Upgrading Ultrafine NiPd on Room‐Temperature‐Synthesized Bifunctional NH2‐N‐rGO toward Low‐Cost and Highly Efficient Catalysts for Selective Formic Acid Dehydrogenation
Authors: Yan Jun‐Min , Li Si‐Jia , Yi Sha‐Sha , Wulan Ba‐Ri , Zheng Wei‐Tao , Jiang Qing 
Published: February 2018

AbstractHydrogen is widely considered to be a sustainable and clean energy alternative to the use of fossil fuels in the future. Its high hydrogen content, nontoxicity, and liquid state at room temperature make formic acid a promising hydrogen carrier. Designing highly efficient and low‐cost heterogeneous catalysts is a major challenge for realizing the practical application of formic acid in the fuel‐cell‐based hydrogen economy. Herein, a simple but effective and rapid strategy is proposed, which demonstrates the synthesis of NiPd bimetallic ultrafine particles (UPs) supported on NH2‐functionalized and N‐doped reduced graphene oxide (NH2‐N‐rGO) at room temperature. The introduction of the NH2N group to rGO is the key reason for the formation of the ultrafine and well‐dispersed Ni0.4Pd0.6 UPs (1.8 nm) with relatively large surface area and more active sites. Surprisingly, the as‐prepared low‐cost NiPd/NH2‐N‐rGO dsiplays excellent hydrophilicity, 100% H2 selectivity, 100% conversion, and remarkable catalytic activity (up to 954.3 mol H2 (mol catalyst)−1 h−1) for FA decomposition at room temperature even with no additive, which is much higher than that of the best catalysts so far reported.
N‐(Acyloxy)phthalimides as Redox‐Active Esters in Cross‐Coupling Reactions
Authors: Murarka Sandip 
Published: February 2018

AbstractRecent years have witnessed a resurgence of novel, efficient and practical protocols for radical‐mediated cross‐coupling reactions involving N‐(acyloxy)phthalimides (NHPI esters) as redox‐active esters. After the initial discovery of the redox‐active properties of NHPI esters, exciting examples of SET‐based cross‐coupling reactions under thermal or photolytic conditions leading to diverse C–X (X=C, B, Si, Se, S) bonds have been published. The operational simplicity and broad applicability exhibited in redox‐active NHPI ester‐based cross‐couplings bode well for their widespread adoption. The review presented herein covers all the recent developments in the field of redox‐active ester (RAE)‐based cross‐couplings since the initial discovery. Depending on the conditions employed the reactions have been categorized into photoinduced and non‐photoinduced cross‐couplings with representative examples and insightful mechanistic discussions.magnified image
Designing Nonpolar Metallic Interfaces using Insulating Transition Metal Olivine Phosphates
Authors: Jena Ajit , Murali Devaraj , Nanda Birabar Ranjit Kumar 
Published: February 2018

AbstractThrough density functional calculations, we have demonstrated that ferromagnetic and metallic (FM‐M) phase can be tailored in superlattices consisting of two dissimilar antiferromagnetic and insulating olivine phosphates LiMPO4 and LiMʹPO4 where M and Mʹ are 3d transition metals. The proposed tailored superlattices are stable and differ from the regular superlattices through broken and missing PO4 tetrahedra. As a result, the p–d covalent bondings become reasonable and transition metal ions are forced to stabilize in fractional charge state instead of the integer‐charge state observed in bulk. These result in partially occupied parabolic dispersive bands to favor the metallic phase and therefore open up the possibilities to go beyond the conventional layered perovskite polar interfaces to create metallic heterostructures out of insulating oxides. Out of all M‐Mʹ combinations, we find that Cr‐Mn, Cr‐Co, Cr‐Ni, Mn‐Co and Mn‐Ni combinations yield the FM‐M phase as ground state in the tailored superlattices.
NIR‐Triggered Crystal Phase Transformation of NiTi‐Layered Double Hydroxides Films for Localized Chemothermal Tumor Therapy
Authors: Wang Donghui , Ge Naijian , Yang Tingting , Peng Feng , Qiao Yuqin , Li Qianwen , Liu Xuanyong 
Published: February 2018

AbstractConstruction of localized drug‐eluting systems with synergistic chemothermal tumor‐killing abilities is promising for biomedical implants directly contacting with tumor tissues. In this study, an intelligent and biocompatible drug‐loading platform, based on a gold nanorods‐modified butyrate‐inserted NiTi‐layered double hydroxides film (Au@LDH/B), is prepared on the surface of nitinol alloy. The prepared films function as drug‐loading “sponges,” which pump butyrate out under near‐infrared (NIR) irradiation and resorb drugs in water when the NIR laser is shut off. The stimuli‐responsive release of butyrate is verified to be related with the NIR‐triggered crystal phase transformation of Au@LDH/B. In vitro and in vivo studies reveal that the prepared films possess excellent biosafety and high efficiency in synergistic thermochemo tumor therapy, showing a promising application in the construction of localized stimuli‐responsive drug‐delivery systems.
Chronic myeloid leukemia: 2018 update on diagnosis, therapy and monitoring
Authors: Jabbour Elias , Kantarjian Hagop 
Published: February 2018

AbstractDisease overviewChronic myeloid leukemia (CML) is a myeloproliferative neoplasm with an incidence of 1‐2 cases per 100 000 adults. It accounts for approximately 15% of newly diagnosed cases of leukemia in adults.DiagnosisCML is characterized by a balanced genetic translocation, t(9;22)(q34;q11.2), involving a fusion of the Abelson gene (ABL1) from chromosome 9q34 with the breakpoint cluster region (BCR) gene on chromosome 22q11.2. This rearrangement is known as the Philadelphia chromosome. The molecular consequence of this translocation is the generation of a BCR‐ABL1 fusion oncogene, which in turn translates into a BCR‐ABL1 oncoprotein.Frontline therapy: Four tyrosine kinase inhibitors (TKIs), imatinib, nilotinib, dasatinib, and bosutinib are approved by the United States Food and Drug Administration for first‐line treatment of patients with newly diagnosed CML in chronic phase (CML‐CP). Clinical trials with second generation TKIs reported significantly deeper and faster responses; this has not translated into improved long‐term survival, because of the availability of effective salvage therapies.Salvage therapy: For patients who fail frontline therapy, second‐line options include second and third generation TKIs. Second and third generation TKIs, although potent and selective, exhibit unique pharmacological profiles and response patterns relative to different patient and disease characteristics, such as patients’ comorbidities, disease stage, and BCR‐ABL1 mutational status. Patients who develop the T315I “gatekeeper” mutation display resistance to all currently available TKIs except ponatinib. Allogeneic stem cell transplantation remains an important therapeutic option for patients with CML‐CP who have failed at least 2 TKIs, and for all patients in CML advanced phases.
Local‐Curvature‐Controlled Non‐Epitaxial Growth of Hierarchical Nanostructures
Authors: Li Chaoran , Zhang Shumin , Zhang Bingchang , Liu Jingjing , Zhang Weihu , Solovev Alexander A. , Tang Rujun , Bao Feng , Yu Jia , Zhang Qiao , Lifshitz Yeshayahu , He Le , Zhang Xiaohong 
Published: February 2018

AbstractSite‐selective growth on non‐spherical seeds provides an indispensable route to hierarchical complex nanostructures that are interesting for diverse applications. However, this has only been achieved through epitaxial growth, which is restricted to crystalline materials with similar crystal structures and physicochemical properties. A non‐epitaxial growth strategy is reported for hierarchical nanostructures, where site‐selective growth is controlled by the curvature of non‐spherical seeds. This strategy is effective for site‐selective growth of silica nanorods from non‐spherical seeds of different shapes and materials, such as α‐Fe2O3, NaYF4, and ZnO. This growth strategy is not limited by the stringent requirements of epitaxy and is thus a versatile general method suitable for the preparation of hierarchical nanostructures with controlled morphologies and compositions to open up a verity of applications in self‐assembly, nanorobotics, catalysis, electronics, and biotechnology.
GMA‐based emulsion‐templated solid foams: Influence of co‐crosslinker on morphology and mechanical properties
Authors: Rezanavaz Roya , Fee Conan J. , Dimartino Simone 
Published: February 2018

ABSTRACTHighly open porous polymer foams formed from high internal phase emulsions (polyHIPEs) are attracting significant interest because of their potential applications in many areas of advanced materials science. In this work, the influence of the crosslinker or co‐crosslinkers of different molecular weights on the morphology and mechanical properties of polyHIPEs containing glycidyl methacrylate (GMA) was studied. Several poly(ethylene glycol) dimethacrylate (PEGDMA) crosslinkers were considered. The results show that introducing higher molecular weight crosslinkers into polyHIPEs produces a more open structure, with significantly increased compression strength and deformation at breakage. This eliminated the undesirable brittleness and chalkiness commonly found in polyHIPE materials. The Young's modulus of GMA‐based polyHIPEs containing 40% poly(ethylene glycol) dimethacrylate increased by 50% and the crush strength by 400% when compared with traditional GMA/ethylene glycol dimethylacrylate polyHIPEs. This improvement in mechanical properties is expected to improve the suitability of polyHIPEs for use in a wide range of applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46295.
Transformation of a Pt–CeO2 Mechanical Mixture of Pulsed‐Laser‐Ablated Nanoparticles to a Highly Active Catalyst for Carbon Monoxide Oxidation
Authors: Slavinskaya E. M. , Stadnichenko A. I. , Muravyov V. V. , Kardash T. Y. , Derevyannikova E. A. , Zaikovskii V. I. , Stonkus O. A. , Lapin I. N. , Svetlichnyi V. A. , Boronin A. I. 
Published: February 2018

AbstractThe pulsed laser ablation (PLA) in alcohol and water media was employed to prepare Pt and CeO2 PLA‐nanoparticles of different sizes and degrees of defectiveness. Interactions of metallic platinum and ceria particles were studied using the thermal activation of Pt–CeO2 mechanical mixtures in the CO+O2 reaction medium or O2 atmosphere. The thermal activation resulted in oxidized Pt2+/Pt4+ states of platinum in the surface solid solutions PtCeOx and/or PtOx clusters. Catalysts formed after calcination of the PLA‐ablated Pt–CeO2 mixtures in oxygen at 450–600 °C revealed CO conversion at very low temperatures up to 70 % depending on the conditions of PLA particles preparation and thermal activation of Pt–CeO2 mechanical mixture.
New Phosphorus‐Doped Perovskite Oxide as an Oxygen Reduction Reaction Electrocatalyst in an Alkaline Solution
Authors: Shen Yujuan , Zhu Yinlong , Sunarso Jaka , Guan Daqin , Liu Bo , Liu Hong , Zhou Wei , Shao Zongping 
Published: February 2018

AbstractBecause of their structural and compositional flexibility, perovskite oxides represent an attractive alternative electrocatalyst class to precious metals for the oxygen reduction reaction (ORR); an important reaction in fuel cells and metal–air batteries. Partial replacement of the original metal cation with another cation, namely, doping, can be used to tailor the ORR activity of perovskite, for which a metal has been exclusively used as the dopant component in the past. Herein, phosphorus is proposed as a non‐metal dopant for the cation site to develop a new perovskite family with the formula of La0.8Sr0.2Mn1−xPxO3−δ (x=0, 0.02, 0.05, and 0.1; denoted as LSM, LSMP0.02, LSMP0.05, and LSMP0.1, respectively). Powder XRD patterns reveal that the solubility of phosphorus in the perovskite structure is around 0.05. Rotating ring‐disk electrode experiments in the form of linear‐sweep voltammetry scans demonstrated the best ORR performance for LSMP0.05, and also revealed close to a four‐electron ORR pathway for all four compositions. A chronoamperometric test (9000 s) and 500 cycle accelerated durability test demonstrated higher durability for LSMP0.05 relative to that of LSM and the commercial 20 wt % Pt/C catalyst. The higher ORR activity for LSMP0.05 is attributed to the optimised average valence of Mn, as evidenced by combined X‐ray photoelectron spectroscopy and soft X‐ray absorption spectroscopy data. Doping phosphorus into perovskites is an effective way to develop high‐performance electrocatalysts for ORR.
Mechanistic Exploration of the Transmetalation and Reductive Elimination Events Involving PdIV–Abnormal NHC Complexes in Suzuki–Miyaura Coupling Reactions: A DFT Study
Authors: Mondal Totan , De Sriman , Dutta Sayan , Koley Debasis 
Published: February 2018

AbstractA comprehensive DFT (M06‐L‐D3(SMD)/BS2//M06‐L/BS1 level) investigation has been carried out to explore in detail the mechanism of the transmetalation and reductive elimination reactions of abnormal N‐heterocyclic carbene (aNHC) palladium(IV) complexes within the framework of Suzuki–Miyaura cross‐coupling reactions. Emphasis was placed on the role of base and the effect of countercations on the critical transmetalation and reductive elimination events involving palladium(IV) complexes. Of the two competing roles of the base, the route involving boronate formation followed by halide exchange prevails over that of direct halide exchange for the intermediates [PdIV(aNHC)(OMe)2Cl]−Na+ (pathway A), [PdIV(aNHC)(OMe)(Cl)2]−Na+ (pathway B), and [PdIV(aNHC)Cl3]−Na+ (pathway C) emanating from the oxidative addition reaction. The results of the calculations are in accordance with our previous theoretical findings of favorable energetics for palladium intermediates incorporating two coordinated methoxy groups. The negative role played by the countercation in the transmetalation step is mainly due to the overstabilization of the pre‐transmetalation intermediate, which is in line with experimental kinetic results. The anionic complexes exhibit greater affinity for the transmetalation and reductive elimination reactions than the neutral variants.
Selectivity Modulation and Structure of α/aza‐β3 Cyclic Antimicrobial Peptides
Authors: Laurencin Mathieu , Simon Matthieu , Fleury Yannick , Baudy‐Floc'h Michèle , Bondon Arnaud , Legrand Baptiste 
Published: February 2018

AbstractPotent and selective antimicrobial cyclic pseudopeptides (ACPPs) mixing α‐ and aza‐β3‐amino acids were developed. Cyclopseudopeptide sequences were designed to investigate the impact of some intrinsic molecular parameters on their biological activities. Fine changes in the nature of the side chains strongly modulated the selectivity of the ACPPs with regard to hemolysis versus antimicrobial activity. The conformational preference of such compounds in various media was extensively studied, and the typical structure of cyclic α/aza‐β3‐pseudopeptides is described for the first time. Interestingly, such scaffolds are stabilized by successive inverse γ‐ and N‐N turns (hydrazino turns), a unique feature due to the aza‐β3 residues. The α‐amino acid side chains form a cluster on one face of the ring, while the aza‐β3‐amino acid side chains are projected around the ring in the equatorial orientation. Such structural data are particularly valuable to fine‐tune the bioactivity of these ACPPs by a structure‐based approach.
n‐Type Conjugated Polymer Based on Dicyanodistyrylbenzene and Naphthalene Diimide Units for All‐Polymer Solar Cells
Authors: He Baitian , Yin Qingwu , Zhang Jie , Jia Tao , Yang Xiye , Jiang Xiao‐Fang , Huang Fei , Cao Yong 
Published: February 2018

AbstractAll polymer solar cells (all‐PSCs), possessing superior mechanical strength and flexibility, offer the commercialization opportunity of the PSCs for flexible and portable devices. In this work, we designed and synthesized two copolymer acceptors based on dicyanodistyrylbenzene (DCB) and naphthalene diimide (NDI) units. The corresponding copolymer acceptors are denoted as PDCB‐NDI812 and PDCB‐NDI1014. The medium band gap copolymer PBDB‐T was selected as donor material for investigation of the photovoltaic performance. Two all‐PSCs devices showed power conversion efficiencies (PCE) of 4.26% and 3.43% for PDCB‐NDI812 and PDCB‐NDI1014, respectively. The improved PCE was ascribed to the higher short‐circuit current (JSC), greater charge carrier mobility and higher exciton dissociation probability of the PBDB‐T:PDCB‐NDI812 blend film. These results suggest that DCB unit and NDI unit based copolymer acceptors are promising candidates for high performance all‐PSCs.