bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of Amazonian deforestation on Amazon basin rainfall
Authors: Spracklen D. V. , Garcia‐Carreras L. 
Published: November 2015

AbstractWe completed a meta‐analysis of regional and global climate model simulations (n = 96) of the impact of Amazonian deforestation on Amazon basin rainfall. Across all simulations, mean (±1σ) change in annual mean Amazon basin rainfall was −12 ± 11%. Variability in simulated rainfall was not explained by differences in model resolution or surface parameters. Across all simulations we find a negative linear relationship between rainfall and deforestation extent, although individual studies often simulate a nonlinear response. Using the linear relationship, we estimate that deforestation in 2010 has reduced annual mean rainfall across the Amazon basin by 1.8 ± 0.3%, less than the interannual variability in observed rainfall. This may explain why a reduction in Amazon rainfall has not consistently been observed. We estimate that business‐as‐usual deforestation (based on deforestation rates prior to 2004) would lead to an 8.1 ± 1.4% reduction in annual mean Amazon basin rainfall by 2050, greater than natural variability.
Impact of the semidiurnal lunar tide on the midlatitude thermospheric wind and ionosphere during sudden stratosphere warmings
Authors: Pedatella N. M. , Maute A. 
Published: November 2015

AbstractVariability of the midlatitude ionosphere and thermosphere during the 2009 and 2013 sudden stratosphere warmings (SSWs) is investigated in the present study using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) observations and thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model (TIME‐GCM) simulations. Both the COSMIC observations and TIME‐GCM simulations reveal perturbations in the F region peak height (hmF2) at Southern Hemisphere midlatitudes during SSW time periods. The perturbations are ∼20–30 km, which corresponds to 10–20% variability of the background mean hmF2. The TIME‐GCM simulations and COSMIC observations of the hmF2 variability are in overall good agreement, and the simulations can thus be used to understand the physical processes responsible for the hmF2 variability. Through comparison of simulations with and without the migrating semidiurnal lunar tide (M2), we conclude that the midlatitude hmF2 variability is primarily driven by the propagation of the M2 into the thermosphere where it modulates the field‐aligned neutral winds, which in turn raise and lower the F region peak height. Though there are subtle differences, the consistency of the behavior between the 2009 and 2013 SSWs suggests that variability in the Southern Hemisphere midlatitude ionosphere and thermosphere is a consistent feature of the SSW impact on the upper atmosphere.
Topographic form stress in the Southern Ocean State Estimate
Authors: Masich Jessica , Chereskin Teresa K. , Mazloff Matthew R. 
Published: November 2015

AbstractWe diagnose the Southern Ocean momentum balance in a 6 year, eddy‐permitting state estimate of the Southern Ocean. We find that 95% of the zonal momentum input via wind stress at the surface is balanced by topographic form stress across ocean ridges, while the remaining 5% is balanced via bottom friction and momentum flux divergences at the northern and southern boundaries of the analysis domain. While the time‐mean zonal wind stress field exhibits a relatively uniform spatial distribution, time‐mean topographic form stress concentrates at shallow ridges and across the continents that lie within the Antarctic Circumpolar Current (ACC) latitudes; nearly 40% of topographic form stress occurs across South America, while the remaining 60% occurs across the major submerged ridges that underlie the ACC. Topographic form stress can be divided into shallow and deep regimes: the shallow regime contributes most of the westward form stress that serves as a momentum sink for the ACC system, while the deep regime consists of strong eastward and westward form stresses that largely cancel in the zonal integral. The time‐varying form stress signal, integrated longitudinally and over the ACC latitudes, tracks closely with the wind stress signal integrated over the same domain; at zero lag, 88% of the variance in the 6 year form stress time series can be explained by the wind stress signal, suggesting that changes in the integrated wind stress signal are communicated via rapid barotropic response down to the level of bottom topography.
Variability of monsoon intracloud and intercloud microphysics over the Indian subcontinent
Authors: Morwal S. B. , Brenguier J.‐L. , Padma Kumari B. , Maheskumar R. S. , Kulkarni J. R. 
Published: November 2015

AbstractIntracloud/intercloud variability of microphysical quantities during different monsoon conditions has been studied for the first time over India using in situ observations of cloud microphysics collected during the Cloud‐Aerosol Interaction and Precipitation Enhancement Experiment 2009. The observations for two inland locations (Hyderabad and Bareilly) for different phases of monsoon (preonset, onset, break, and active) have been used to investigate the entrainment and mixing processes which are defined with adiabatic fraction (ADFR) < 0.4 in monsoon clouds. The variation of factor k which is the ratio of cube of cloud droplet mean volume radius (rv) to cloud droplet effective radius (re), cloud droplet number concentration (N), liquid water content (LWC), and ADFR of LWC has been used to examine the intracloud and intercloud variability of cloud microphysical properties. During the preonset (Hyderabad), clouds were undiluted (<ADFR> ~ 0.59) with moderate concentration (<N> ~ 436 cm−3), an average re of 8 µm, and high value of factor k (0.774 ± 0.035). During break monsoon (Bareilly), clouds were diluted (<ADFR> ≤ 0.2) having numerous (<N> > 1000 cm−3) smaller droplets (re ≤ 6 µm) and a low value of factor k (0.678 ± 0.064). The clouds had similar characteristics (<ADFR> ~ 0.4 having lesser (<N> ~ 300 cm−3) droplets with re > 8 µm) over both stations during onset/active monsoon conditions. The investigation of the variability of intracloud and intercloud microphysics revealed positive correlation between factor k and N and no detectable correlation between factor k and N, respectively, and are sensitive to ADFR.
Global responses of gravity waves to planetary waves during stratospheric sudden warming observed by SABER
Authors: Cullens Chihoko Y. , England Scott L. , Immel Thomas J. 
Published: November 2015

AbstractThis study describes the global responses of observed gravity waves (GWs) to winter planetary wave (PW) variations during stratospheric sudden warmings (SSWs) using TIMED‐SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature measurements. Previous studies have shown responses of atmospheric temperature and parameterized GW drag to SSWs; however, the responses of global GW observations to SSWs have not been presented before. The responses are shown by calculating correlations between vertical components of Eliassen‐Palm (EP) fluxes in the winter polar stratosphere and global GW temperature amplitudes derived from SABER observations. Consistent with previous ground‐based and satellite observations, winter EP fluxes show positive correlations with GWs in the winter hemisphere. More interestingly, winter stratospheric EP fluxes are positively correlated with GWs in the tropics and in the summer mesosphere, indicating global variations of GWs in response to PW variations in the winter hemisphere. To study the mechanism of GW response to SSWs, global wind simulations from Specified Dynamics Whole Atmosphere Community Climate Model are used. Zonal wind anomalies (differences in the wind before and during SSWs) extend from the winter stratosphere to the summer mesosphere. By comparing anomalies in background winds to the observed patterns in the correlations between GWs and winter EP fluxes, we find that regions of positive correlation follow changes in background winds and zero‐wind lines. The results indicate that responses of SABER GWs in the summer hemisphere to winter PW variations during SSWs are likely caused by changes in GW propagation due to the changes in winds and atmospheric circulation.
Nucleophilic Difluoroalkylation of Isocyanates with Difluoromethyl 2‐Pyridyl Sulfone
Authors: Li Shan , Peng Peng , Wei Jun , Hu Yongzhou , Hu Jinbo , Sheng Rong 
Published: November 2015

AbstractThe nucleophilic difluoroalkylation of isocyanates with difluoromethyl 2‐pyridyl sulfone furnished 2,2‐difluoro‐2‐pyridinylsulfonylacetamides with good to excellent yield. These products can be converted to 2,2‐difluoroacetamide sulfinate, iododifluoroacetamide and 2‐aminopyridine derivatives easily.magnified image
Practical Access to Planar Chiral 1,2‐(α‐Ketotetramethylene)‐ ferrocene by Non‐Enzymatic Kinetic Resolution and Conclusive Confirmation of its Absolute Configuration
Authors: Liu Ruixia , Zhou Gang , Hall Thomas H. , Clarkson Guy J , Wills Martin , Chen Weiping 
Published: November 2015

AbstractThe asymmetric transfer hydrogenation (ATH) of racemic 1,2‐(α‐ketotetramethylene)ferrocene using the [N‐(tosyl)‐1,2‐diphenylethylendiamine]ruthenium(II) complex [TsDPEN‐Ru(II)] as catalyst takes place with a high level of kinetic resolution to deliver the ketone in up to 99% ee. The X‐ray crystallographic structure of a derivative of the alcohol co‐product serves to confirm conclusively both the absolute configuration of 1,2‐(α‐ketotetramethylene)ferrocene and the endo‐reduction selectivity.magnified image
Graft copolymers of microcrystalline cellulose as reinforcing agent for elastomers based on natural rubber
Authors: Deng Fei , Zhang Yinhang , Ge Xin , Li MeiChun , Li Xiangxu , Cho Ur Ryong 
Published: November 2015

ABSTRACTIn the present study, free radical graft copolymerization of acrylic monomers and microcrystalline cellulose (MCC) was applied to develop a biopolymer for natural rubber reinforcements. The copolymerization was carried out in aqueous media. Cerium ammonium nitrate was employed as the initiator in the presence of nitric acid. Acrylic monomers used in the copolymer synthesis were ethyl acrylate (EA) and butyl acrylate (BA). Effects of monomer concentration, initiator concentration, polymerization time, and polymerization temperature on the obtained graft copolymers were investigated. The graft parameters were obtained by thermal gravimetric analysis method. The obtained copolymers (MCC‐g‐PEA, MCC‐g‐PBA) were characterized by attenuated total reflection, wide‐angle X‐ray diffraction, field‐emission electron microscopy, and thermal gravimetric analysis. In comparison to native MCC, better thermal stability of graft copolymers were observed. In addition, the graft copolymers reinforced natural rubber composites were produced, and sulfur was used as the vulcanizing agent. Their vulcanization and mechanical properties were characterized. Comparing to the native MCC reinforced natural rubber composites, the copolymers reinforced natural rubber composites shows improved mechanical properties, indicating the copolymer's potential application as rubber reinforcements. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43087.
Preparation and characterization of nanocomposite materials based on polyamide‐6 and modified ordered mesoporous silica KIT‐6
Authors: Dinari Mohammad , Mohammadnezhad Gholamhossein , Nabiyan Afshin 
Published: November 2015

ABSTRACTOrdered mesoporous silica has been drawn great interest in many areas of modern science and technology. In this study, mesoporous silica KIT‐6 was modified with 3‐mercaptopropyl‐trimethoxysilane by sono‐chemical method and reflux. Low‐angle powder X‐ray diffraction (XRD) and transmission electron microscopy (TEM) images confirmed the presence well‐ordered arrangement of large pores and a relatively ordered mesostructure for the functionalized materials. The nanocomposites of polyamide‐6 and modified‐KIT (3 and 6 wt %) were prepared under reflux and followed by sonication for 2h. The prepared hybrid nanocomposites were characterized by Fourier transform‐infrared spectroscopy, XRD, field emission‐scanning electron microscopy and TEM techniques. Thermogravimetric analysis data showed that the onset of decomposition temperature of the nanocomposites was higher than that of pristine polyamide‐6, shifting toward higher temperatures as the amount of modified‐KIT was increased. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43098.
Keto‐benzo[h]‐Coumarin‐Based Near‐Infrared Dyes with Large Stokes Shifts for Bioimaging Applications
Authors: Niu Guangle , Liu Weimin , Xiao Hongyan , Zhang Hongyan , Chen Jianhong , Dai Qing , Ge Jiechao , Wu Jiasheng , Wang Pengfei 
Published: November 2015

AbstractFluorescence imaging is a promising tool for the visualization of biomolecules in living systems and there is great demand for new fluorescent dyes that absorb and emit in the near‐infrared (NIR) region. Herein, we constructed three new fluorescent dyes (NBC dyes) based on keto‐benzo[h]coumarin (k‐BC) and benzopyrilium salts. These dyes showed large Stokes shifts (>100 nm) and NIR emission (>800 nm). The relationship between the structures and optical properties of these dyes was further investigated by using density functional theory calculations at the B3LYP/6‐3G level of theory. Fluorescence images indicated that the fabricated dyes exhibited good photostability and low cytotoxicity and, thus, have potential applications as imaging agents in living cells and animals.
Introducing chemical biology applications to introductory organic chemistry students using series of weekly assignments
Authors: Kanin Maralee R. , Pontrello Jason K. 
Published: November 2015

AbstractCalls to bring interdisciplinary content and examples into introductory science courses have increased, yet strategies that involve course restructuring often suffer from the need for a significant faculty commitment to motivate change. Minimizing the need for dramatic course reorganization, the structure, reactivity, and chemical biology applications of classes of biological monomers and polymers have been integrated into introductory organic chemistry courses through three series of semester‐long weekly assignments that explored (a) Carbohydrates and Oligosaccharides, (b) Amino Acids, Peptides, and Proteins, and (c) Nucleosides, Nucleotides, and Nucleic Acids. Comparisons of unannounced pre‐ and post tests revealed improved understanding of a reaction introduced in the assignments, and course examinations evaluated cumulative assignment topics. Course surveys revealed that demonstrating biologically relevant applications consistently throughout the semesters enhanced student interest in the connection between basic organic chemistry content and its application to new and unfamiliar bio‐related examples. Covering basic material related to these classes of molecules outside of the classroom opened lecture time to allow the instructor to further build on information developed through the weekly assignments, teaching advanced topics and applications typically not covered in an introductory organic chemistry lecture course. Assignments were implemented as homework, either with or without accompanying discussion, in both laboratory and lecture organic courses within the context of the existing course structures. © 2015 by The International Union of Biochemistry and Molecular Biology, 44:168–178, 2016.
Chemoproteomic Approach to Explore the Target Profile of GPCR ligands: Application to 5‐HT1A and 5‐HT6 Receptors
Authors: Gamo Ana M. , González‐Vera Juan A. , Rueda‐Zubiaurre Ainoa , Alonso Dulce , Vázquez‐Villa Henar , Martín‐Couce Lidia , Palomares Óscar , López Juan A. , Martín‐Fontecha Mar , Benhamú Bellinda , López‐Rodríguez María L. , Ortega‐Gutiérrez Silvia 
Published: November 2015

AbstractDetermination of the targets of a compound remains an essential aspect in drug discovery. A complete understanding of all binding interactions is critical to recognize in advance both therapeutic effects and undesired consequences. However, the complete polypharmacology of many drugs currently in clinical development is still unknown, especially in the case of G protein‐coupled receptor (GPCR) ligands. In this work we have developed a chemoproteomic platform based on the use of chemical probes to explore the target profile of a compound in biological systems. As proof of concept, this methodology has been applied to selected ligands of the therapeutically relevant serotonin 5‐HT1A and 5‐HT6 receptors, and we have identified and validated some of their off‐targets. This approach could be extended to other drugs of interest to study the targeted proteome in disease‐relevant systems.
DNA Triplexes That Bind Several Cofactor Molecules
Authors: Vollmer Sven , Richert Clemens 
Published: November 2015

AbstractCofactors are critical for energy‐consuming processes in the cell. Harnessing such processes for practical applications requires control over the concentration of cofactors. We have recently shown that DNA triplex motifs with a designed binding site can be used to capture and release nucleotides with low micromolar dissociation constants. In order to increase the storage capacity of such triplex motifs, we have explored the limits of ligand binding through designed cavities in the oligopurine tract. Oligonucleotides with up to six non‐nucleotide bridges between purines were synthesized and their ability to bind ATP, cAMP or FAD was measured. Triplex motifs with several single‐nucleotide binding sites were found to bind purines more tightly than triplexes with one large binding site. The optimized triplex consists of 59 residues and four C3‐bridges. It can bind up to four equivalents of ligand with apparent Kd values of 52 µM for ATP, 9 µM for FAD, and 2 µM for cAMP. An immobilized version fuels bioluminescence via release of ATP at body temperature. These results show that motifs for high‐density capture, storage and release of energy‐rich biomolecules can be constructed from synthetic DNA.
Highly Selective Addition of a Broad Spectrum of Trimethylsilane Pro‐nucleophiles to N‐tert‐Butanesulfinyl Imines
Authors: Das Manas , O'Shea Donal F. 
Published: November 2015

AbstractAddition of organotrimethylsilane reagents to chiral N‐tert‐butanesulfinyl imines can be achieved in good yields and with excellent diastereoselectivities by employing TMSO−/Bu4N+ as a Lewis base activator in THF. A variety of aliphatic, aromatic, heteroaromatic and organometallic chiral imines were utilised as electrophiles for the synthesis of enantioenriched N‐tert‐butanesulfinyl amides. Remarkably, the same sets of reaction conditions could be used with a highly diverse range of bench‐stable organotrimethylsilane reagents, which highlights the generality and robustness of this methodology.
Mussel‐Inspired Materials: Self‐Healing through Coordination Chemistry
Authors: Krogsgaard Marie , Nue Vicki , Birkedal Henrik 
Published: November 2015

AbstractImproved understanding of the underwater attachment strategy of the blue mussels and other marine organisms has inspired researchers to find new routes to advanced materials. Mussels use polyphenols, such as the catechol‐containing amino acid 3,4‐dihydroxyphenylalanine (DOPA), to attach to surfaces. Catechols and their analogues can undergo both oxidative covalent cross‐linking under alkaline conditions and take part in coordination chemistry. The former has resulted in the widespread use of polydopamine and related materials. The latter is emerging as a tool to make self‐healing materials due to the reversible nature of coordination bonds. We review how mussel‐inspired materials have been made with a focus on the less developed use of metal coordination and illustrate how this chemistry can be widely to make self‐healing materials.
Confined Polymerization in Highly Ordered Mesoporous Organosilicas
Authors: Comotti Angiolina , Bracco Silvia , Beretta Mario , Perego Jacopo , Gemmi Mauro , Sozzani Piero 
Published: November 2015

AbstractHybrid mesoporous organosilica exhibiting crystal‐like order in the walls provided an ideal channel reaction vessel for the confined polymerization of acrylonitrile (PAN). The resulting high‐molecular‐mass PAN fills the channels at high yield and forms an ordered nanostructure of polymer nanobundles enclosed into the hybrid matrix. The in situ thermal transformation of PAN into rigid polyconjugated and, eventually, into condensed polyaromatic carbon nanofibers, retains the periodic architecture. Simultaneously, the matrix evolves showing the fusion of the p‐phenylene rings and the cleavage of carbonsilicon bonds: this gives rise to graphitic‐carbon/silica nanocomposites containing hyper‐oxydrylated silica nanophases. Interestingly, the 3D hexagonal mesostructure survives in the carbonaceous material. The exploitation of porous materials of high capacity and a hybrid nature, for polymerization in the confined state, followed by high temperature treatments, allowed us to achieve unique and precisely fabricated nanostructures, thus paving the way for the construction of fine‐tuned electronic and light‐harvesting materials.
Influence of Solvent‐Like Sidechains on the Adsorption of Light Hydrocarbons in Metal–Organic Frameworks
Authors: Schneemann Andreas , Bloch Eric D. , Henke Sebastian , Llewellyn Philip L. , Long Jeffrey R. , Fischer Roland A. 
Published: November 2015

AbstractA variety of strategies have been developed to adsorb and separate light hydrocarbons in metal–organic frameworks. Here, we present a new approach in which the pores of a framework are lined with four different C3 sidechains that feature various degrees of branching and saturation. These pendant groups, which essentially mimic a low‐density solvent with restricted degrees of freedom, offer tunable control of dispersive host–guest interactions. The performance of a series of frameworks of the type Zn2(fu‐bdc)2(dabco) (fu‐bdc2−=functionalized 1,4‐benzenedicarboxylate; dabco=1,4‐diazabicyclo[2.2.2]octane), which feature a pillared layer structure, were investigated for the adsorption and separation of methane, ethane, ethylene, and acetylene. The four frameworks exhibit low methane uptake, whereas C2 hydrocarbon uptake is substantially higher as a result of the enhanced interaction of these molecules with the ligand sidechains. Most significantly, the adsorption quantities and selectivity were found to depend strongly upon the type of sidechains attached to the framework scaffold.
Genotyping confirms inheritance of the rare At(a−) type in a case of haemolytic disease of the newborn
Authors: McBean Rhiannon , Liew Yew‐Wah , Wilson Brett , Kupatawintu Pawinee , Emthip Morakot , Hyland Catherine , Flower Robert 
Published: November 2015

AbstractThe Ata blood group antigen (now AUG2 in the Augustine system) is a high‐frequency antigen with negative phenotype At(a−) found only in individuals of African ancestry. In a twin pregnancy, the fifth pregnancy in a woman of African origin, serological investigations confirmed that the mother was At(a−) and anti‐Ata was detected. DNA samples were exome sequenced and alignment was performed to allow variant calling. It was confirmed that the single nucleotide polymorphism, rs45458701, within the SLC29A1 gene encoding the ENT1 protein, recently reported to be a basis of the At(a−) phenotype was also the basis of the phenotype in this family. The reagents for serological analysis required to identify the rare blood type present in this mother are held in only a few reference laboratories worldwide. This case highlights the utility of genetic methods in resolving complex investigations involving blood grouping and demonstrates that genotyping of variants associated with blood types present in specific ethnic groups may be the fastest method available for identification of the basis of fetomaternal incompatibilities.