bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid‐Phase Synthesis of DNA and RNA 5′‐O‐Triphosphates Using cycloSal Chemistry
Authors: Sarac Ivo , Meier Chris 
Published: March 2016

AbstractA chemical method for the synthesis of short strands of DNA and RNA 5′‐O‐triphosphates is described that makes use of the conventional coupling and oxidizing reagents that are readily available on standard DNA/RNA synthesizers. After automated solid‐phase synthesis of oligonucleotides and 5′‐O‐detritylation, a novel cycloSal‐phosphoramidite, 5‐chloro‐saligenyl‐N,N‐diisopropylphosphoramidite, was coupled to the 5′‐hydroxyl group and the product oxidized. The resulting support‐bonded 5′‐cycloSal‐oligonucleotide was reacted with pyrophosphate to yield 5′‐O‐triphosphorylated DNA/RNA oligonucleotides after cleavage from the support in high purity and excellent yields. The reaction sequence was adapted to be used completely on a standard automated oligonucleotide synthesizer. © 2016 by John Wiley & Sons, Inc.
Solid‐Phase Synthesis of Oligo‐ADP‐Ribose
Authors: Kistemaker Hans A.V. , Meeuwenoord Nico J. , Overkleeft Herman S. , van der Marel Gijsbert A. , Filippov Dmitri V. 
Published: March 2016

AbstractSolid‐phase methodology for synthesis of adenosine diphosphate ribose oligomers (ADPr‐oligomers) of defined length is described using an advanced 2‐ribosyl adenosine phosphoramidite building block that is prepared in solution via an expeditious and high‐yielding method. The methodology is based on phosphitylation of a phosphomonoester as the key condensation step in the solid‐phase protocol. As ADP‐ribosylation appears to be an important yet poorly understood post‐translational modification of proteins, the presented methodology for rapid synthesis of ADPr‐fragments of exactly defined length should be of interest for researchers in the field of structural biology and cell biology. © 2016 by John Wiley & Sons, Inc.
An Amphipathic trans‐Acting Phosphorothioate DNA Element Delivers Uncharged PNA and PMO Nucleic Acid Sequences in Mammalian Cells
Authors: Jain Harsh V. , Beaucage Serge L. 
Published: March 2016

AbstractAn innovative approach to the delivery of uncharged peptide nucleic acids (PNAs) and phosphorodiamidate morpholino (PMO) oligomers in mammalian cells is described and consists of extending the sequence of those oligomers with a short PNA‐polyA or PMO‐polyA tail. Recognition of the polyA‐tailed PNA or PMO oligomers by an amphipathic trans‐acting polythymidylic thiophosphate triester element (dTtaPS) results in efficient internalization of those oligomers in several cell lines. The authors’ findings indicate that cellular uptake of the oligomers occurs through an energy‐dependent mechanism and macropinocytosis appears to be the predominant endocytic pathway used for internalization. The functionality of the internalized oligomers is demonstrated by alternate splicing of the pre‐mRNA encoding luciferase in HeLa pLuc 705 cells. Amphipathic phosphorothioate DNA elements may represent a unique class of cellular transporters for robust delivery of uncharged nucleic acid sequences in live mammalian cells. © 2016 by John Wiley & Sons, Inc.
Synthesis of 5′‐Aldehyde Oligonucleotide
Authors: Lartia Rémy 
Published: March 2016

AbstractSynthesis of oligonucleotide ending with an aldehyde functional group at their 5′‐end (5′‐AON) is possible for both DNA (5′‐AODN) and RNA (5′‐AORN) series irrespectively of the nature of the last nucleobase. The 5′‐alcohol of on‐support ODN is mildly oxidized under Moffat conditions. Transient protection of the resulting aldehyde by N,N′‐diphenylethylenediamine derivatives allows cleavage, deprotection, and RP‐HPLC purification of the protected 5′‐AON. Finally, 5′‐AON is deprotected by usual acetic acid treatment. In the aggregates, 5′‐AON can be now synthesized and purified as routinely as non‐modified ODNs, following procedures similar to the well‐known “DMT‐On” strategy. © 2016 by John Wiley & Sons, Inc.
Revisiting the relationship between jet position, forced response, and annular mode variability in the southern midlatitudes
Authors: Simpson Isla R. , Polvani Lorenzo M. 
Published: March 2016

AbstractClimate models exhibit a wide range in latitudinal position of the Southern Hemisphere westerly jet. Previous work has demonstrated, in the annual mean, that models with lower latitude jets, exhibit greater poleward jet shifts under climate forcings. It has been argued that this behavior is due to stronger eddy/mean flow feedbacks in models with lower latitude jets, as inferred from the timescale of the Southern Annular Mode (SAM). Here we revisit this question with a focus on seasonality. Using a larger set of models and forcing scenarios from the Coupled Model Intercomparison Project, phase 5, we find that the jet position/jet shift relationship is strong in winter but insignificant in summer, whereas the model spread in SAM timescales arises primarily in summer, with winter timescales similar across models. The results, therefore, question previous interpretations and motivate an improved understanding of the spread in model behavior.
Cardiovascular Imaging in Mice
Authors: Phoon Colin K.L. , Turnbull Daniel H. 
Published: March 2016

AbstractThe mouse is the mammalian model of choice for investigating cardiovascular biology, given our ability to manipulate it by genetic, pharmacologic, mechanical, and environmental means. Imaging is an important approach to phenotyping both function and structure of cardiac and vascular components. This review details commonly used imaging approaches, with a focus on echocardiography and magnetic resonance imaging and brief overviews of other imaging modalities. We also briefly outline emerging imaging approaches but caution that reliability and validity data may be lacking. © 2016 by John Wiley & Sons, Inc.
Hydrohydrazination of Arylalkynes Catalyzed by an Expanded Ring N‐Heterocyclic Carbene (er‐NHC) Gold Complex Under Solvent‐Free Conditions
Authors: Morozov Oleg S. , Gribanov Pavel S. , Asachenko Andrey F. , Dorovatovskii Pavel V. , Khrustalev Victor N. , Rybakov Viktor B. , Nechaev Mikhail S. 
Published: March 2016

Abstract[(THD‐Dipp)AuOTf], supported by the strongly electron donating, sterically bulky THD‐Dipp (1,3‐bis(2,6‐diisopropylphenyl)hexahydro‐2H‐1,3‐diazepine‐2‐ylidene) seven‐membered N‐heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts‐ and Boc‐hydrazine to arylalkynes under solvent‐free conditions.magnified image
Technical Efficiency in Agribusiness: A Meta‐Analysis on Ghana
Authors: Djokoto Justice G. , Gidiglo Korbla F. 
Published: March 2016

ABSTRACTThe few meta‐analyses published on efficiency in agriculture focused on traditional agriculture to the neglect of agribusiness. This article presents a meta‐analysis on agribusiness using Ghana as a case. Databases including AgEconsearch, Google scholar, EBSCOHost, EmeraldInsight, and Wiley online Library among others were searched in order to identify published studies relating to the subsectors of agribusiness. The selected loglog fractional regression model revealed that mean technical efficiency (MTE) increased over time with a mean value of 62%. MTEs of geographical sections of Ghana are also similar. Time series models possess higher MTE than panel data MTEs. In line with theory, models without functional forms and distance functions elicited higher MTE than Cobb–Douglas and translog functions. Nontraditional agricultural production showed higher MTE than traditional agriculture. MTEs in the production subsector do not differ from those in the manufacturing subsector. While this indifference suggests that value adding manufacturing subsector is as efficient as the primary production agriculture, and the increasing MTE notwithstanding, efficiency improving measures including training in farm management are required to make up for the mean difference of 38% found. [JEL Classification: Q13].
Contractual Farming Arrangements, Quality Control, Incentives, and Distribution Failure in Kenya's Smallholder Horticulture: A Multivariate Probit Analysis
Authors: Kariuki Isaac Maina , Loy Jens‐Peter 
Published: March 2016

ABSTRACTWith the rapid growth of horticultural value chains, the use of contractual farming arrangements, strategies of quality control (farm audits/crop rejections), pricing incentives, and distribution efficiencies (crop collection arrangements) are increasingly breaking market barriers, for example, private standards, certification, traceability, and supply reliability in developing countries. Cognizant of market access, farm produce value, sustainable production, and reduction of postharvest losses, this paper investigated whether farm size, schooling, producer price, farm visits, and social capital networks condition these strategies. The results show that use of written contracts is conditioned by farm sizes, more extension, and number of producer groups (PGs) while farm certification is positively predicted by farm sizes, more extension, number of sellers in the village and seasons with the same buyer. However, certification is less responsive to producer prices. Crop rejections are predicted to be less depending on a farmer's education, number of PGs, and the producer price but are more likely to increase the more the number of sellers. Further, the results show that a forward pricing incentive is highly correlated with higher producer prices, more extension, and number of seasons with the same buyer. Finally, uncollected produce at harvest is likely to decrease with farm sizes, more education and extension, higher producer price, number of PGs, and seasons with the same buyer but is more likely to increase the higher the number of sellers. Implications are made. [EconLit citations: L14; Q13].
The International Wine Trade and Its New Export Dynamics (1988–2012): A Gravity Model Approach
Authors: Castillo J. Sebastián , Villanueva Emiliano C. , García‐Cortijo M. Carmen 
Published: March 2016

ABSTRACTAn acceleration of the wine industry globalization process has occurred in the last decades due to increased competition, the emergence of new producers and exporters, and the existence of new wine consuming countries. All this has led to global changes in production strategies and marketing. The aim of this paper is to analyze the changes that have occurred in the global wine export dynamics and define its determinants; to do so a gravity model was estimated in which (a) the main wine producers and consumers involved in international trade are present, (b) two distinctive scenarios are present: one of continuous change (1988–1999), and one of an established export dynamic (2002–2012), and (c) bulk and bottled wines are considered. The main results show that higher incomes, lower prices, cultural and geographical affinities, and trade agreements promote wine exports; the expansion of bottled wine trade, especially within the EU, is particularly highlighted. [EconLit citations: C40; F14; Q1].
Stapled Peptides with γ‐Methylated Hydrocarbon Chains for the Estrogen Receptor/Coactivator Interaction
Authors: Speltz Thomas E. , Fanning Sean W. , Mayne Christopher G. , Fowler Colin , Tajkhorshid Emad , Greene Geoffrey L. , Moore Terry W. 
Published: March 2016

Abstract“Stapled” peptides are typically designed to replace two non‐interacting residues with a constraining, olefinic staple. To mimic interacting leucine and isoleucine residues, we have created new amino acids that incorporate a methyl group in the γ‐position of the stapling amino acid S5. We have incorporated them into a sequence derived from steroid receptor coactivator 2, which interacts with estrogen receptor α. The best peptide (IC50=89 nm) replaces isoleucine 689 with an S‐γ‐methyl stapled amino acid, and has significantly higher affinity than unsubstituted peptides (390 and 760 nm). Through X‐ray crystallography and molecular dynamics studies, we show that the conformation taken up by the S‐γ‐methyl peptide minimizes the syn‐pentane interactions between the α‐ and γ‐methyl groups.
High‐Performance Lithium–Air Battery with a Coaxial‐Fiber Architecture
Authors: Zhang Ye , Wang Lie , Guo Ziyang , Xu Yifan , Wang Yonggang , Peng Huisheng 
Published: March 2016

AbstractThe lithium–air battery has been proposed as the next‐generation energy‐storage device with a much higher energy density compared with the conventional lithium‐ion battery. However, lithium–air batteries currently suffer enormous problems including parasitic reactions, low recyclability in air, degradation, and leakage of liquid electrolyte. Besides, they are designed into a rigid bulk structure that cannot meet the flexible requirement in the modern electronics. Herein, for the first time, a new family of fiber‐shaped lithium–air batteries with high electrochemical performances and flexibility has been developed. The battery exhibited a discharge capacity of 12 470 mAh g−1 and could stably work for 100 cycles in air; its electrochemical performances were well maintained under bending and after bending. It was also wearable and formed flexible power textiles for various electronic devices.
Controlled Core‐Modification of a Porphyrin into an Antiaromatic Isophlorin
Authors: Panchal Santosh P. , Gadekar Santosh C. , Anand Venkataramanarao G. 
Published: March 2016

AbstractPartial core‐modification of a porphyrin can be employed to synthesize the 20π antiaromatic isophlorin. Unlike the tetra‐, tri‐, and dipyrrole derivatives of a porphyrin, a monopyrrole porphyrin exhibits antiaromatic characteristics. It undergoes a two‐electron reversible ring oxidation to yield the 18π aromatic dication. 1H NMR analysis provides distinct evidence of the altered electronic characteristics through typical paratropic and diatropic ring current effects for the 4n and the (4n+2) π‐electron systems, respectively.
Synthesis of Monodisperse Bi‐Compartmentalized Amphiphilic Janus Microparticles for Tailored Assembly at the Oil–Water Interface
Authors: Kim Jeong Won , Cho Jangwoo , Cho Jaehong , Park Bum Jun , Kim Yong‐Jin , Choi Kyung‐Ho , Kim Jin Woong 
Published: March 2016

AbstractJanus particles endowed with controlled anisotropies represent promising building blocks and assembly materials because of their asymmetric functionalities. Herein, we show that using the seeded monomer swelling and polymerization technique allows us to obtain bi‐compartmentalized Janus microparticles that are generated depending on the phase miscibility of the poly (alkyl acrylate) chains against the polystyrene seed, thus minimizing the interfacial free energy. When tetradecyl acrylate is used, complete compartmentalization into two distinct bulbs can be achieved, while tuning the relative dimension ratio of compartmented bulb against the whole particle. Finally, we have demonstrated that selectively patching the silica nanoparticles onto one of the bulb surfaces gives amphiphilicity to the particles that can assemble at the oil–water interface with a designated level of adhesion, thus leading to development of a highly stable Pickering emulsion system.
Guided Self‐Propelled Leaping of Droplets on a Micro‐Anisotropic Superhydrophobic Surface
Authors: Liu Jie , Guo Haoyuan , Zhang Bo , Qiao Shasha , Shao Mingzhe , Zhang Xianren , Feng Xi‐Qiao , Li Qunyang , Song Yanlin , Jiang Lei , Wang Jianjun 
Published: March 2016

AbstractBy introducing anisotropic micropatterns on a superhydrophobic surface, we demonstrate that water microdroplets can coalesce and leap over the surface spontaneously along a prescribed direction. This controlled behavior is attributed to anisotropic liquid–solid adhesion. An analysis relating the preferential leaping probability to the geometrical parameters of the system is presented with consistent experimental results. Surfaces with this rare quality demonstrate many unique characteristics, such as self‐powered, and relatively long‐distance transport of microdroplets by “relay” coalescence‐induced leaping.
α‐Arylation of Ketimines with Aryl Sulfides at a Low Palladium Catalyst Loading
Authors: Gao Ke , Yorimitsu Hideki , Osuka Atsuhiro 
Published: March 2016

AbstractInstead of using aryl halides, aryl sulfides, typically poisonous to transition‐metal catalysts, were found to serve as aryl electrophiles in the catalytic α‐arylation of ketimines, a class of carbonyl derivatives. Low catalyst loadings (down to 0.5 mol %) of a palladium–NHC complex are sufficient for efficient arylation. α‐Arylated ketimine products are useful for the synthesis of various azaarenes, including 2,3‐diarylpyrroles, an indole, and pyrrolediones.
Stretchable Electrochemical Sensor for Real‐Time Monitoring of Cells and Tissues
Authors: Liu Yan‐Ling , Jin Zi‐He , Liu Yan‐Hong , Hu Xue‐Bo , Qin Yu , Xu Jia‐Quan , Fan Cui‐Fang , Huang Wei‐Hua 
Published: March 2016

AbstractStretchable electrochemical sensors are conceivably a powerful technique that provides important chemical information to unravel elastic and curvilinear living body. However, no breakthrough was made in stretchable electrochemical device for biological detection. Herein, we synthesized Au nanotubes (NTs) with large aspect ratio to construct an effective stretchable electrochemical sensor. Interlacing network of Au NTs endows the sensor with desirable stability against mechanical deformation, and Au nanostructure provides excellent electrochemical performance and biocompatibility. This allows for the first time, real‐time electrochemical monitoring of mechanically sensitive cells on the sensor both in their stretching‐free and stretching states as well as sensing of the inner lining of blood vessels. The results demonstrate the great potential of this sensor in electrochemical detection of living body, opening a new window for stretchable electrochemical sensor in biological exploration.
A Unified Treatment of the Relationship Between Ligand Substituents and Spin State in a Family of Iron(II) Complexes
Authors: Kershaw Cook Laurence J. , Kulmaczewski Rafal , Mohammed Rufeida , Dudley Stephen , Barrett Simon A. , Little Marc A. , Deeth Robert J. , Halcrow Malcolm A. 
Published: March 2016

AbstractThe influence of ligands on the spin state of a metal ion is of central importance for bioinorganic chemistry, and the production of base‐metal catalysts for synthesis applications. Complexes derived from [Fe(bpp)2]2+ (bpp=2,6‐di{pyrazol‐1‐yl}pyridine) can be high‐spin, low‐spin, or spin‐crossover (SCO) active depending on the ligand substituents. Plots of the SCO midpoint temperature (T
) in solution vs. the relevant Hammett parameter show that the low‐spin state of the complex is stabilized by electron‐withdrawing pyridyl (“X”) substituents, but also by electron‐donating pyrazolyl (“Y”) substituents. Moreover, when a subset of complexes with halogeno X or Y substituents is considered, the two sets of compounds instead show identical trends of a small reduction in T
for increasing substituent electronegativity. DFT calculations reproduce these disparate trends, which arise from competing influences of pyridyl and pyrazolyl ligand substituents on Fe‐L σ and π bonding.
Iridium(I)‐catalyzed C−H Borylation of α,β‐Unsaturated Esters with Bis(pinacolato)diboron
Authors: Sasaki Ikuo , Taguchi Jumpei , Doi Hana , Ito Hajime , Ishiyama Tatsuo 
Published: March 2016

AbstractA new process has been developed for the iridium(I)‐catalyzed vinylic C−H borylation of α,β‐unsaturated esters with bis(pinacolato)diboron (B2pin2). These reactions proceeded in octane at temperatures in the range of 80–120 °C to afford the corresponding alkenylboronic compounds in high yields with excellent regio‐ and stereoselectivities. The presence of an aryl ester led to significant improvements in the yields of the acyclic alkenylboronates. Crossover experiments involving deuterated substrates as well as a mixture of stereoisomers confirmed that this reaction proceeds via a 1,4‐addition/β‐hydride elimination mechanism. Notably, this reaction was also used to develop a one‐pot borylation/Suzuki–Miyaura cross‐coupling procedure.
Neutron star high‐mass binaries as the origin of SGR/AXP
Authors: Wang J. 
Published: March 2016

AbstractA close high‐mass binary system consisting of a neutron star (NS) and a massive OB supergiant companion is expected to lead to a Thorne‐Żytkow object (TZO) structure, which consists of a NS core and a stellar envelope. We use the scenario machine program to calculate the formation tracks of TZOs in close high‐mass NS binaries and their subsequent evolution. We propose and demonstrate that the explosion and instant contraction of a TZO structure leave its stellar remnant as a soft gamma‐ray repeater and an anomalous X‐ray pulsar respectively. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical spots on the surface of the strongly magnetic Herbig Ae star HD 101412
Authors: Järvinen S. P. , Hubrig S. , Schöller M. , Ilyin I. , Carroll T. A. , Korhonen H. 
Published: March 2016

AbstractDue to the knowledge of the rotation period and the presence of a rather strong surface magnetic field, the sharp‐lined young Herbig Ae star HD 101412 with a rotation period of 42 d has become one of the most well‐studied targets among the Herbig Ae stars. High‐resolution HARPS polarimetric spectra of HD 101412 were recently obtained on seven different epochs. Our study of the spectral variability over the part of the rotation cycle covered by HARPS observations reveals that the line profiles of the elements Mg, Si, Ca, Ti, Cr, Mn, Fe, and Sr are clearly variable while He exhibits variability that is opposite to the behaviour of the other elements studied. Since classical Ap stars usually show a relationship between the magnetic field geometry and the distribution of element spots, we used in our magnetic field measurements different line samples belonging to the three elements with the most numerous spectral lines, Ti, Cr, and Fe. Over the time interval covered by the available spectra, the longitudinal magnetic field changes sign from negative to positive polarity. The distribution of field values obtained using Ti, Cr, and Fe lines is, however, completely different compared to the magnetic field values determined in previous low‐resolution FORS 2 measurements, where hydrogen Balmer lines are the main contributors to the magnetic field measurements, indicating the presence of concentration of the studied iron‐peak elements in the region of the magnetic equator. Further, we discuss the potential role of contamination by the surrounding warm circumstellar matter in the appearance of Zeeman features obtained using Ti lines. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)