bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt(III)/Rhodium(III)‐Catalyzed Regio‐ and Stereoselective Allylation of 8‐Methylquinoline via sp3 C−H Activation
Authors: Li Na , Wang Yahui , Kong Lingheng , Chang Junbiao , Li Xingwei 
Published: May 2019

AbstractRegio‐ and stereoselective benzylic allylation of 8‐methylquinolines with (per)fluoroalkyl olefins has been realized via benzylic C−H activation and subsequent C−F cleavage. Both cobalt(III) and rhodium(III) catalysts can effect this transformation in good to high efficiency. The Rh(III)‐catalyzed system proceeded under moderate conditions with decent substrates scope, providing (Z)‐alkenyl fluorides with good to excellent regio‐ and stereoselectivity.magnified image
Ru‐Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
Authors: Pan Yixiao , Luo Zhenli , Xu Xin , Zhao Haoqiang , Han Jiahong , Xu Lijin , Fan Qinghua , Xiao Jianliang 
Published: May 2019

AbstractA ruthenium(II)‐catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2‐methylallyl)2(COD)], 1,1,1‐tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction‐sensitive. The choice of hydrogen source and acid co‐catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway.magnified image
Novel Selector‐Induced Current‐Limiting Effect through Asymmetry Control for High‐Density One‐Selector–One‐Resistor Crossbar Arrays
Authors: Kim Yumin , Kwon Young Jae , Kim Jihun , An Cheol Hyun , Park Taegyun , Kwon Dae Eun , Woo Hyo Cheon , Kim Hae Jin , Yoon Jung Ho , Hwang Cheol Seong 
Published: May 2019

AbstractCrossbar arrays that use resistance‐switching random‐access memory are passive arrays, requiring a high‐performance cell selector. However, the array‐writing margin is seriously limited by unwanted reset (switching from a low‐resistance state to a high‐resistance state) of the parallel connected cell to the selected cell at the moment of reset of the selected cell. This is also closely related to the presence of an interconnection‐wire resistance, which induces a switching‐voltage drop on the wire. Pt/TiO2/TiN selectors, with atomic‐layer‐deposited TiO2 films varying in thickness from 2 to 8 nm, are fabricated using a sputtered‐TiN bottom‐electrode layer. The selector with an 8‐nm‐thick TiO2 layer is found to be optimal, and is connected serially with an external cable to a Pt/2‐nm‐thick HfO2/TiN bipolar resistive‐switching memory cell. It shows good performance without breakdown and significant switching‐voltage increase without compliance current. HSPICE simulation shows that ≈0.5 Mb array size can be obtained by using a widely used tungsten electrode, demonstrating the feasibility of commercializing one‐selector–one‐resistor devices.
A consolidated flow regime map of upward gas fluidization
Authors: Sun Zeneng , Zhu Jesse 
Published: May 2019

AbstractA new flow regime map, resulting from more fundamental studies on the hydrodynamics and new flow regimes, is proposed in response to more practical reclassifications of the existing regimes with the development of upward gas‐solids fluidization systems. The previously reported flow regime maps and flow structures of some widely used fluidized beds are carefully examined. To better reflect the industrial applications, the fast fluidization regime is reclassified as high‐density and low‐density circulating fluidization regimes. A consolidated flow regime map is then proposed where the flow regimes of upward fluidization expand to include new types of fluidized beds such as circulating turbulent fluidized bed and high‐density circulating fluidized bed. The proposed flow regime map consists of six flow regimes: bubbling, turbulent, circulating turbulent, high‐density circulating and low‐density circulating fluidization, and pneumatic transport. The transitions between the regimes are discussed with new correlations proposed for fluid catalytic cracking type particles. Analysis on the dominating phase in the different types of fluidized beds reveals the dynamic changeover from solids phase continuous in conventional low‐velocity batch/“fixed” fluidization operations to gas phase continuous in high‐velocity continuous/“moving” fluidization operations and provides more insights to the transitions between the flow regimes for industrial design and practice.
Ecotypic divergences of the alpine herbPotentilla matsumuraeadapted to fellfield–snowbed habitats across a series of mountain sky islands
Authors: Hirao Akira S. , Shimono Yoshiko , Narita Kenji , Wada Naoya , Kudo Gaku 
Published: May 2019

PremiseDivergent selection due to environmental heterogeneity can lead to local adaptation. However, the ecological and evolutionary processes of local adaptation that occurs across multiple regions are often unknown. Our previous studies reported on the ecotypic divergence within a local area of variation ofPotentilla matsumurae, an alpine herb adapted to the fellfield–snowbed environment. Here we investigated large‐scale geographic patterns of ecotypic differentiation in this species to infer local adaptation and selective forces across multiple regions.MethodsWe compiled information on the overall distributions of fellfield and snowbed habitats on the mountains in Japan across the distribution of the species. Next, we conducted common garden experiments to test the adaptive divergence of the fellfield–snowbed plants derived from multiple regions. Finally, we evaluated phylogeographic structures based on cpDNAand allozyme variations and inferred the evolutionary history of ecotype differentiation.ResultsThe mosaic distribution of the fellfield–snowbed ecotypes across isolated mountaintops constitutes indirect evidence for habitat‐specific natural selection. The significant difference in survivorship between the ecotypes observed in a controlled snow environment provides more substantial evidence of local selection. Phylogeographic structures support the hypothesis that ecotypic divergence events from fellfield to snowbed populations occurred independently in at least two distinct regions.ConclusionsEcotypic divergence ofP. matsumuraehas occurred across a series of mountain sky islands. Local selection in snowy environments is a driving force that maintains the divergent ecotypes across multiple mountain regions and can contribute to the diversification of plants in heavy‐snow regions.
Next‐generation sequencing‐defined minimal residual disease before stem cell transplantation predicts acute myeloid leukemia relapse
Authors: Press Richard D. , Eickelberg Garrett , Froman Allison , Yang Fei , Stentz Alex , Flatley Ellen M. , Fan Guang , Lim Jeong Y. , Meyers Gabrielle , Maziarz Richard T. , Cook Rachel J. 
Published: May 2019

AbstractIn acute myeloid leukemia (AML), the assessment of post‐treatment minimal residual disease (MRD) may inform a more effective management approach. We investigated the prognostic utility of next‐generation sequencing (NGS)‐based MRD detection undertaken before hematopoietic stem cell transplantation (HSCT). Forty‐two AML subjects underwent serial disease monitoring both by standard methods, and a targeted 42‐gene NGS assay, able to detect leukemia‐specific mutant alleles (with >0.5% VAF) (mean 5.1 samples per subject). The prognostic relevance of any persisting diagnostic mutation before transplant (≤27 days) was assessed during 22.1 months (median) of post‐transplant follow‐up. The sensitivity of the NGS assay (27 MRD‐positive subjects) exceeded that of the non‐molecular methods (morphology, FISH, and flow cytometry) (11 positive subjects). Only one of the 13 subjects who relapsed after HSCT was NGS MRD‐negative (92% assay sensitivity). The cumulative incidence of post‐transplant leukemic relapse was significantly higher in the pre‐transplant NGS MRD‐positive (vs MRD‐negative) subjects (P = .014). After adjusting for TP53 mutation and transplant conditioning regimen, NGS MRD‐positivity retained independent prognostic significance for leukemic relapse (subdistribution hazard ratio = 7.3; P = .05). The pre‐transplant NGS MRD‐positive subjects also had significantly shortened progression‐free survival (P = .038), and marginally shortened overall survival (P = .068). In patients with AML undergoing HSCT, the pre‐transplant persistence of NGS‐defined MRD imparts a significant, sensitive, strong, and independent increased risk for subsequent leukemic relapse and death. Given that NGS can simultaneously detect multiple leukemia‐associated mutations, it can be used in the majority of AML patients to monitor disease burdens and inform treatment decisions.
Analysis of biogeographic ancestry reveals complex genetic histories for indigenous communities of St. Vincent and Trinidad
Authors: Benn Torres Jada , Martucci Victoria , Aldrich Melinda C. , Vilar Miguel G. , MacKinney Taryn , Tariq Muhammad , Gaieski Jill B. , Bharath Hernandez Ricardo , Browne Zoila E. , Stevenson Marlon , Walters Wendell , Schurr Theodore G. ,   The Genographic Consortium
Published: May 2019

AbstractObjectivesFrom a genetic perspective, relatively little is known about how mass emigrations of African, European, and Asian peoples beginning in the 16th century affected Indigenous Caribbean populations. Therefore, we explored the impact of serial colonization on the genetic variation of the first Caribbean islanders.Materials and methodsSixty‐four members of St. Vincent's Garifuna Community and 36 members of Trinidad's Santa Rosa First People's Community (FPC) of Arima were characterized for mitochondrial DNA and Y‐chromosome diversity via direct sequencing and targeted SNP and STR genotyping. A subset of 32 Garifuna and 18 FPC participants were genotyped using the GenoChip 2.0 microarray. The resulting data were used to examine genetic diversity, admixture, and sex biased gene flow in the study communities.ResultsThe Garifuna were most genetically comparable to African descendant populations, whereas the FPC were more similar to admixed American groups. Both communities also exhibited moderate frequencies of Indigenous American matrilines and patrilines. Autosomal SNP analysis indicated modest Indigenous American ancestry in these populations, while both showed varying degrees of African, European, South Asian, and East Asian ancestry, with patterns of sex‐biased gene flow differing between the island communities.DiscussionThese patterns of genetic variation are consistent with historical records of migration, forced, or voluntary, and suggest that different migration events shaped the genetic make‐up of each island community. This genomic study is the highest resolution analysis yet conducted with these communities, and provides a fuller understanding of the complex bio‐histories of Indigenous Caribbean peoples in the Lesser Antilles.
Genetic correlations in the dental dimensions ofSaguinus fuscicollis
Authors: Hardin Anna M. 
Published: May 2019

AbstractObjectivesThe objectives of this study are to describe genetic correlations between dental dimensions in a platyrrhine primate, to assess whether the brown‐mantled tamarin dentition exhibits genetic modularity by tooth type, and to discuss the relationship between body size reduction and the genetic architecture of dental traits.Materials and methodsGenetic correlations were estimated for linear dental measurements, estimated crown areas, and measures of relative premolar and molar size from 302 individuals, using a pedigree of 386 individuals, with maximum likelihood variance decomposition in SOLAR.ResultsGenetic correlation estimates indicate strong genetic integration in the dentition of brown‐mantled tamarins, with little evidence of modularity by tooth type, within and between the maxilla and mandible. The relative molar size variable hypothesized to be genetically patterned in baboons is not significantly heritable, and relative premolar size does not meet the criteria to be considered genetically patterned in this population.DiscussionThese results demonstrate variation in the pattern of genetic correlations between dental dimensions in primates, providing evidence of evolution of the genetic architecture in the callitrichine lineage. Genetic integration of dental dimensions without modularity by tooth type, as demonstrated here, is expected to constrain dental evolution in ways that modularity would not. The role of body size reduction in the callitrichine lineage in the evolution of the genetic architecture of the dentition is discussed. Quantitative genetic analyses of dental dimensions in more primate populations will provide greater evidence of variation and evolution in the genetic architecture underlying primate dental morphology.
Electroencephalographic reactivity as predictor of neurological outcome in postanoxic coma: A multicenter prospective cohort study
Authors: Admiraal Marjolein M. , van Rootselaar Anne‐Fleur , Hofmeijer Jeannette , Hoedemaekers Cornelia W. E. , van Kaam Christiaan R. , Keijzer Hanneke M. , van Putten Michel J. A. M. , Schultz Marcus J. , Horn Janneke 
Published: May 2019

ObjectiveOutcome prediction in patients after cardiac arrest (CA) is challenging. Electroencephalographic reactivity (EEG‐R) might be a reliable predictor. We aimed to determine the prognostic value of EEG‐R using a standardized assessment.MethodsIn a prospective cohort study, a strictly defined EEG‐R assessment protocol was executed twice per day in adult patients after CA. EEG‐R was classified as present or absent by 3 EEG readers, blinded to patient characteristics. Uncertain reactivity was classified as present. Primary outcome was best Cerebral Performance Category score (CPC) in 6 months after CA, dichotomized as good (CPC = 1–2) or poor (CPC = 3–5). EEG‐R was considered reliable for predicting poor outcome if specificity was ≥95%. For good outcome prediction, a specificity of ≥80% was used. Added value of EEG‐R was the increase in specificity when combined with EEG background, neurological examination, and somatosensory evoked potentials (SSEPs).ResultsOf 160 patients enrolled, 149 were available for analyses. Absence of EEG‐R for poor outcome prediction had a specificity of 82% and a sensitivity of 73%. For good outcome prediction, specificity was 73% and sensitivity 82%. Specificity for poor outcome prediction increased from 98% to 99% when EEG‐R was added to a multimodal model. For good outcome prediction, specificity increased from 70% to 89%.InterpretationEEG‐R testing in itself is not sufficiently reliable for outcome prediction in patients after CA. For poor outcome prediction, it has no substantial added value to EEG background, neurological examination, and SSEPs. For prediction of good outcome, EEG‐R seems to have added value. ANN NEUROL 2019
Formation of Neutral Peptide Aggregates as Studied by Mass‐Selective IR Action Spectroscopy
Authors: Bakels Sjors , Porskamp Sebastiaan B. A. , Rijs Anouk M. 
Published: May 2019

AbstractThe spontaneous aggregation of proteins and peptides is widely studied owing to its relation to neurodegenerative diseases. To understand the underlying principles of peptide aggregation, elucidation of structure and structural changes upon their formation is key. This level of detail can be obtained by studying the peptide self‐assembly in the gas phase. Structural characterization of aggregates is mainly done on charged species, as adding charges is an intrinsic part of the technique to bring molecules into the gas phase. Studying neutral peptide aggregates will complement the existing picture. These studies are restricted to dimers due to experimental limitations. Herein, we present advances in laser desorption molecular beam spectroscopy to form neutral peptide aggregates consisting of up to 14 monomeric peptides in the gas phase. The combination of this technique with IR–UV spectroscopy allowed us to select each aggregate by size and subsequently characterize its structure.
N‐heterocyclische Carbene katalysieren die radikalische Kupplung von Aldehyden mit redoxaktiven Estern
Authors: Song Runjiang , Chi Yonggui Robin 
Published: May 2019

AbstractDurch N‐heterocyclische Carbene katalysierte radikalische Reaktionen sind eine Herausforderung und wurden bislang wenig erforscht. In einer aktuellen Studie zeigten Ohmiya, Nagao et al., dass Carbonylkohlenstoffzentren von Aldehyden mit Alkylradikalen unter NHC‐Katalyse gekuppelt werden können. In eleganter Weise wird in dieser Studie ein redoxaktiver Carbonsäureester eingesetzt, der sich wie ein Ein‐Elektronen‐Oxidationsmittel verhält und das Breslow‐Intermediat in ein radikalisches Addukt umwandelt sowie gleichzeitig ein radikalisches Alkylintermediat als Reaktionspartner freisetzt.
Elektrolyte für wiederaufladbare Lithium‐Luft‐Batterien
Authors: Lai Jingning , Xing Yi , Chen Nan , Li Li , Wu Feng , Chen Renjie 
Published: May 2019

AbstractLithium (Li)‐Luft‐Batterien sind wegen ihrer enorm hohen Energiedichte vielversprechend für die elektrochemische Energiespeicherung. Es ist jedoch nach wie vor schwierig, praktische Li‐Luft‐Batterien zu erhalten, da sie eine starke Kapazitätsabnahme und eine geringe Entladungsrate aufweisen. Die verwendeten Elektrolyte stehen unter dem Verdacht, Zellversagen zu verursachen. In diesem Aufsatz liegt der Fokus auf den Chancen und Herausforderungen, die mit der Wahl des Elektrolyten für wiederaufladbare Li‐Luft‐Batterien einhergehen. Eine Zusammenfassung der Reaktionsmechanismen, internen Zusammensetzungen, Instabilitätsfaktoren, Auswahlkriterien und Design‐Ideen hinter den untersuchten Elektrolyten wird bereitgestellt, um Strategien zur Erfüllung der jeweiligen Batterieanforderungen entwickeln zu können. Insbesondere ionisch‐flüssige (IL‐)Elektrolyte und Festkörperelektrolyte bieten gute Möglichkeiten, sowohl die hohe Energiedichte als auch die Sicherheit zu kontrollieren.
Surface Reconstruction by a Coassembly Approach
Authors: Zhao Ya , Liu Li , Zhao Hanying 
Published: May 2019

AbstractMaterials with switchable surfaces, capable of changing surface properties under external stimuli, are playing a pivotal role in many applications, such as tissue engineering, biosensors, and drug/protein delivery. In this research silica particles with patterned and switchable surfaces are fabricated. Surface micelles on silica particles are formed by coassembly of polymer brushes and “free” block copolymer chains in a selective solvent. The cores of the surface micelles are crosslinked by anthracene photodimerization. After quaternization of the coronae, amphiphilic surface micelles are prepared. The surface micelles are able to rearrange in different media. After treatment with an organic solvent, the surfaces of silica particles are occupied by hydrophobic polymer components; in aqueous solution, the positively charged polymer chains are on the surfaces. The switching of the surface micelles results in changes in surface composition and wetting behaviors.
BN‐Embedded Tetrabenzopentacene: A Pentacene Derivative with Improved Stability
Authors: Zhuang Fang‐Dong , Sun Ze‐Hao , Yao Ze‐Fan , Chen Qi‐Ran , Huang Zhen , Yang Jing‐Hui , Wang Jie‐Yu , Pei Jian 
Published: May 2019

AbstractConsiderable efforts have been devoted to achieving stable acene derivatives for electronic applications; however, the instability is still a major issue for such derivatives. To achieve higher stability with minimum structural change, CC units in the acenes were replaced with isoelectronic BN units to produce a novel BN‐embedded tetrabenzopentacene (BNTBP). BNTBP, with a planar structure, is highly stable to air, moisture, light, and heat. Compared with its carbon analogue tetrabenzopentacene (TBP), BN embedment lowered the highest occupied molecular orbital (HOMO) energy level of BNTBP, changed the orbital distribution, and decreased the HOMO orbital coefficients at the central carbon atoms, which stabilize BNTBP molecules upon exposure to oxygen and sunlight. The single‐crystal microribbons of BNTBP exhibited good performance in field‐effect transistors (FETs). The high stability and good mobility of BNTBP indicates that BN incorporation is an effective approach to afford stable large‐sized acenes with desired properties.
Practical Catalytic Cleavage of C(sp3)−C(sp3) Bonds in Amines
Authors: Li Wu , Liu Weiping , Leonard David K. , Rabeah Jabor , Junge Kathrin , Brückner Angelika , Beller Matthias 
Published: May 2019

AbstractThe selective cleavage of thermodynamically stable C(sp3)−C(sp3) single bonds is rare compared to their ubiquitous formation. Herein, we describe a general methodology for such transformations using homogeneous copper‐based catalysts in the presence of air. The utility of this novel methodology is demonstrated for Cα−Cβ bond scission in >70 amines with excellent functional group tolerance. This transformation establishes tertiary amines as a general synthon for amides and provides valuable possibilities for their scalable functionalization in, for example, natural products and bioactive molecules.
Molecular Engineering‐Based Aptamer–Drug Conjugates with Accurate Tunability of Drug Ratios for Drug Combination Targeted Cancer Therapy
Authors: Zhou Fang , Wang Peng , Peng Yongbo , Zhang Pengge , Huang Qin , Sun Weidi , He Nongyue , Fu Ting , Zhao Zilong , Fang Xiaohong , Tan Weihong 
Published: May 2019

AbstractPolytherapy (or drug combination cancer therapy (DCCT)), targeting multiple mechanisms associated with tumor proliferation, can efficiently maximize therapeutic efficacy, decrease drug dosage, and reduce drug resistance. However, most DCCT strategies cannot coordinate the specific delivery of a drug combination in an accurately tuned ratio into cancer cells. To address these limitations, the present work reports the engineering of circular bivalent aptamer–drug conjugates (cb‐ApDCs). The cb‐ApDCs exhibit high stability, specific recognition, excellent cellular uptake, and esterase‐triggered release. Furthermore, the drug ratios in cb‐ApDCs can be tuned for an enhanced synergistic effect without the need for complex chemistry. Therefore, cb‐ApDCs provide a promising platform for the development of DCCT strategies for different drug combinations and ratios.
Palladium‐Catalyzed Directed meta‐Selective C−H Allylation of Arenes: Unactivated Internal Olefins as Allyl Surrogates
Authors: Achar Tapas Kumar , Zhang Xinglong , Mondal Rahul , Shanavas M. S. , Maiti Siddhartha , Maity Sabyasachi , Pal Nityananda , Paton Robert S. , Maiti Debabrata 
Published: May 2019

AbstractPalladium(II)‐catalyzed meta‐selective C−H allylation of arenes has been developed utilizing synthetically inert unactivated acyclic internal olefins as allylic surrogates. The strong σ‐donating and π‐accepting ability of pyrimidine‐based directing group facilitates the olefin insertion by overcoming inertness of the typical unactivated internal olefins. Exclusive allyl over styrenyl product selectivity as well as E stereoselectivity were achieved with broad substrate scope, wide functional‐group tolerance, and good to excellent yields. Late‐stage functionalisations of pharmaceuticals were demonstrated. Experimental and computational studies shed light on the mechanism and point to key steric control in the palladacycle, thus determining product selectivities.