bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Reductions Without External Hydrogen Gas: Broad Scope Hydrogenations with Tetrahydroxydiboron and a Tertiary Amine
Authors: Korvinson Kirill A. , Akula Hari K. , Malinchak Casina T. , Sebastian Dellamol , Wei Wei , Khandaker Tashrique A. , Andrzejewska Magdalena R. , Zajc Barbara , Lakshman Mahesh K. 
Published: November 2019

AbstractFacile reduction of aryl halides with a combination of 5% Pd/C, B2(OH)4, and 4‐methylmorpholine is reported. Aryl bromides, iodides, and chlorides were efficiently reduced. Aryl dihalides containing two different halogen atoms underwent selective reduction: I over Br and Cl, and Br over Cl. Beyond these, aryl triflates were efficiently reduced. This combination was broadly general, effectuating reductions of benzylic halides and ethers, alkenes, alkynes, aldehydes, and azides, as well as for N‐Cbz deprotection. A cyano group was unaffected, but a nitro group and a ketone underwent reduction to a low extent. When B2(OD)4 was used for aryl halide reduction, a significant amount of deuteriation occurred. However, H atom incorporation competed and increased in slower reactions. 4‐Methylmorpholine was identified as a possible source of H atoms in this, but a combination of only 4‐methylmorpholine and Pd/C did not result in reduction. Hydrogen gas has been observed to form with this reagent combination. Experiments aimed at understanding the chemistry led to the proposal of a plausible mechanism and to the identification of N,N‐bis(methyl‐d3)pyridin‐4‐amine (DMAP‐d6) and B2(OD)4 as an effective combination for full aromatic deuteriation.magnified image
An Ultra‐Flexible Solution‐Processed Metal‐Oxide/Carbon Nanotube Complementary Circuit Amplifier with Highly Reliable Electrical and Mechanical Stability
Authors: Kim Kyung‐Tae , Kang Seung‐Han , Kim Jaeyoung , Heo Jae Sang , Kim Yong‐Hoon , Park Sung Kyu 
Published: November 2019

AbstractHere, high‐performance flexible complementary metal‐oxide–semiconductor (CMOS) amplifiers with extremely stable electro‐mechanical characteristics by employing low‐temperature solution‐processed amorphous indium–gallium–zinc oxide (a‐IGZO) and single‐walled carbon nanotube (SWCNT) thin film transistors (TFTs) is demonstrated. The photochemical‐activated combustion sol–gel a‐IGZO and SWCNT TFTs show average saturation mobility of 6.82 and 0.51 cm2 V−1 s−1, respectively. Based on the devices, a‐IGZO/SWCNT‐based CMOS amplifiers are implemented on ultrathin and flexible substrates (thickness of ≈3 µm), exhibiting small‐signal gain and unity‐gain bandwidth of up to 25 dB and 25 kHz, respectively, with highly reliable characteristics from 1000 bending stress (radius of 125 µm) and positive gate bias stress conditions (for up to 3 h). The underlying mechanisms of the CMOS performance combined with large output impedance of the SWCNT load are investigated in detail via various circuit implementations and automatic integrated circuit modeling Spice simulation and comprehensive electrical analysis. To ensure the viability of the extremely stable electromechanical properties of the flexible amplifier, a numerical analysis is carried out based on finite‐element methods with an integrated circuit emphasis to find the best match of the CMOS architecture and optimized structural integrity, verifying highly reliable and scalable skin‐like electronics.
Nonpolar Resistive Switching of Multilayer‐hBN‐Based Memories
Authors: Zhuang Pingping , Lin Weiyi , Ahn Jaehyun , Catalano Massimo , Chou Harry , Roy Anupam , Quevedo‐Lopez Manuel , Colombo Luigi , Cai Weiwei , Banerjee Sanjay K. 
Published: November 2019

AbstractResistive switching (RS) induced by electrical bias is observed in numerous materials, including 2D hexagonal boron nitride (hBN), which has been used in resistive random access memories (RRAMs) in recent years. For practical high‐density, cross‐point memory arrays, compared with bipolar memories, nonpolar (or unipolar) devices are preferable in terms of peripheral circuit design and storage density. The non‐volatile nonpolar RS phenomenon of hBN‐based RRAMs with Ti/hBN/Au structure as a prototype is reported. Stable manual DC switching for ≈103cycles with an average window over five orders of magnitude is demonstrated. After identifying a possible mechanism related to the Joule heat that contributes to the rupture of conductive filaments in nonpolar RS operations, this mechanism is validated by analyzing the occurrence of the “Re‐set” process. Though the intriguing physical origin still requires more comprehensive studies, the achievement of nonpolar RS should make it more feasible to use hBN in practical RRAM technology.
A Modified Delphi Study to Prioritize Content for a Simulation‐based Pediatric Curriculum for Emergency Medicine Residency Training Programs
Authors: Mitzman Jennifer , Bank Ilana , Burns Rebekah A. , Nguyen Michael C. , Zaveri Pavan , Falk Michael J. , Madhok Manu , Dietrich Ann , Wall Jessica , Waseem Muhammad , Wu Teresa , McQueen Alisa , Peng Cynthia R. , Phillips Brian , Bullaro Francesca M. , Chang Cindy D. , Shahid Sam , Way David P. , Auerbach Marc 
Published: November 2019

AbstractObjectivesPediatric training is an essential component of emergency medicine (EM) residency. The heterogeneity of pediatric experiences poses a significant challenge to training programs. A national simulation curriculum can assist in providing a standardized foundation of pediatric training experience to all EM trainees. Previously, a consensus‐derived set of content for a pediatric curriculum for EM was published. This study aimed to prioritize that content to establish a pediatric simulation‐based curriculum for all EM residency programs.MethodsSeventy‐three participants were recruited to participate in a three‐round modified Delphi project from 10 stakeholder organizations. In round 1, participants ranked 275 content items from a published set of pediatric curricular items for EM residents into one of four categories: definitely must, probably should, possibly could, or should not be taught using simulation in all residency programs. Additionally, in round 1 participants were asked to contribute additional items. These items were then added to the survey in round 2. In round 2, participants were provided the ratings of the entire panel and asked to rerank the items. Round 3 involved participants dichotomously rating the items.ResultsA total of 73 participants participated and 98% completed all three rounds. Round 1 resulted in 61 items rated as definitely must, 72 as probably should, 56 as possibly could, 17 as should not, and 99 new items were suggested. Round 2 resulted in 52 items rated as definitely must, 91 as probably should, 120 as possibly could, and 42 as should not. Round 3 resulted in 56 items rated as definitely must be taught using simulation in all programs.ConclusionsThe completed modified Delphi process developed a consensus on 56 pediatric items that definitely must be taught using simulation in all EM residency programs (20 resuscitation, nine nonresuscitation, and 26 skills). These data will serve as a targeted needs assessment to inform the development of a standard pediatric simulation curriculum for all EM residency programs.
Parallel increases in insect herbivory and defenses with increasing elevation for both saplings and adult trees of oak (Quercus) species
Authors: Galmán Andrea , Abdala‐Roberts Luis , Covelo Felisa , Rasmann Sergio , Moreira Xoaquín 
Published: November 2019

PremiseHerbivory is predicted to increase toward warmer and more stable climates found at lower elevations, and this increase should select for higher plant defenses. Still, a number of recent studies have reported either no evidence of such gradients or reverse patterns. One source of inconsistency may be that plant ontogenetic variation is usually not accounted for and may influence levels of plant defenses and herbivory.MethodsWe tested for elevational gradients in insect leaf herbivory and leaf traits putatively associated with herbivore resistance across eight oak (Quercus, Fagaceae) species and compared these patterns for saplings and adult trees. To this end, we surveyed insect leaf herbivory and leaf traits (phenolic compounds, toughness and nutrients) in naturally occurring populations of each oak species at low‐, mid‐ or high‐elevation sites throughout the Iberian Peninsula.ResultsLeaf herbivory and chemical defenses (lignins) were unexpectedly higher at mid‐ and high‐elevation sites than at low‐elevation sites. In addition, leaf chemical defenses (lignins and condensed tannins) were higher for saplings than adult trees, whereas herbivory did not significantly differ between ontogenetic stages. Overall, elevational variation in herbivory and plant chemical defenses were consistent across ontogenetic stages (i.e., elevational gradients were not contingent upon tree ontogeny), and herbivory and leaf traits were not associated across elevations.ConclusionsThese findings suggest disassociated patterns of elevational variation in herbivory and leaf traits, which, in turn, are independent of plant ontogenetic stage.
PRC2‐complex related dysfunction in overgrowth syndromes: A review of EZH2, EED, and SUZ12 and their syndromic phenotypes
Authors: Cyrus Sharri , Burkardt Deepika , Weaver David D. , Gibson William T. 
Published: November 2019

AbstractThe EZH2, EED, and SUZ12 genes encode proteins that comprise core components of the polycomb repressive complex 2 (PRC2), an epigenetic “writer” with H3K27 methyltransferase activity, catalyzing the addition of up to three methyl groups on histone 3 at lysine residue 27 (H3K27). Partial loss‐of‐function variants in genes encoding the EZH2 and EED subunits of the complex lead to overgrowth, macrocephaly, advanced bone age, variable intellectual disability, and distinctive facial features. EZH2‐associated overgrowth, caused by constitutional heterozygous mutations within Enhancer of Zeste homologue 2 (EZH2), has a phenotypic spectrum ranging from tall stature without obvious intellectual disability or dysmorphic features to classical Weaver syndrome (OMIM #277590). EED‐associated overgrowth (Cohen–Gibson syndrome; OMIM #617561) is caused by germline heterozygous mutations in Embryonic Ectoderm Development (EED), and manifests overgrowth and intellectual disability (OGID), along with other features similar to Weaver syndrome. Most recently, rare coding variants in SUZ12 have also been described that present with clinical characteristics similar to the previous two syndromes. Here we review the PRC2 complex and clinical syndromes of OGID associated with core components EZH2, EED, and SUZ12.
Early Intrathecal T Helper 17.1 Cell Activity in Huntington Disease
Authors: von Essen Marina R. , Hellem Marie N. N. , Vinther‐Jensen Tua , Ammitzbøll Cecilie , Hansen Rikke H. , Hjermind Lena E. , Nielsen Troels T. , Nielsen Jørgen E. , Sellebjerg Finn 
Published: November 2019

ObjectiveHuntington disease (HD) is an autosomal dominantly inherited neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin (HTT) gene. No disease‐modifying therapy exists for the treatment of patients with HD. The purpose of this study was therefore to investigate early disease mechanisms that potentially could be used as a target therapeutically.MethodsLymphocyte activity in cerebrospinal fluid (CSF) from 4 cohorts of HTT gene expansion carriers (n = 121 in total) and controls was analyzed by techniques based on flow cytometry and enzyme‐linked immunosorbent assays.ResultsThe data of this study provide evidence of immune abnormalities before motor onset of disease. In CSF of HTT gene expansion carriers, we found increased levels of proinflammatory cytokines, including IL‐17, and increased consumption of the lymphocyte growth factor IL‐7 before motor onset of HD. In concordance, we observed an increased prevalence of IL‐17–producing Th17.1 cells in the CSF of HTT gene expansion carriers, predominantly in pre–motor manifest individuals. The frequency of intrathecal Th17.1 cells correlated negatively with progression of HD and the level of neurodegeneration, suggesting a role of Th17.1 cells in the early disease stage. We also observed a skewing in the balance between proinflammatory and regulatory T cells potentially favoring a proinflammatory intrathecal environment in HTT gene expansion carriers.InterpretationThese data suggest that Th17.1 cells are implicated in the earliest pathogenic phases of HD and suggest that treatment to dampen T ‐cell–driven inflammation before motor onset might be of benefit in HTT gene expansion carriers. ANN NEUROL 2020;87:246–255
Zinc‐Catalyzed Asymmetric Formal [4+3] Annulation of Isoxazoles with Enynol Ethers by 6π Electrocyclization: Stereoselective Access to 2H‐Azepines
Authors: Zhu Xin‐Qi , Wang Ze‐Shu , Hou Bo‐Shang , Zhang Hao‐Wen , Deng Chao , Ye Long‐Wu 
Published: November 2019

Abstract6π electrocyclization has attracted interest in organic synthesis because of its high stereospecificity and atom economy in the construction of versatile 5–7‐membered cycles. However, examples of asymmetric 6π electrocyclization are quite scarce, and have to rely on the use of chiral organocatalysts, and been limited to pentadienyl‐anion‐ and triene‐type 6π electrocyclizations. Described herein is a zinc‐catalyzed formal [4+3] annulation of isoxazoles with 3‐en‐1‐ynol ethers via 6π electrocyclization, leading to the site‐selective synthesis of functionalized 2H‐azepines and 4H‐azepines in good to excellent yields with broad substrate scope. Moreover, this strategy has also been used to produce chiral 2H‐azepines with high enantioselectivities (up to 97:3 e.r.). This protocol not only is the first asymmetric heptatrienyl‐cation‐type 6π electrocyclization, but also is the first asymmetric reaction of isoxazoles with alkynes and the first asymmetric catalysis based on ynol ethers.
The 3F Library: Fluorinated Fsp3‐Rich Fragments for Expeditious 19F NMR Based Screening
Authors: Troelsen Nikolaj S. , Shanina Elena , Gonzalez‐Romero Diego , Danková Daniela , Jensen Ida S. A. , Śniady Katarzyna J. , Nami Faranak , Zhang Hengxi , Rademacher Christoph , Cuenda Ana , Gotfredsen Charlotte H. , Clausen Mads H. 
Published: November 2019

AbstractFragment‐based drug discovery (FBDD) is a popular method in academia and the pharmaceutical industry for the discovery of early lead candidates. Despite its wide‐spread use, the approach still suffers from laborious screening workflows and a limited diversity in the fragments applied. Presented here is the design, synthesis, and biological evaluation of the first fragment library specifically tailored to tackle both these challenges. The 3F library of 115 fluorinated, Fsp3‐rich fragments is shape diverse and natural‐product‐like with desirable physicochemical properties. The library is perfectly suited for rapid and efficient screening by NMR spectroscopy in a two‐stage workflow of 19F NMR and subsequent 1H NMR methods. Hits against four diverse protein targets are widely distributed among the fragment scaffolds in the 3F library and a 67 % validation rate was achieved using secondary assays. This collection is the first synthetic fragment library tailor‐made for 19F NMR screening and the results demonstrate that the approach should find broad application in the FBDD community.
Fluorous Corannulenes: Ab initio Predictions and the Synthesis of sym‐Pentafluorocorannulene
Authors: Tian Xiaoqi , Xu Jun , Baldridge Kim K. , Siegel Jay S. 
Published: November 2019

AbstractTen sym‐penta and deca‐X substituted corannulenes (1–10; X=H, F, CH3, or CF3) define a library of fluorous compounds comprising high symmetry non‐planar aromatic compunds. They provide a group of structurally similar, yet physically distinct structures manifesting special chemical behavior related to their degree of fluorination. Owing to their bowl forms, corannulene derivatives are distinct from planar polynuclear aromatic compounds; they have relatively high dipole moments, accept 1–4 electrons, and display room temperature fluorescence as well as low temp phosphorescence. Electronic structure theory predicts the bowl inversion barrier and physical properties. The syntheses of sym‐pentafluorocorannulene by an efficient late stage fluorination affords a key derivative to calibrate predictions.
Gold and Carbene Relay Catalytic Enantioselective Cycloisomerization/Cyclization Reactions of Ynamides and Enals
Authors: Zhou Liejin , Wu Xingxing , Yang Xing , Mou Chengli , Song Runjiang , Yu Shuyan , Chai Huifang , Pan Lutai , Jin Zhichao , Chi Yonggui Robin 
Published: November 2019

AbstractThe combined use of gold as transition metal catalyst and N‐heterocyclic carbene (NHC) as organic catalyst in the same solution for relay catalytic reactions was disclosed. The ynamide substrate was activated by gold catalyst to form unsaturated ketimine intermediate that subsequently reacted with the enals (via azolium enolate intermediate generated with NHC) effectively to form bicyclic lactam products with excellent diastereo‐ and enantio‐selectivities. The gold and NHC coordination and dissociation can be dynamic and tunable events, and thus allow the co‐existence of both active metal and carbene organic catalysts in appreciable concentrations, for the dual catalytic reaction to proceed.
A Class of FeIII Macrocyclic Complexes with Alcohol Donor Groups as Effective T1 MRI Contrast Agents
Authors: Snyder Eric M. , Asik Didar , Abozeid Samira M. , Burgio Ariel , Bateman Gage , Turowski Steven G. , Spernyak Joseph A. , Morrow Janet R. 
Published: November 2019

AbstractEarly studies suggested that FeIII complexes cannot compete with GdIII complexes as T1 MRI contrast agents. Now it is shown that one member of a class of high‐spin macrocyclic FeIII complexes produces more intense contrast in mice kidneys and liver at 30 minutes post‐injection than does a commercially used GdIII agent and also produces similar T1 relaxivity in serum phantoms at 4.7 T and 37 °C. Comparison of four different FeIII macrocyclic complexes elucidates the factors that contribute to relaxivity in vivo including solution speciation. Variable‐temperature 17O NMR studies suggest that none of the complexes has a single, integral inner‐sphere water that exchanges rapidly on the NMR timescale. MRI studies in mice show large in vivo differences of three of the FeIII complexes that correspond, in part, to their r1 relaxivity in phantoms. Changes in overall charge of the complex modulate contrast enhancement, especially of the kidneys.
Nanoparticle Size‐Fractionation through Self‐Standing Porous Covalent Organic Framework Films
Authors: Dey Kaushik , Kunjattu H. Shebeeb , Chahande Anurag M. , Banerjee Rahul 
Published: November 2019

AbstractCovalent organic frameworks (COFs) have attracted attention due to their ordered pores leading to important industrial applications like storage and separation. Combined with their modular synthesis and pore engineering, COFs could become ideal candidates for nanoseparations. However, the fabrication of these microcrystalline powders as continuous, crack‐free, robust films remains a challenge. Herein, we report a simple, slow annealing strategy to construct centimeter‐scale COF films (Tp‐Azo and Tp‐TTA) with micrometer thickness. The as‐synthesized films are porous (SABET=2033 m2 g−1 for Tp‐Azo) and chemically stable. These COFs have distinct size cut‐offs (ca. 2.7 and ca. 1.6 nm for Tp‐Azo and Tp‐TTA, respectively), which allow the size‐selective separation of gold nanoparticles. Unlike, other conventional membranes, the durable structure of the COF films allow for excellent recyclability (up to 4 consecutive cycles) and easy recovery of the gold nanoparticles from the solution.
Triruthenium carbonyl complexes containing bidentate pyridine–alkoxide ligands for highly efficient oxidation of primary and secondary alcohols
Authors: Yue Xiaohui , Yan Xinlong , Huo Shuaicong , Dong Qing , Zhang Junhua , Hao Zhiqiang , Han Zhangang , Lin Jin 
Published: November 2019

Reactions of substituted pyridylalkanol 6‐CH3PyCH2CH(OH)R (R = Ph (L1H), R = 4‐CH3C6H4 (L2H), R = 4‐OCH3C6H4 (L3H), R = 4‐ClC6H4 (L4H), R = 4‐BrC6H4 (L5H), R = 4‐CF3C6H4 (L6H)) with Ru3(CO)12 in refluxing tetrahydrofuran afforded the corresponding ruthenium carbonyl complexes [6‐CH3PyCH2CHRO]2Ru3(CO)8 (R = Ph (1a), R = 4‐CH3C6H4 (1b), R = 4‐OCH3C6H4 (1c), R = 4‐ClC6H4 (1d), R = 4‐BrC6H4 (1e), R = 4‐CF3C6H4 (1f)) in good yields. These ruthenium complexes were well characterized using elemental analysis and Fourier transform infrared and NMR spectroscopies. Furthermore, their crystal structures were determined using single‐crystal X‐ray diffraction analysis. Complexes 1a–1f were found to be highly active toward oxidation of a wide range of primary and secondary alcohols to corresponding aldehydes and ketones within 5 minutes in the presence of N‐methylmorpholine‐N‐oxide as oxidant.
Polyphosphazenes for the delivery of biopharmaceuticals
Authors: Hsu Wei‐Hsin , Csaba Noemi , Alexander Cameron , Garcia‐Fuentes Marcos 
Published: November 2019

ABSTRACTPolyphosphazenes (PPZs) are a relatively new family of polymers based on a nitrogen–phosphorous backbone where organic side groups can be grafted. The synthetic route to PPZs is highly versatile such that it is possible to add many different functionalities that change completely the physicochemical and biological properties of the polymers. For instance, PPZs can be designed with a variety of organic side groups that render these materials biodegradable and highly biocompatible. Based on these positive features, PPZs have been explored for many biomedical applications including the design of numerous advanced drug delivery systems. In this area, PPZs have been particularly investigated as materials for the formulation of biopharmaceuticals of high added value. These include protein‐ and polynucleotide‐based medicines, applications where PPZ carriers have obtained very positive results in preclinical models. A further area of major interest for PPZs has been vaccination, where these materials have obtained excellent results in vivo as polymer adjuvants and have advanced to clinical evaluation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48688.