bluuebunny/crossref_metadata_2025_split huggingface dataset:
Familial dilated cardiomyopathy associated with pathogenic TBX5 variants: Expanding the cardiac phenotype associated with Holt–Oram syndrome
Authors: Patterson Jenny , Coats Caroline , McGowan Ruth 
Published: May 2020

AbstractHolt–Oram syndrome (HOS) is a rare, autosomal dominant disorder caused by heterozygous pathogenic variants in cardiac T‐box transcription factor, TBX5. Classically, it is associated with upper limb malformations and variable cardiac abnormalities. Limb manifestations are considered to be invariably present, ranging in severity from limitation in movement, to triphalangeal thumbs, absent thumbs, shortened forearms, or phocomelia. Cardiac involvement is characterized by congenital heart defects, most commonly septal structural malformations, and conduction system disease. Recently, novel TBX5 variants have also been reported in association with dilated cardiomyopathy (DCM). In this context, we report eight individuals from four unrelated families, in whom pathogenic variants in TBX5 segregated with an atypical HOS phenotype. Affected individuals exhibit relatively mild skeletal features of HOS, with a predominant cardiac phenotype, which includes several individuals affected by non‐ischaemic DCM. To our knowledge, these represent the first reported cases of DCM in families with skeletal features of HOS, some of whom also harbored variants previously linked to a classical HOS phenotype (p. Arg279* and p.Arg237Gln). This finding supports diverse roles of TBX5 in cardiovascular development and function, and confirms the importance of long‐term cardiac surveillance for individuals affected by HOS. Furthermore, these families highlight the wide phenotypic variability of HOS, which may include comparatively mild upper limb findings in respect to cardiac manifestations.
A Diselenide Turn‐On Fluorescent Probe for the Detection of Thioredoxin Reductase
Authors: Mafireyi Tendai J. , Laws Madeleine , Bassett John W. , Cassidy Pamela B. , Escobedo Jorge O. , Strongin Robert M. 
Published: May 2020

AbstractWe report the first diselenide‐based probe for the selective detection of thioredoxin reductase (TrxR), an enzyme commonly overexpressed in melanomas. The probe design involves conjugation of a seminaphthorhodafluor dye with a diselenide moiety. TrxR reduces the diselenide bond, triggering a fluorescence turn‐on response of the probe. Kinetic studies reveal favorable binding of the probe with TrxR with a Michaelis–Menten constant (Km) of 15.89 μm. Computational docking simulations predict a greater binding affinity to the TrxR active site in comparison to its disulfide analogue. In vitro imaging studies further confirmed the diselenide probe exhibited improved signaling of TrxR activity compared to the disulfide analogue.
Copper 1,19‐Diaza‐21,24‐dicarbacorrole: A Corrole Analogue with an N−N Linkage Stabilizes a Ground‐State Singlet Organocopper Species
Authors: Basumatary Biju , Hashiguchi Ikuho , Mori Shigeki , Shimizu Soji , Ishida Masatoshi , Furuta Hiroyuki 
Published: May 2020

AbstractA copper complex of a heterocorrole analogue with an N–N linkage, 1,19‐diaza‐21,24‐dicarbadibenzocorrole (Cu‐5), was successfully synthesized via oxidative metalation–cyclization of a tetrapyrrolic precursor. The N–N linkage in the skeleton of Cu‐5, which serves as a mediator of π‐electron delocalization, features an 18π aromatic system. The electronic structure of Cu‐5 is best described as a ground‐state singlet species stabilized by the distinct NNCC coordination core. This finding shows how the ligand's design can be used to modulate the Cu
orbital energy, thereby making such compounds invaluable for copper‐based catalytic applications.
Three‐Dimensional Chemically Stable Covalent Organic Frameworks through Hydrophobic Engineering
Authors: Ma Yunchao , Wang Yujie , Li Hui , Guan Xinyu , Li Baoju , Xue Ming , Yan Yushan , Valtchev Valentin , Qiu Shilun , Fang Qianrong 
Published: May 2020

AbstractThe development of three‐dimensional (3D) covalent organic frameworks (COFs) with high chemical stability is of critical importance for their practical use. In this work, it is demonstrated that the stability of 3D COFs can be improved by periodic decoration of isopropyl groups on their backbones. Owing to the strong hydrophobicity of the alkyl groups, the resultant COFs show high crystallinity, permanent pores, and exceptional stability in harsh environments, such as strong acids (3 m HCl or 3 m H2SO4 for one week), a strong base (20 m NaOH for one week), and boiling water (100 °C for one month). Furthermore, these highly stable and hydrophobic COFs display excellent oil/water separation performance with >99 % separation efficiency over a wide pH range. This work demonstrates the use of alkyl decoration in 3D COFs to tune their chemical stability and expand their potential applications.
Facettierte verzweigte Nickel‐Nanopartikel mit variierbarer Verzweigungslänge für die hochaktive elektrokatalytische Oxidation von Biomasse
Authors: Poerwoprajitno Agus R. , Gloag Lucy , Watt John , Cychy Steffen , Cheong Soshan , Kumar Priyank V. , Benedetti Tania M. , Deng Chen , Wu Kuang‐Hsu , Marjo Christopher E. , Huber Dale L. , Muhler Martin , Gooding J. Justin , Schuhmann Wolfgang , Wang Da‐Wei , Tilley Richard D. 
Published: May 2020

AbstractDie Kontrolle der Bildung von verzweigten Nanopartikeln mit hoher Homogenität ist eine der größten Herausforderungen bei der Herstellung von Nanokatalysatoren mit verbesserter Aktivität und Stabilität. Mithilfe eines Mechanismus unter Nutzung eines kubischen Kerns und hexagonaler Verzweigung zur Bildung hochgradig monodisperser verzweigter Nanopartikel wurde die Länge der Nickelverzweigungen variiert. Es hat sich gezeigt, dass die Verlängerung der Nickelzweige mit ihrer hohen Bedeckung der aktiven Facetten die Aktivität für die elektrokatalytische Oxidation von 5‐Hydroxymethylfurfural (HMF) als Beispiel für die Umwandlung von Biomasse verbessert.
Boosting Low‐Valent Aluminum(I) Reactivity with a Potassium Reagent
Authors: Grams Samuel , Eyselein Jonathan , Langer Jens , Färber Christian , Harder Sjoerd 
Published: May 2020

AbstractThe reagent RK [R=CH(SiMe3)2 or N(SiMe3)2] was expected to react with the low‐valent (DIPPBDI)Al (DIPPBDI=HC[C(Me)N(DIPP)]2, DIPP=2,6‐iPr‐phenyl) to give [(DIPPBDI)AlR]−K+. However, deprotonation of the Me group in the ligand backbone was observed and [H2C=C(N‐DIPP)−C(H)=C(Me)−N−DIPP]Al−K+ (1) crystallized as a bright‐yellow product (73 %). Like most anionic AlI complexes, 1 forms a dimer in which formally negatively charged Al centers are bridged by K+ ions, showing strong K+⋅⋅⋅DIPP interactions. The rather short Al–K bonds [3.499(1)–3.588(1) Å] indicate tight bonding of the dimer. According to DOSY NMR analysis, 1 is dimeric in C6H6 and monomeric in THF, but slowly reacts with both solvents. In reaction with C6H6, two C−H bond activations are observed and a product with a para‐phenylene moiety was exclusively isolated. DFT calculations confirm that the Al center in 1 is more reactive than that in (DIPPBDI)Al. Calculations show that both AlI and K+ work in concert and determines the reactivity of 1.
Oxidation, Coordination, and Nickel‐Mediated Deconstruction of a Highly Electron‐Rich Diboron Analogue of 1,3,5‐Hexatriene
Authors: Hermann Alexander , Fantuzzi Felipe , Arrowsmith Merle , Zorn Theresa , Krummenacher Ivo , Ritschel Benedikt , Radacki Krzysztof , Engels Bernd , Braunschweig Holger 
Published: May 2020

AbstractThe reductive coupling of an N‐heterocyclic carbene (NHC) stabilized (dibromo)vinylborane yields a 1,2‐divinyldiborene, which, although isoelectronic to a 1,3,5‐triene, displays no extended π conjugation because of twisting of the C2B2C2 chain. While this divinyldiborene coordinates to copper(I) and platinum(0) in an η2‐B2 and η4‐C2B2 fashion, respectively, it undergoes a complex rearrangement to an η4‐1,3‐diborete upon complexation with nickel(0).
Nickel‐Catalyzed Allylmethylation of Alkynes with Allylic Alcohols and AlMe3: Facile Access to Skipped Dienes and Trienes
Authors: Li Wanfang , Yu Shun , Li Jincan , Zhao Yu 
Published: May 2020

AbstractWe present herein an unprecedented allylative dicarbofunctionalization of alkynes with allylic alcohols. This simple catalytic procedure utilizes commercially available Ni(COD)2, triphenylphosphine, and inexpensive reagents, and delivers valuable skipped dienes and trienes with an all‐carbon tetrasubstituted alkene unit in a highly stereoselective fashion. Preliminary mechanistic studies support the reaction pathway of allylnickelation followed by transmetalation in this dicarbofunctionalization of alkynes.
Manganese‐Catalyzed anti‐Selective Asymmetric Hydrogenation of α‐Substituted β‐Ketoamides
Authors: Zhang Linli , Wang Zheng , Han Zhaobin , Ding Kuiling 
Published: May 2020

AbstractA Mn‐catalyzed diastereo‐ and enantioselective hydrogenation of α‐substituted β‐ketoamides has been realized for the first time under dynamic kinetic resolution conditions. anti‐α‐Substituted β‐hydroxy amides, which are useful building blocks for the synthesis of bioactive molecules and chiral drugs, were prepared in high yields with excellent selectivity (up to >99 % dr and >99 % ee) and unprecedentedly high activity (TON up to 10000). The origin of the excellent stereoselectivity was clarified by DFT calculations.
Cost‐effective and Efficient Catalyst of Bimetallic Nickel Iron Selenide toward Oxygen Evolution Reaction
Authors: Wei Pengkun , Hao Zewei , Kang Hongzhi , Yang  , Guo Donggang , Liu Lu 
Published: May 2020

AbstractThe incorporation of additional metal to form homo/heterojunction nanomaterials may enhance electrical conductivity and electrocatalytic performance. In this work, a novel Ni−Fe‐Se compound made through a facile solvothermal method with the presence of D‐(+)‐glucose (labeled as Ni0.5Fe0.5Se2/C) exhibited outstanding catalytic activity toward water oxidation. During oxygen evolution reaction (OER) process in alkaline condition, Ni0.5Fe0.5Se2/C catalyst shows an overpotential of 254 mV at 10 mA cm−2, 77 mV lower than that of the commercial RuO2, and an excellent stability.
Stereo‐ and Regioselective Cu‐Catalyzed Hydroboration of Alkynyl Chalcogenoethers
Authors: de Oliveira Isadora M. , Esteves Henrique A. , Darbem Mariana P. , Sartorelli Arthur , Correra Thiago C. , Rodrigues‐Oliveira André F. , Pimenta Daniel C. , Zukerman‐Schpector Julio , Manarin Flávia , Stefani Hélio A. 
Published: May 2020

AbstractA mild stereo‐ and regioselective Cu‐catalyzed hydroboration method for the synthesis of (Z)‐seleno‐alkenyl boronates and (Z)‐thio‐alkenylboronates from internal alkynes in the presence of commercially available B2pin2 is presented. This highly selective transformation relies on the use of N‐heterocyclic carbene (NHC) complex IPrCuCl as the active catalytic species. We also explore the functionalization of the alkenylboronates obtained via oxidation to give α‐chalcogeno ketones, useful building blocks for the synthesis of more complex chalcogen‐containing molecules.
Biosynthetic Approaches towards the Design of Artificial Hydrogen‐Evolution Catalysts
Authors: Prasad Pallavi , Selvan Dhanashree , Chakraborty Saumen 
Published: May 2020

AbstractHydrogen is a clean and sustainable form of fuel that can minimize our heavy dependence on fossil fuels as the primary energy source. The need of finding greener ways to generate H2 gas has ignited interest in the research community to synthesize catalysts that can produce H2 by the reduction of H+. The natural H2 producing enzymes hydrogenases have served as an inspiration to produce catalytic metal centers akin to these native enzymes. In this article we describe recent advances in the design of a unique class of artificial hydrogen evolving catalysts that combine the features of the active site metal(s) surrounded by a polypeptide component. The examples of these biosynthetic catalysts discussed here include i) assemblies of synthetic cofactors with native proteins; ii) peptide‐appended synthetic complexes; iii) substitution of native cofactors with non‐native cofactors; iv) metal substitution from rubredoxin; and v) a reengineered Cu storage protein into a Ni binding protein. Aspects of key design considerations in the construction of these artificial biocatalysts and insights gained into their chemical reactivity are discussed.
Exploring Multi‐Subsite Binding Pockets in Proteins: DEEP‐STD NMR Fingerprinting and Molecular Dynamics Unveil a Cryptic Subsite at the GM1 Binding Pocket of Cholera Toxin B
Authors: Monaco Serena , Walpole Samuel , Doukani Hassan , Nepravishta Ridvan , Martínez‐Bailén Macarena , Carmona Ana T. , Ramos‐Soriano Javier , Bergström Maria , Robina Inmaculada , Angulo Jesus 
Published: May 2020

AbstractLigand‐based NMR techniques to study protein–ligand interactions are potent tools in drug design. Saturation transfer difference (STD) NMR spectroscopy stands out as one of the most versatile techniques, allowing screening of fragments libraries and providing structural information on binding modes. Recently, it has been shown that a multi‐frequency STD NMR approach, differential epitope mapping (DEEP)‐STD NMR, can provide additional information on the orientation of small ligands within the binding pocket. Here, the approach is extended to a so‐called DEEP‐STD NMR fingerprinting technique to explore the binding subsites of cholera toxin subunit B (CTB). To that aim, the synthesis of a set of new ligands is presented, which have been subject to a thorough study of their interactions with CTB by weak affinity chromatography (WAC) and NMR spectroscopy. Remarkably, the combination of DEEP‐STD NMR fingerprinting and Hamiltonian replica exchange molecular dynamics has proved to be an excellent approach to explore the geometry, flexibility, and ligand occupancy of multi‐subsite binding pockets. In the particular case of CTB, it allowed the existence of a hitherto unknown binding subsite adjacent to the GM1 binding pocket to be revealed, paving the way to the design of novel leads for inhibition of this relevant toxin.
Photoredox/Cobalt Dual‐Catalyzed Decarboxylative Elimination of Carboxylic Acids: Development and Mechanistic Insight
Authors: Cartwright Kaitie C. , Joseph Ebbin , Comadoll Chelsea G. , Tunge Jon A. 
Published: May 2020

AbstractRecently, dual‐catalytic strategies towards the decarboxylative elimination of carboxylic acids have gained attention. Our lab previously reported a photoredox/cobaloxime dual catalytic method that allows the synthesis of enamides and enecarbamates directly from N‐acyl amino acids and avoids the use of any stoichiometric reagents. Further development, detailed herein, has improved upon this transformation's utility and further experimentation has provided new insights into the reaction mechanism. These new developments and insights are anticipated to aid in the expansion of photoredox/cobalt dual‐catalytic systems.
α‐Amidoaldehydes as Substrates in Rhodium‐Catalyzed Intermolecular Alkyne Hydroacylation: The Synthesis of α‐Amidoketones
Authors: Pal Ritashree , O'Brien Sean C. , Willis Michael C. 
Published: May 2020

AbstractWe show that readily available α‐amidoaldehydes are effective substrates for intermolecular Rh‐catalyzed alkyne hydroacylation reactions. The catalyst [Rh(dppe)(C6H5F)][BArF4] provides good reactivity, and allows a broad range of aldehydes and alkynes to be used as substrates, delivering α‐amidoketone products. High yields and high levels of regioselectivity are achieved. The use of α‐amidoaldehydes as substrates establishes that 1,4‐dicarbonyl motifs can be used as controlling groups in Rh‐catalyzed hydroacylation reactions.
Cu Nanoparticles Embedded in N‐Doped Carbon Materials for Oxygen Reduction Reaction
Authors: Wen Xudong , Qi Hui , Cheng Yan , Zhang Qiaoqiao , Hou Changmin , Guan Jingqi 
Published: May 2020

Summary of main observation and conclusionDevelopment of eco‐friendly, cost‐effective, and high‐performance electrocatalysts to replace precious metal platinum for oxygen reduction reaction (ORR) has received increasing attention. Herein, we adopt a facile one‐pot strategy to embed Cu nanoparticles onto N‐doped carbon‐graphene (Cu@NC‐700). The Cu@NC‐700 exhibits robust and efficient ORR catalysis with positive half‐wave potential (~0.86 V vs. RHE) and low Tafel slope (33.9 mV∙dec–1) in 0.1 M KOH solution. Meanwhile, it manifests remarkable electrochemical stability, and strong tolerance to methanol crossover and carbon monoxide poisoning. The synergistic effect between Cu‐N‐C sites, Cu nanoparticles, and N‐doped carbon support speeds up ORR electrocatalysis.
Distribution and localization of phosphatidylinositol 5‐phosphate, 4‐kinase alpha and beta in the brain
Authors: Noch Evan K. , Yim Isaiah , Milner Teresa A. , Cantley Lewis C. 
Published: May 2020

AbstractPhosphatidylinositol‐4,5‐bisphosphate (PI‐4,5‐P2) is critical for synaptic vesicle docking and fusion and generation of the second messengers, diacylglycerol and inositol‐1,4,5‐trisphosphate. PI‐4,5‐P2 can be generated by two families of kinases: type 1 phosphatidylinositol‐4‐phosphate 5‐kinases, encoded by PIP5K1A, PIP5K1B and PIP5K1C, and type 2 phosphatidylinositol‐5‐phosphate 4‐kinases, encoded by PIP4K2A, PIP4K2B, and PIP4K2C. While the roles of the type 1 enzymes in brain function have been extensively studied, the roles of the type 2 enzymes are poorly understood. Using selective antibodies validated by genetic deletion of pip4k2a or pip4k2b in mouse brain, we characterized the location of the enzymes, PI5P4Kα and PI5P4Kβ, encoded by these genes. In mice, we demonstrate that PI5P4Kα is expressed in adulthood, whereas PI5P4Kβ is expressed early in development. PI5P4Kα localizes to white matter tracts, especially the corpus callosum, and at a low level in neurons, while PI5P4Kβ is expressed in neuronal populations, especially hippocampus and cortex. Dual labeling studies demonstrate that PI5P4Kα co‐localizes with the oligodendrocyte marker, Olig2, whereas PI5P4Kβ co‐localizes with the neuronal marker, NeuN. Ultrastructural analysis demonstrates that both kinases are contained in axon terminals and dendritic spines adjacent to the synaptic membrane, which support a potential role in synaptic transmission. Immunoperoxidase analysis of macaque and human brain tissue demonstrate a conserved pattern for PI5P4Kα and PI5P4Kβ. These results highlight the diverse cell‐autonomous expression of PI5P4Kα and PI5P4Kβ and support further exploration into their role in synaptic function in the brain.
Dynamics of the fragile X mental retardation protein correlates with cellular and synaptic properties in primary auditory neurons following afferent deprivation
Authors: Yu Xiaoyan , Wang Xiaoyu , Sakano Hitomi , Zorio Diego A. R. , Wang Yuan 
Published: May 2020

AbstractAfferent activity dynamically regulates neuronal properties and connectivity in the central nervous system. The Fragile X mental retardation protein (FMRP) is an RNA‐binding protein that regulates cellular and synaptic properties in an activity‐dependent manner. Whether and how FMRP level and localization are regulated by afferent input remains sparsely examined and how such regulation is associated with neuronal response to changes in sensory input is unknown. We characterized changes in FMRP level and localization in the chicken nucleus magnocellularis (NM), a primary cochlear nucleus, following afferent deprivation by unilateral cochlea removal. We observed rapid (within 2 hr) aggregation of FMRP immunoreactivity into large granular structures in a subset of deafferented NM neurons. Neurons that exhibited persistent FMRP aggregation at 12–24 hr eventually lost cytoplasmic Nissl substance, indicating cell death. A week later, FMRP expression in surviving neurons regained its homeostasis, with a slightly reduced immunostaining intensity and enhanced heterogeneity. Correlation analyses under the homeostatic status (7–14 days) revealed that neurons expressing relatively more FMRP had a higher capability of maintaining cell body size and ribosomal activity, as well as a better ability to detach inactive presynaptic terminals. Additionally, the intensity of an inhibitory postsynaptic protein, gephyrin, was reduced following deafferentation and was positively correlated with FMRP intensity, implicating an involvement of FMRP in synaptic dynamics in response to reduced afferent inputs. Collectively, this study demonstrates that afferent input regulates FMRP expression and localization in ways associated with multiple types of neuronal responses and synaptic rearrangements.
Separation and Detection of meta‐ and ortho‐Substituted Benzene Isomers by Using a Water‐Soluble Pillar[5]arene
Authors: Zhang Gengwu , Moosa Basem , Chen Aiping , Khashab Niveen M. 
Published: May 2020

AbstractEfficient and energy‐saving separation of benzene isomers bearing a diverse range of functional groups is a great challenge due to their overlapping physicochemical properties. Here, we report the successfully use of a water‐soluble pillar[5]arene (WP5) as a multifunctional material for the separation and detection of meta/ortho‐substituted benzene isomers in water. A liquid‐liquid extraction strategy was used for the separation of these benzene isomers based on their different affinity for WP5 in water. The selectivities for the meta over the ortho isomer for xylenes, chlorotoluene, and bromotoluene was 88.6 %, 88.3 %, and 95.0 % respectively, in one extraction cycle. Furthermore, a fluorescence indicator system based on WP5 and a fluorescent dye molecule (10‐methylacridinium, D) was adopted and exhibited significant fluorescence and optical discrimination upon the addition of meta‐ compared to ortho‐xylene, which implies that a simple “turn‐on” detection can be performed prior to engaging in the separation process.
Nozzle‐Assisted Simultaneous Precipitation Method for Energetic FOX‐7/RDX Composite Microspheres with Improved Thermal Stability and Sensitivity
Authors: Xu Ruixuan , An Chongwei , Ye Baoyun , Liu Qian , Wang Jiechao , Wang Jingyu 
Published: May 2020

AbstractEnergetic 1,1‐diamino‐2,2‐dinitroethylene/hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (FOX‐7/RDX) composite crystals are fabricated via a newly introduced method named nozzle‐assisted simultaneous precipitation. Dimethyl sulfoxide is used as the solvent and FOX‐7/RDX composite crystals are prepared at different molar ratios of FOX‐7 and RDX. Regularly spherical FOX‐7/RDX particles are obtained under the 1:1 molar ratio of FOX‐7 and RDX and confirmed by field emission scanning electron microscopy. The result characterized by a laser particle size analyzer shows that the FOX‐7/RDX composite particles have a narrow particle size distribution with a median diameter of ≈1.57 µm. The structure of FOX‐7/RDX particles is confirmed using powder X‐ray diffraction and Fourier transform infrared spectroscopy, and the patterns suggest differences compared with FOX‐7/RDX mixture by mechanical mixing. Differential scanning calorimetry and thermal gravimetric test show an advanced decomposition peak temperature compared with raw FOX‐7 and RDX, and the apparent activation energy (Ea) of FOX‐7/RDX composite particles increases by 72.44 kJ mol−1 than that of raw RDX. Furthermore, the characteristic drop height of FOX‐7/RDX composite particles increases to 61.9 cm, which is a 111.3% increasement compared to raw RDX, indicating an obviously significant improvement concerning mechanical safety.