bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric Phase Based Circular Array for Multimode Vortex Beam Generation
Authors: Li Quan , Wu Chao , Liu Xuan , Zhao Song , Zhang Zhihui , Shang Xiaobing , Wei Zeyong , Li Hongqiang 
Published: November 2019

AbstractA geometric phase model for electromagnetic radiating elements is proposed. By rotation of the radiating element, a frequency‐independent geometric phase occurs for circularly polarized components of radiation field along every direction in far field. In addition, the geometric phase is equal to the rotation angle for a circularly polarized source, which enables phase modulation ranging from 0 to 2π. In contrast, the Pancharatnam–Berry phase for circular polarization conversion components brought by optical element rotation is twice the rotation angle and is applicable only for the scattering waves propagating along the rotation axis. As a proof of principle, an antenna array is designed and fabricated in microwave regime to verify the phase modulation approach. Both the calculated and measured results verify that three different orbital angular momentum modes are generated simultaneously at 8.5 GHz and 11.5 GHz.
Synergic Interplay Between Halogen Bonding and Hydrogen Bonding in the Activation of a Neutral Substrate in a Nanoconfined Space
Authors: La Manna Pellegrino , De Rosa Margherita , Talotta Carmen , Rescifina Antonio , Floresta Giuseppe , Soriente Annunziata , Gaeta Carmine , Neri Placido 
Published: November 2019

AbstractThe principle of amplified halogen bonding (XB) in a small space is exploited as a catalytic tool for the activation of an XB acceptor substrate in a nanoconfined environment. The inner cavity of the resorcinarene capsule has been equipped with an XB catalyst bearing an ammonium unit acting as a Trojan horse to drive the catalyst inside the capsule. In the presence of a specific XB catalyst, the capsule is able to catalyze a Michael reaction between N‐methylpyrrole and methyl vinyl ketone. In the bulk medium in absence of the resorcinarene capsule, the XB catalyst is catalytically ineffective. Quantum‐mechanical investigations highlight that the Michael reaction proceeds through the activation of the carbonyl group by synergistically enhanced halogen/hydrogen‐bonding interactions and takes place in an open pentameric capsule.
Host–Guest Recognition and Fluorescence of a Tetraphenylethene‐Based Octacationic Cage
Authors: Duan Honghong , Li Yawen , Li Qingfang , Wang Pinpin , Liu Xueru , Cheng Lin , Yu Yang , Cao Liping 
Published: November 2019

AbstractWe report the synthesis and characterization of a three‐dimensional tetraphenylethene‐based octacationic cage that shows host–guest recognition of polycyclic aromatic hydrocarbons (e.g. coronene) in organic media and water‐soluble dyes (e.g. sulforhodamine 101) in aqueous media through CH⋅⋅⋅π, π–π, and/or electrostatic interactions. The cage⊃coronene exhibits a cuboid internal cavity with a size of approximately 17.2×11.0×6.96 Å3and a “hamburger”‐type host–guest complex, which is hierarchically stacked into 1D nanotubes and a 3D supramolecular framework. The free cage possesses a similar cavity in the crystalline state. Furthermore, a host–guest complex formed between the octacationic cage and sulforhodamine 101 had a higher absolute quantum yield (ΦF=28.5 %), larger excitation–emission gap (Δλex‐em=211 nm), and longer emission lifetime (τ=7.0 ns) as compared to the guest (ΦF=10.5 %; Δλex‐em=11 nm;τ=4.9 ns), and purer emission (ΔλFWHM=38 nm) as compared to the host (ΔλFWHM=111 nm).
3‐O‐Sulfation of Heparan Sulfate Enhances Tau Interaction and Cellular Uptake
Authors: Zhao Jing , Zhu Yanan , Song Xuehong , Xiao Yuanyuan , Su Guowei , Liu Xinyue , Wang Zhangjie , Xu Yongmei , Liu Jian , Eliezer David , Ramlall Trudy F. , Lippens Guy , Gibson James , Zhang Fuming , Linhardt Robert J. , Wang Lianchun , Wang Chunyu 
Published: November 2019

AbstractPrion‐like transcellular spreading of tau in Alzheimer's Disease (AD) is mediated by tau binding to cell surface heparan sulfate (HS). However, the structural determinants for tau–HS interaction are not well understood. Microarray and SPR assays of structurally defined HS oligosaccharides show that a rare 3‐O‐sulfation (3‐O‐S) of HS significantly enhances tau binding. In Hs3st1−/− (HS 3‐O‐sulfotransferase‐1 knockout) cells, reduced 3‐O‐S levels of HS diminished both cell surface binding and internalization of tau. In a cell culture, the addition of a 3‐O‐S HS 12‐mer reduced both tau cell surface binding and cellular uptake. NMR titrations mapped 3‐O‐S binding sites to the microtubule binding repeat 2 (R2) and proline‐rich region 2 (PRR2) of tau. Tau is only the seventh protein currently known to recognize HS 3‐O‐sulfation. Our work demonstrates that this rare 3‐O‐sulfation enhances tau–HS binding and likely the transcellular spread of tau, providing a novel target for disease‐modifying treatment of AD and other tauopathies.
Dual Enhancement of Gold Nanocluster Electrochemiluminescence: Electrocatalytic Excitation and Aggregation‐Induced Emission
Authors: Peng Huaping , Huang Zhongnan , Deng Haohua , Wu Weihua , Huang Kaiyuan , Li Zhenglian , Chen Wei , Liu Juewen 
Published: November 2019

AbstractLigand‐protected gold nanoclusters (AuNCs) have emerged as a new class of electrochemiluminescence (ECL) luminophores for their interesting catalytic and emission properties, although their quantum yield (ΦECL) in aqueous medium is low with a poor mechanistic understanding of the ECL process. Now it is shown that drying AuNCs on electrodes enabled both enhanced electrochemical excitation by an electrocatalytic effect, and enhanced emission by aggregation‐induced ECL (AIECL) for 6‐aza‐2‐thiothymine (ATT) protected AuNCs with triethylamine (TEA) as a coreactant. The dried ATT‐AuNCs/TEA system resulted in highly stable visual ECL with a ΦECL of 78 %, and a similar enhancement was also achieved with methionine‐capped AuNCs. The drying enabled dual‐enhancement mechanism has solved a challenging mechanistic problem for AuNC ECL probes, and can guide further rational design of ECL emitters.
Chemical characterization and anti‐breast cancer effects of silver nanoparticles using Phoenix dactylifera seed ethanolic extract on 7,12‐Dimethylbenz[a] anthracene‐induced mammary gland carcinogenesis in Sprague Dawley male rats
Authors: Mohammadi Ghobad , Zangeneh Mohammad Mahdi , Zangeneh Akram , Haghighi Zahra Minoosh Siavosh 
Published: November 2019

The aim of the recent research was to investigate the anti‐breast cancer effects of silver nanoparticles using Phoenix dactylifera seed ethanolic extract (AgNPs). After preparation of Phoenix dactylifera seed extract, GC/MS was performed to detect the compounds. The findings indicated that 9‐Octadecenoic acid (Z)‐ methyl ester (40.95%) and Dodecanoic acid methyl ester (20%) were the most frequent constituents found in P. dactylifera. These nanoparticles were spherical with a size range of 17‐19 nm and characterized using various analytical techniques including UV–Vis absorption spectroscopy to determine the presence of AgNPs in the solution. We studied functional groups of P. dactylifera extract in the reduction and capping process of AgNPs by FT‐IR, crystallinity and FCC planes by X‐ray diffraction (XRD) pattern and surface morphology, shapes, and size of AgNPs by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). DPPH free radical scavenging test was used to test the antioxidant properties of P. dactylifera and AgNPs, which revealed high antioxidant potential similar to butylated hydroxy toluene (BHT) as the positive control. The results of cytotoxicity analysis indicated that P. dactylifera and AgNPs were toxic for MCF‐7 cells. In vivo design, induction of breast cancer was done by 7,12‐Dimethylbenz[a] anthracene (DMBA) in 50 animals. After 10 days, the animals were randomly divided into six subgroups, including healthy control, untreated control, two groups receiving the P. dactylifera at 2 and 6 mg/kg and two groups receiving the AgNPs at 2 and 6 mg/kg concentrations. Both doses of P. dactylifera and AgNPs (especially AgNPs6) significantly (p ≤ 0.05) reduced the weight and volume of liver, mammary gland, kidney, spleen, ALP, AST, ALT, GGT, cholesterol, LDL, triglyceride, total and conjugated bilirubin, urea, creatinine, glucose, ferrous, ferritin, erythropoietin, GR, IL1, IL6, IL12, IL18, IFNY, and TNFα and increased HDL, total protein, albumin, WBC, lymphocyte, neutrophils, platelet, RBC, Hb, PCV, MCV, MCH, MCHC, SOD, CAT, GPx, IL4, IL5, IL10, IL13, and IFNα compared to the untreated group. Moreover, P. dactylifera and AgNPs (especially AgNPs6) significantly (p ≤ 0.05) treated breast cancer with reduction of organs free of metastasis compared to the untreated group. Seemingly, the AgNPs can be used for the treatment of breast cancer.
O‐Alkyldithiophosphate Nickel Complexes with dcpf Ligand as Efficient Electrocatalysts for Hydrogen Evolution
Authors: Zhang Dong‐Liang , Deng Cheng‐Long , Xie Bin , Li Yu‐Long , Lai Chuan , Mou Wen‐Yu , He Lin‐Xin , Bai Xiao‐Xue , Li Tao , Cao Jia‐Xi , Wang Jun 
Published: November 2019

Six new O‐alkyldithiophosphate nickel complexes with dcpf ligand, [(dcpf)Ni(S2P{O}OR)] (dcpf = 1,1′‐bis (dicyclohexylphosphino)ferrocene, R = CH3 (1), CH3CH2 (2), Ph (3), 4‐MeC6H4 (4), PhCH2 (5) and PhCH2CH2 (6)), have been synthesized by the treatment of dcpf with ((RO)2PS2)2Ni in satisfactory yields. These complexes were characterized by elemental analysis, spectroscopy (FTIR, UV–vis, 1H, 13C, and 31P NMR), thermogravimetric analysis and single crystal X‐ray diffraction. The nickel atom in 1, 2·CH2Cl2, 3·CH2Cl2, 4·2CH2Cl2·THF, and 2(5)·hexane adopts a slightly distorted square‐planar coordination environment finished by two phosphorus atoms of dcpf ligand and two sulfur atoms of O‐alkyldithiophosphate ligand. Furthermore, the electrochemical properties for complexes 1–6 were also investigated by cyclic voltammetry. With the addition of 120 mM trifluoroacetic acid (TFA), the turnover frequency (TOF) values for 1–6 are estimated to be 1243.83, 1046.54, 1331.71, 2545.29, 1899.03, and 1191.37 s−1, with the overpotential (η) values of 0.62, 0.58, 0.71, 0.67, 0.60, and 0.56 V, respectively. The result of electrochemical studies indicates that all complexes can be used as efficient molecular eletrocatalysts for the reduction of protons to hydrogen in the presence of TFA in MeCN.
Effect of microscopic aggregation behavior on polymer shear resistance
Authors: Shi Leiting , Zhu Shijie , Ye Zhongbin , Xue Xinsheng , Liu Changlong , Lan Xitang 
Published: November 2019

ABSTRACTThe study of polymer aggregation behavior effect on shear resistance shed light on the synthesis of antishear polymer for oil displacement and enhances the application effect of polymer flooding. The effects of mechanical degradation on the properties of polymer solutions were studied by using partially hydrolyzed polyacrylamide (HPAM), hydrophobically modified HPAM (HMPAM), and dendritic hydrophobic associative polymers (DHAP), which are characterized by “granular,” “chain,” and “cluster” aggregation behavior, respectively. The results show that mechanical shearing can dramatically reduce the performance of polymer solution. The shearing resistance can be effectively enhanced by improving the polymer aggregation behavior. After being strongly sheared, hydrophobically associating polymers can still partially restore its network through hydrophobic association, therefore rebuild the solution viscosity. For DHAP, the broken molecular chains distribute more evenly in solution after shearing. In addition, the strength of reconstructed network structure of DHAP is better than that of HMAPM, which implies a better shear resistance. Furthermore, the hydrophobic association of linear polymers will increase their static adsorption on quartz sand. Meanwhile, DHAP with stronger spatial structure has less static adsorption, which is beneficial to maintain a higher polymer concentration in solution. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48670.
Anticorrosion and electromagnetic interference shielding behavior of candle soot‐based epoxy coating
Authors: Singh Priyanka , Chauhan Sampat Singh , Singh Gurmeet , Sharma Moolchand , Singh V. P. , Vaish Rahul 
Published: November 2019

ABSTRACTThis article presents candle soot (CS) as anticorrosion coating material for mild steel (MS) in 3.5 wt % of NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy. CS is easily available, low‐cost material, and characterized by using X‐Ray diffraction (XRD), Raman spectroscopy, UV–vis spectroscopy, Fourier‐transform infrared (FTIR), and scanning electron microscopy (SEM). CS is superhydrobhobic in nature that helps to prevent corrosion by repelling water molecules from MS surface. The electrochemical results confirmed the prevention in corrosion process for MS using candle soot‐epoxy (CS‐EP) based anticorrosion coatings. The CS‐based coatings displayed outstanding barrier properties in 3.5 wt % of NaCl solution in comparison to the neat EP coating. Different candle CS‐EP coating combinations were tested that exhibited excellent corrosion inhibition performance with highest protection increased up to 98.45% at 0.2 wt % of CS. The surface morphological studies were used to analyze the MS surface conditions in absence and presence of CS‐EP coating in 3.5 wt % of NaCl solution. CS‐EP admixtures were also tested for their shielding effectiveness in the frequency range of 8.2–12.4 GHz and it has been found that on incorporation of 0.2 wt % of CS in EP resin total shielding effectiveness (SET) increased to −5.3 dB as compared to −0.33 dB for neat EP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48675.
Serum metabolomics study of patients with allergic rhinitis
Authors: Ma Guang‐chao , Wang Tie‐shan , Wang Ji , Ma Zhi‐jie , Pu Shi‐biao 
Published: November 2019

AbstractAllergic rhinitis (AR) negatively affects the healthy lives of many individuals. Most previous studies on AR focused on the expression of cytokines, with only a few analyzing cytokine expression from a metabolomics viewpoint. Therefore, it is worthwhile to study AR at the metabolic level. Consequently, we aimed to identify differential serum biomarkers by metabolomics. In this study, the orthogonal partial least squares discriminant analysis (OPLS‐DA) model was applied to characterize the differences in serum samples collected from patients with AR and healthy volunteers. Ten metabolites (except hexadecanoic acid) were found to be altered significantly (p < .05) in the former group, according to results of principal component analysis and OPLS‐DA, indicating that these metabolites could be potential biomarkers. MetaboAnalyst 4.0 and pathway enrichment analysis showed that these changes in metabolites mainly involved three pathways, namely, porphyrin and chlorophyll metabolism, arachidonic acid metabolism, and purine metabolism. Our findings may contribute to a better understanding of the potential pathogenesis mechanisms and provide a metabolic evidence for in‐depth studies of AR.
What you should know about emphysematous vaginitis?
Authors: Tereso Andreia Filipa Batista , Granadas Joana Catarina Clemente , Baptista Marta Filipa Santos 
Published: November 2019

AbstractEmphysematous vaginitis represents a rare and self‐limited condition, which presents with vaginal discharge. Despite its benignity, it has some worrisome imaging features, which should be recognized in order to avoid unnecessary invasive procedures.
An intubated 7‐month‐old infant with a retropharyngeal abscess and multidrug‐resistant Streptococcus mitis
Authors: Watanabe Yoshihisa , Nagao Yoshiro , Endo Hisashi , Yamane Ichiro , Hirata Masaaki , Hatakeyama Kuniya 
Published: November 2019

AbstractThe profile of antimicrobial resistance (ie, antibiogram) may be disparate between children and adults. An infant developed severe deep neck infection with a multidrug‐resistant microbe. The microbe was more drug‐resistant in children than in adults, in our hospital. Treatment of a child should be guided by the antibiogram obtained from children.
Laser‐Induced Pyridinic‐Nitrogen‐Rich Defective Carbon Nanotubes for Efficient Oxygen Electrocatalysis
Authors: Yin Yuehui , Sun Xuechun , Zhou Miao , Zhao Xueru , Qin Jiayi , Qiao Shi‐Zhang , Du Xi‐Wen , Yang Jing 
Published: November 2019

AbstractDeveloping low‐cost, highly active, and stable bi‐functional oxygen reduction and evolutionreaction (ORR/OER) electrocatalysts for rechargeable metal‐air batteries has been regarded as a primary challengefor sustainable energy devices. Herein, for the first time we design and fabricate defective carbon nanotubes (CNTs) enriched with pyridinic nitrogenvia laser irradiation for oxygenelectrocatalysis. Mesopores with plentiful edges are produced on the surface of CNTs, which not only facilitate mass transfer throughout CNTs architecture, but also are favorable for the incorporation of pyridinic nitrogen serving as the active sites for ORR/OER. The as‐prepared catalyst shows dramatically enhanced catalytic activity with half‐wave potential of 0.84 V (vs. RHE) for ORR and an overpotential of 0.36 V for OER in alkaline medium. More importantly, it exhibits excellent Zinc‐air battery charge/discharge cycling stability.
Annulative Allylic Alkylation Reactions between Dual Electrophiles and Dual Nucleophiles: Applications in Complex Molecule Synthesis
Authors: Trost Barry M. , Kalnmals Christopher A. 
Published: November 2019

AbstractMetal‐catalyzed allylic alkylation reactions between dual nucleophiles and dual electrophiles represent a powerful set of methods for the synthesis of small‐, medium‐, and even large‐sized rings. Using this strategy, a handful of simple allylic diol derivatives can be transformed into a broad array of complex carbo‐ and heterocycles of varying ring sizes in just a single step. Because of their ability to rapidly generate complexity, annulative allylic alkylation reactions between dual nucleophiles and dual electrophiles have been extensively employed in the total synthesis of both natural products and pharmaceutical compounds.
Photochemical Functionalization of Helicenes
Authors: Jakubec Martin , Ghosh Indrajit , Storch Jan , König Burkhard 
Published: November 2019

AbstractHerein, a visible‐light photochemical approach for practical helicene functionalization at very mild reaction conditions is described. The photochemical reactions allow for the regiospecific and innate late‐stage functionalization of helicenes and are easily executed either through the activation of C(sp2)−Br bonds in helicenes using K2CO3 as inorganic base or direct C(sp2)−H helicene bond functionalization under oxidative photoredox reaction conditions. Overall, using these transformations six different functional groups are introduced to the helicene scaffold through C−C and four different C‐heteroatom bond‐forming reactions.
Discrete Supramolecular Stacks Based on Multinuclear Tweezer‐Type Rhodium Complexes
Authors: Guo Bei‐Bei , Azam Mohammad , AlResayes Saud I. , Lin Yue‐Jian , Jin Guo‐Xin 
Published: November 2019

AbstractBy taking advantage of self‐complementary π–π stacking and CH–π interactions, a series of discrete quadruple stacks were constructed through the self‐aggregation of U‐shaped dirhodium metallotweezer complexes featuring various planar polyaromatic ligands. By altering the conjugate stacking strength and bridging ligands, assemblies with a range of topologies were obtained, including a binuclear D‐shaped macrocycle, tetranuclear open‐ended cagelike frameworks, and duplex metallotweezer stacking structures. Furthermore, a rare stacking interaction resulting in selective C−H activation was observed during the self‐assembly process of these elaborate architectures.
Genetic Code Expansion Facilitates Position‐Selective Labeling of RNA for Biophysical Studies
Authors: Hegelein Andreas , Müller Diana , Größl Sylvester , Göbel Michael , Hengesbach Martin , Schwalbe Harald 
Published: November 2019

AbstractNature relies on reading and synthesizing the genetic code with high fidelity. Nucleic acid building blocks that are orthogonal to the canonical A‐T and G‐C base‐pairs are therefore uniquely suitable to facilitate position‐specific labeling of nucleic acids. Here, we employ the orthogonal kappa‐xanthosine‐base‐pair for in vitro transcription of labeled RNA. We devised an improved synthetic route to obtain the phosphoramidite of the deoxy‐version of the kappa nucleoside in solid phase synthesis. From this DNA template, we demonstrate the reliable incorporation of xanthosine during in vitro transcription. Using NMR spectroscopy, we show that xanthosine introduces only minor structural changes in an RNA helix. We furthermore synthesized a clickable 7‐deaza‐xanthosine, which allows to site‐specifically modify transcribed RNA molecules with fluorophores or other labels.
Memory of Chirality in Flow Electrochemistry: Fast Optimisation with DoE and Online 2D‐HPLC
Authors: Santi Micol , Seitz Jakob , Cicala Rossana , Hardwick Tomas , Ahmed Nisar , Wirth Thomas 
Published: November 2019

AbstractAmino acid derivatives undergo non‐Kolbe electrolysis to afford enantiomerically enriched α‐alkoxyamino derivatives through intermediate chiral carbenium ions. The products contain N,O‐acetals which are important structural motifs found in bioactive natural products. The reaction is performed in a continuous flow electrochemical reactor coupled to a 2D‐HPLC for immediate online analysis. This allowed a fast screening of temperature, electrode material, current, flow‐rate and concentration in a DoE approach. The combination with online HPLC demonstrates that also stereoselective reactions can benefit from a hugely accelerated optimisation by combining flow electrochemistry with multidimensional analysis.
A Practical Method for Continuous Production of sp3‐Rich Compounds from (Hetero)Aryl Halides and Redox‐Active Esters
Authors: Watanabe Eiichi , Chen Yiding , May Oliver , Ley Steven V. 
Published: November 2019

AbstractA practically useful coupling reaction between aromatic halides and redox‐active esters was realized by nickel catalysis through the use of a packed zinc bed column in continuous flow. Multiple reuse of the column showed a negligible decrease in efficiency, affording high space/time yields. A wide range of substrates, including a number of heteroaryl halides and polyfunctional materials were coupled in generally good yields. Longer‐time and larger‐scale experiments further demonstrates the robustness of the system.
Improved CO2 Uptake and Supercapacitive Energy Storage Using Heteroatom‐Rich Porous Carbons Derived from Conjugated Microporous Polyaminoanthraquinone Networks
Authors: Li Yuchao , Li Wenzhi , Cheng Zhonghua , He Yan , Li Huimin , Li Huixin , Liao Yaozu 
Published: November 2019

AbstractFunctionalized porous carbons have received increased attention in both gas and supercapacitive energy storage. We report heteroatom‐rich porous carbons derived from two conjugated microporous polyaminoanthraquinone networks via a straightforward pyrolysis pathway, showing high contents of nitrogen (N, max. 5.2 wt%) and oxygen (O, max. 8.3 wt%), uniform micropore (∼0.6 nm) and large surface area (1165 m2 g−1). In comparison to the polymer precursors, the resulting porous carbons exhibit much improved CO2 uptake capacity of 14.1 wt% at 1 bar maintaining an impressive reversible CO2 uptake after 50 times use. More importantly, they can be applied for efficient supercapacitors with high energy storage capacity (200 F g−1 at 0.5 A g−1), fast charge/discharge rate (charge to 158 F g−1 with only 25 s), and excellent stability (retain 98.5% capacity after 6000 cycles).