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Herein, we report a photocatalytic method for the synthesis of 2‐quinolones under mild conditions by employing α‐diazo acetamide as substrates. The use of Eosin Y as a photocatalyst allows an economical and environmentally benign synthetic method. The process involves the generation of radicals from diazo compounds promoted by a visible‐light‐induced proton‐coupled electron transfer (PCET) mechanism. The method demonstrates a broad substrate scope to provide various aryl‐ and alkyl‐substituted 2‐quinolones. To support the proposed mechanism, a series of mechanistic experiments were conducted. [ABSTRACT FROM AUTHOR]

For single‐atom‐layer hydrogen evolution reaction catalysts, enrichment of the 1T‐phase in monolayer molybdenum disulfide is important to achieve ideal metal utilization efficiency and exposure of active surface atoms. Herein, it is discovered that the 1T‐phase degree in monolayer MoS2 can be enhanced through sulfidation of the Pd species deposited on MoS2 (PdxSy/1T‐MoS2). Raman and X‐ray photoelectron spectroscopy reveal that the sulfidation‐assisted phase transition results in considerably greater proportions of 1T‐phase fraction (up to 86%) without using alkali‐metal‐based approaches. Observations of S‐atom displacement/translation at the atomic level contribute to the understanding of the phase transformation of MoS2. The maximized surface atom activation and metal utilization efficiency in PdxSy/1T‐MoS2 lead to unprecedentedly high mass activity (−3444 A mgPd−1) and turnover frequency (1892 s−1), three orders of magnitude higher than those of commercial Pt/C 10 wt% (3.6 A mgPt−1 and 3.6 s−1). The sulfidation‐assisted 1T‐phase enrichment has major implications for the designs of efficient electrocatalysts through MoS2 phase engineering. [ABSTRACT FROM AUTHOR]

Synthesis of heterocycles from 1,2‐diarylalkene derivatives through electrosynthesis under metal‐ and oxidant‐free conditions has been discovered. Cathodic reduction of 2‐alkenylbenzoic acid or anodic oxidation of 2‐alkenylbenzamide, 2‐alkenylphenol and 2‐alkenylaniline leads to the formation of reactive radical intermediates which afford corresponding phthalide, isochroman‐1‐one, isoindolin‐1‐one, benzofuran, and indole in satisfying yields with good functional group tolerance. Interestingly, different chemoselectivities were found in different reaction solvents. Several mechanistic investigations including cyclic voltammetry studies and control experiments were carried out to elucidate the reaction mechanisms. [ABSTRACT FROM AUTHOR]

Summary: Bismuth has garnered attention as a promising anode material for Na‐ion batteries (NIBs) because of its high volumetric capacity and appropriate operating potential. However, the large and repeated volume variations of the Bi anode during sodiation/desodiation lead to a poor electrochemical performance; thus, a rational design for Bi‐based materials is essential for their application to NIB anodes. First, the Na reaction pathway of Bi was analyzed using various cutting‐edge ex situ analysis tools. Subsequently, two different types of Bi‐based nanocomposite materials were prepared to enhance the Na storage performance of Bi: one is an amorphous carbon (a‐C)‐modified Bi nanocomposite (Bi@a‐C) fabricated via mechanical treatment and the other is a metal–organic framework (MOF)‐derived polyhedral Bi nanocomposite (p‐Bi@C) fabricated via chemical treatment. The Na storage performance of p‐Bi@C is much higher than that of Bi@a‐C because of the homogeneous anchoring effect of Bi nanocrystals in the MOF‐derived polyhedral C matrices, which have robust and high Na‐ion conduction. The p‐Bi@C delivered a highly reversible capacity (302 mAh g−1 over 100 cycles) and high rate capability (205 mAh g−1 at 2C). Therefore, this study provides a rational design of Bi‐based nanocomposite materials for application to high‐performance NIB anodes. [ABSTRACT FROM AUTHOR]

Herein, a Na quasi‐intercalation concept in black P is developed in order to achieve superior P‐based Na‐ion battery (NIB) anodes. Firstly, black P with a puckered layer structure is synthesized via a simple solid‐state reaction using commercially available red P. Additionally, an amorphous carbon modified black P nanocomposite (black P@C) is prepared to optimize its electrochemical Na reversibility. Furthermore, the Na reaction pathways of black P are demonstrated using various ex situ analytical tools. During sodiation/desodiation, black P undergoes the two‐step reactions of sequential quasi‐intercalation of NaP formation (at 0.25 V) and conversion of Na3P formation (at 0 V). Interestingly, black P@C shows poor cycling performance when using the conversion reaction, but it shows superior performance when using the quasi‐intercalation reaction between black P and NaP. Therefore, we anticipate that the Na quasi‐intercalation in black P@C will lead to high‐performance NIB anodes. [ABSTRACT FROM AUTHOR]

Oxidative [3+3] cycloadditions offer an efficient route for six‐membered‐ring formation. This approach has been realized based on an electrochemical oxidative coupling of indoles/enamines with active methylene compounds followed by tandem 6π‐electrocyclization leading to the synthesis of dihydropyrano[4,3‐b]indoles and 2,3‐dihydrofurans. The radical–radical cross‐coupling of the radical species generated by anodic oxidation combined with the cathodic generation of the base from O2 allows for mild reaction conditions for the synthesis of structurally complex heterocycles. [ABSTRACT FROM AUTHOR]

To design a high‐performance Fe2O3‐based anode for Li‐ion batteries (LIBs), Fe2O3 nanocubes (Fe2O3–NCs) and their graphite‐modified (Fe2O3–NCs–G) composite were synthesized using a simple two‐step method. The Fe2O3–NCs–G composite consisted of homogeneously distributed individual Fe2O3–NCs with graphite matrices, which were confirmed by X‐ray diffraction (XRD) and scanning electron microscopy. In addition, the Fe2O3–NCs–G composite delivered a high specific surface area and good electrical conductivity. To demonstrate the electrochemical Li insertion/extraction mechanism of the Fe2O3–NCs–G composite electrodes, ex‐situ XRD and Fe K‐edge extended X‐ray absorption fine structure analyses were performed. Because of its structural merits, the synthesized Fe2O3–NCs–G composite exhibited high electrochemical performance featuring a high reversible capacity of 865 mAh g−1 after 100 cycles and a fast rate capability, thus demonstrating its high possibility for high‐performance LIBs. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis of highly substituted quinolines has been developed based on three‐component radical cascade based on visible‐light photoredox catalysis. This tandem coupling reaction has been coordinated to proceed with high chemoselectivity based on the differential electronic properties of coupling partners. Subjection of electron‐rich β‐aminoacrylates with electron‐deficient halides and alkenes to the optimized conditions leads to the formation of quinolines in good yields after in situ oxidation of tetrahydroquinolines. Detailed mechanistic studies which reveal an unexpected reaction pathway is described. [ABSTRACT FROM AUTHOR]

Purpose: To identify the most reliable imaging features for differentiating hepatocellular carcinoma with paradoxical uptake on the hepatobiliary phase (HCCpara ) from focal nodular hyperplasia (FNH)-like nodules using Gd-EOB-DTPA-enhanced MRI.Materials and Methods: This was a retrospective study. Twenty patients with HCCpara and 21 patients with FNH-like nodules were included. The following MRI features were evaluated using 3.0 Tesla unit by two radiologists: signal intensity (SI) on T1-, T2-, and diffusion-weighted imaging (DWI), arterial enhancement pattern, washout appearance on the portal venous phase (PVP) and/or transitional phase (TP), uptake pattern on the hepatobiliary phase (HBP), "T2 scar," "EOB scar," and chemical shift on in- and out-of-phase images. Multivariate logistic regression analysis was performed to assess MRI features for prediction of HCCpara .Results: Compared with FNH-like nodules, HCCpara had significantly more frequent heterogeneous T1 SI (P < 0.0001), T2 hyperintensity (P = 0.032), heterogeneous arterial enhancement (P < 0.0001), washout appearance on the PVP and/or TP (P < 0.0001), heterogeneous uptake on the HBP (P < 0.0001), absence of "EOB scar" (P < 0.0001), and hyperintensity on DWI (P = 0.004). Multivariate logistic regression analysis revealed washout appearance as the only independent imaging feature associated with HCCpara (odds ratio, 7.019; P = 0.042). Washout appearance also showed the best diagnostic performance with a sensitivity of 90% and a specificity of 100%.Conclusion: Washout appearance on the PVP and/or TP is the most reliable imaging feature for differentiating HCCpara from FNH-like nodules.Level Of Evidence: 3 J. MAGN. RESON. IMAGING 2017;45:1599-1608. [ABSTRACT FROM AUTHOR]

We exploited the unstable characteristics of solid SnO at all temperatures to develop a simple, fast, inexpensive, and scalable method based on high-energy ball milling to transform SnO into a disproportionated nanocomposite that consists of amorphized Sn and nanocrystalline SnO2. In the first step of this process, nanostructured disproportionated SnO (d-SnO) made up of nanosized Sn and SnO2 crystallites is produced by ball milling pure SnO powder. The electrochemical performance of the d-SnO is then enhanced by creating a d-SnO/C nanocomposite through additional ball milling. This d-SnO/C nanocomposite was analyzed by various techniques, such as XRD, high-resolution transmission electron microscopy, and extended X-ray absorption fine structure analysis, and consists of amorphized Sn (≈sub-3 nm) and nanocrystalline SnO2 (≈5-15 nm) within an amorphous carbon matrix. This structure produces excellent electrochemical performances with a high initial energy density (first charge: 892 mA h g−1 or 1436 mA h cm−3), a relatively good initial Coulombic efficiency (≈73 %), long cycling stability (above 642 mA h g−1 or 1034 mA h cm−3 over 300 cycles), and a fast rate capability (3 C: 585 mA h g−1 or 942 mA h cm−3). Based on these results, we believe that d-SnO/C nanocomposite electrodes have the potential to create a new area of research in the field of high-performance Li-alloy-based anode materials. [ABSTRACT FROM AUTHOR]

Purpose To compare intravoxel incoherent motion diffusion weight imaging IVIM-DWI MRI with DMSA for the evaluation of cortical defect in pediatric upper urinary tract infection (UTI) patients. Materials and Methods Forty-three kidneys of 22 pediatric patients with the first episode of febrile upper UTI were evaluated. DWI using IVIM model was performed with eight b factors. The presence of cortical defect was evaluated on apparent diffusion coefficient (ADC) map. DMSA was used as the standard of reference. ADC, true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (F) in both defect and nondefect area were calculated and compared. Results Cortical defects were detected in 14 kidneys by IVIM-DWI. The sensitivity, specificity, positive predictive value, and negative predictive value of IVIM-DWI MRI for the detection of defects was 93.3%, 100%, 100%, and 96.5%, respectively. Mean values of ADC, D, D*, and F were 1.12 ± 0.15, 1.05 ± 0.10, 33 ± 17 (× 10−3 mm2/s), and 0.14 ± 0.09 in the defect foci. In normal foci, ADC, D, D*, and F were 1.37 ± 0.09, 1.31 ± 0.10, 43 ± 19 (× 10−3 mm2/s), and 0.12 ± 0.04, respectively. ADC and D were significantly lower in defect group than nondefect group ( P < 0.01). Conclusion IVIM-DWI can allow both direct visualization and quantitative measurement of cortical defects. J. Magn. Reson. Imaging 2014;40:545-551. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

ABSTRACT The vector decomposition problem has been considered as a hard problem, which is applicable to cryptography. Okamoto and Takashima proposed various types of public key cryptographic schemes based on the VDP. In this paper, we study the cryptographic implications of Okamoto-Takashima schemes with respect to the properties of public keys. In the public key cryptography, one public key is associated to a unique private key, and an action using the public key implicitly assumes that the corresponding private action can be done only with the corresponding private key. We formalize this security issue by introducing the notion of equivalent public keys. We show that equivalent public keys exist in the Okamoto-Takashima basic signature scheme and the homomorphic encryption scheme. We present a strong key substitution attack to their basic signature. We suggest how to prevent equivalent public keys and strong key substitution attack in their signature scheme. We point out that there are cases with no efficient methods to prevent equivalent public keys in their encryption scheme. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Soluble chemically reduced graphene oxide (RGO)/poly(4-vinyl pyridine) (P4VP) assembly was attempted by totally noncovalent approach. Chemical reduction of P4VP/GO mixture by hydrazine produced soluble RGO/P4VP assembly with long term stability. Prepared RGO/P4VP assembly showed pH-dependent variation of optical transmittance. Transmittance of RGO/P4VP assembly solution at pH 2.0 dramatically increased more than 200% of transmittance of assembly at pH 6. This optical transmittance change was fully reversible. The detailed morphological features of assemble was evaluated by dynamic light scattering (DLS) and atomic force microscopy (AFM). It is estimated that RGO/P4VP assemblies were well separated each other at pH 6, enabling much higher optical absorption of RGO plates. At pH 2, protonation of pyridine ring occurs and this might hamper effective noncovalent interaction between RGO plate and protonated P4VP chains, forming bigger aggregates having less chance for optical absorption. This pH-dependent optical modulation of RGO/P4VP assembly can be useful for the designing of pH-sensor, removable nanocatalyst, and targeted drug delivery, etc. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2538-2543, 2013 [ABSTRACT FROM AUTHOR]

By using carbon nanotubes (CNTs) as a shape template and glucose as a carbon precursor and structure-directing agent, CNT@Fe3O4@C porous core/sheath coaxial nanocables have been synthesized by a simple one-pot hydrothermal process. Neither a surfactant/ligand nor a CNT pretreatment is needed in the synthetic process. A possible growth mechanism governing the formation of this nanostructure is discussed. When used as an anode material of lithium-ion batteries, the CNT@Fe3O4@C nanocables show significantly enhanced cycling performance, high rate capability, and high Coulombic efficiency compared with pure Fe2O3 particles and Fe3O4/CNT composites. The CNT@Fe3O4@C nanocables deliver a reversible capacity of 1290 mA h g−1 after 80 cycles at a current density of 200 mA g−1, and maintain a reversible capacity of 690 mA h g−1 after 200 cycles at a current density of 2000 mA g−1. The improved lithium storage behavior can be attributed to the synergistic effect of the high electronic conductivity support and the inner CNT/outer carbon buffering matrix. [ABSTRACT FROM AUTHOR]

Aus Dreiring mach' Sechsring: Die Titelreaktion läuft unter milden Bedingungen ab und toleriert eine Bandbreite von Substituenten am resultierenden Pyridinring (siehe Schema; esp=α,α,α′,α′ ‐ Tetramethyl ‐ 1,3 ‐ benzoldipropionsäure). Die Bildung des Schlüsselintermediats ist katalysatorkontrolliert, und die anschließende Cyclisierung und Oxidation liefert die Produkte in exzellenten Ausbeuten. Die Methode wurde zur effizienten Synthese von Polyarylpyridinen verwendet. [ABSTRACT FROM AUTHOR]

ABSTRACT Redactable signature schemes permit deletion of arbitrary substrings of a signed document while preserving the authenticity of the remaining document. Most of known redactable signatures based on pairing have large-sized signatures and the sizes depend on the product of security parameter and the number of blocks of the redacted document. In this paper, we present a short redactable signature scheme based on pairing. We modify Waters signature scheme to obtain an underlying standard signature defined on composite-order bilinear group. The modified scheme satisfies the unforgeability under the known message attack based on the Computational Diffie-Hellman assumption. Based on the modified Waters signature, we propose a short redactable signature that is existentially unforgeable under random message attack and weakly private. The size of the proposed scheme is 20% of known redactable signatures using aggregated pairing-based signatures when half of the message blocks are deleted. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Disproportionation of SnO: The cover image shows a simple, fast, inexpensive, and scalable method of transforming solid tin oxide (SnO) into a Sn/SnO2/C nanocomposite, which consists of disproportionated amorphous Sn (sub 3 nm) and nanocrystalline SnO2 (5–15 nm) within an amorphous carbon matrix. Specifically, the disproportionated Sn/SnO2/C nanocomposite was developed based on the unstable characteristics of solid SnO at all temperatures. As described in the Full Paper on page 658 by Jae‐Wan Park and Cheol‐Min Park of the Kumoh National Institute of Technology, Korea, the process is aimed at obtaining high‐performance anode materials for rechargeable Li‐ion batteries. Upon use as an anode material in rechargeable Li‐ion batteries, the disproportionated Sn/SnO2/C nanocomposite showed excellent electrochemical performance, with high initial energy density, a relatively good initial coulombic efficiency, long cycling stability, and a fast rate capability. Additionally, the disproportionation reaction of SnO was thoroughly investigated using various analytical techniques, which should be of broad interest to the field of materials chemistry. [ABSTRACT FROM AUTHOR]

Mechanistic studies suggest that the pyridine formation is initiated by a 1,6-hydride shift or prototypic isomerization, depending on the type of substituents. [ABSTRACT FROM AUTHOR]