bluuebunny/crossref_metadata_2025_split huggingface dataset:
MnCo2O4 Anchored on Nitrogen‐Doped Carbon Nanomaterials as an Efficient Electrocatalyst for Oxygen Reduction
Authors: Fu Wei , Wang Xiu‐Li , Yang Xin‐Xin , He Xing‐Quan 
Published: April 2018

AbstractThe hybrids composed of N‐doped carbon (N−C) and transition‐metal‐based nanoparticles have attracted tremendous interest due to their outstanding catalytic performance for oxygen reduction reaction (ORR). Herein, we first synthesize a N−C nanomaterial by pyrolyzing the mesoporous‐silica‐protected zeolitic imidazolate framework‐8 (ZIF‐8). The synthesis involves formation of ZIF‐8@SiO2 core‐shell structure, thermal annealing in Ar and acid etching. Then, the MnCo2O4 nanoparticles are supported on the as‐synthesized N−C via a facile solvothermal method. The obtained hybrid of MnCo2O4 and N−C (MnCo2O4/N−C) exhibits better ORR activity than other as‐prepared contrast materials in terms of more positive half‐wave potential and larger diffusion‐limiting current density, close to the commercial Pt/C. Moreover, the MnCo2O4/N−C catalyst also shows better methanol tolerance and better operational stability than the benchmark Pt/C catalyst. The superior performance of MnCo2O4/N−C is attributed to its porous structure and large BET surface area, N‐doping effect, small size MnCo2O4 nanoparticles loaded on the porous N−C and synergistic effects between the doped active species. Therefore, it is expected to replace Pt/C as a promising fuel cell catalyst in alkaline direct methanol fuel cells.
Methylation Mediated Anharmonic Vibrational Signature of Nucleobases: A Case Study of Uracil and Thymine
Authors: Wang Guixiu , Li Fenghai , Zhao Juan , Wu Yifang , Wang Jianping 
Published: April 2018

AbstractThe vibrational spectra of uracil and thymine in the frequency range of 1600 − 1800 cm−1, which mainly contains the C=C and C=O stretching vibration modes, are found to be distinct due to a simple insertion of a methyl group. The nature of these vibrational modes in both molecules was examined through linear infrared spectroscopy and DFT calculations. Anharmonic calculation reveals a generally stronger couplings between pair‐wise C=O modes and also between C=O and C=C modes in uracil than in thymine, agreeing reasonably with previously reported two‐dimensional infrared experimental results. Vibrational transition density cube and vibrational potential energy distributions analyses suggest that methylation causes more localization of the carbonyl stretching modes in thymine, which is the main reason of the observed spectral differences between the two molecules.
Growth and Properties of Defect‐Chalcopyrite CdGa2Se4 Crystals
Authors: Wang Zhenyou , Wu Haixin , Ni Youbao B. , Huang Changbao , Mao Mingsheng , Chen Shijing , Ma Jiaren 
Published: April 2018

AbstractCdGa2Se4 crystal, with the structure of defect‐chalcopyrite, is a promising optical and photoelectric material. Single crystal with size of Φ11×60 mm3 was grown successfully by vertical Bridgman method. The as‐grown crystal was characterized with X‐ray diffraction (XRD), energy dispersive X‐ray Spectroscopy (EDS), and transmission spectra etc. The results show that the crystalline quality of the crystal is very good, and the atomic ratio is Cd:Ga:Se=1:2.12:4.05, which is close to the ideal stoichiometry. The crystalline quality and the chemical composition of the cracked section near the end of the crystal were also measured and the cracking reason was analyzed. The transparency range of the crystal was revealed for the first time. The transmittance of a 3.6 mm sample is above 65% in the range of 5 to 12 μm, which demonstrate the high optical quality of the crystal. Based on the transmission spectra, the refractive index and the energy bandgap were calculated to be 2.5 and 1.97 eV respectively.
Enhancing High‐Rate Capability by Introducing Phosphonate Functionalized Imidazolium Ionic Liquid into Organic Carbonate Electrolyte
Authors: Zhao Kun , Liang Hongze , Zhou Mingjiong , Zhang Gongjun , Zhao Chuanli , Ge Jiawen , Xia Yonggao , Gao Zhanghua 
Published: April 2018

AbstractA phosphonate functionalized imidazolium ionic liquid (PFIL) is synthesized and studied as an electrolyte additive for lithium ion batteries. The Li/LiFePO4 cells with addition of PFIL shows superior electrochemical performance, including an increased initial Coulombic efficiency, better capacity retention, and improved rate capability. The electrochemical mechanism of PFIL used in high‐performance batteries is investigated by using fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Our experimental result reveals that the phosphonate groups are stronger donors than carbonate groups, thus change the solvation environment of lithium ions by competitive coordination, assisting the transferring of lithium ions. Therefore, an excellent cyclability and superior rate capability with PFIL‐based electrolyte could be explained by enhanced mobility lithium ions via coordination to phosphonate groups on imidazolium cations. This work displays that PFIL‐based electrolyte systems can be considerable potential candidates for the applications in high‐performance Li‐ion batteries.
6‐Arylamino‐2,2′‐bipyridine “Push‐Pull” Fluorophores: Solvent‐Free Synthesis and Photophysical Studies
Authors: Kopchuk Dmitry S. , Krinochkin Alexey P. , Starnovskaya Ekaterina S. , Shtaitz Yaroslav K. , Khasanov Albert F. , Taniya Olga S. , Santra Sougata , Zyryanov Grigory V. , Majee Adinath , Rusinov Vladimir L. , Chupakhin Oleg N. 
Published: April 2018

AbstractThis work describes a solvent‐free approach towards “push‐pull” fluorophores based on 5‐aryl‐2,2′‐bipyridines bearing the residues of various anilines at the α‐position of the edge pyridine cycle. We have also studied the possibility of varying (het)aromatic‐substituents at C5 position of the resulted 2,2′‐bipyridines as well as the substituents in the aniline residues. The structures of products were confirmed based on the1H and13C NMR spectroscopic data, mass spectrometry, elemental analysis and X‐ray diffraction analysis. The photophysical features of the synthesized compounds have been investigated. The fluorescence emission of two key compounds was studied in solvents by varying polarities. It was demonstrated that an increase in the solvent polarity led to an increase in the Stokes shift. The linear dependence of the Stokes shift of the fluorophores on the increasing of the solvent nature was demonstrated by using the Lippert–Mataga plot. The fluorescence quenching response of the fluorophores towards metal cations was also demonstrated.
Synthesis and Photophysical Properties of α‐Pyrone‐fused‐pyrido[3, 2,1‐jk]carbazolone Derivatives : DFT/TD‐DFT Insights
Authors: Ahuja Monika , Biswas Soumen , Sharma Pratibha , Samanta Sampak 
Published: April 2018

AbstractThe present paper discloses an interesting microwave‐assisted solvent‐free protocol for the synthesis of thermally stable, highly fluorescent pyrano[2′, 3′:4,5]pyrido[3, 2,1‐jk]carbazole‐5,8‐diones in good to high yields with good quantum yields (Ø ≥ 0.70) through a [3+3] annulation reaction of aryl‐substituted Morita‐Baylis‐Hillman acetates with a 4‐hydroxy‐6H‐pyrido[3, 2,1‐jk]carbazol‐6‐one in the presence of Hünig's base. The solvatochromic properties of synthesized compounds have been determined which showed blue shifts in absorption and emission spectra with increasing the polarity of solvents. Similarly, the higher quantum yields were also observed in case of non‐polar solvents as compared to polar ones. Interestingly, the experimental results of photophysical properties were in good agreement with theoretical data obtained using B3LYP/6‐311G++(d,p) level of theory. Furthermore, the synthesized chromophoric scaffolds exhibited good thermal stability (342‐387 °C) and average fluorescence lifetime in the range of 2.011‐2.139 ns for 408 nm, 2.268‐2.277 ns for 428 nm.
Hydrogenation of Nickel Octaethylporphyrin over Dispersed MoS2 Catalysts Formed In Situ
Authors: Liu He , Wang Jian , Wang Zongxian , Fan Shiguang , Chen Kun 
Published: April 2018

AbstractHydrogenation of nickel octaethylporphyrin (Ni‐OEP) over dispersed MoS2 catalysts was studied in a batch autoclave at relatively low temperatures ranging from 553 K to 593 K. In spite of the transformation of catalytic species, invariant rate constants are acceptable to analyze the kinetics in the given temperature range. It turns out that the first hydrogenation of Ni‐OEP is the rate limiting step when the dispersed catalysts are present. With the combined analysis of XRD and XPS patterns, Ni species deposited on the surface of the catalysts were determined. As much as 66.7% of nickel exists in the mixed “NiMoS” phase, and a small amount of sulfided phase of nickel is implied. The influence of metal deposits on the catalytic activity of catalysts for hydrogenation was evaluated using anthracene as the model compounds. The conversion of anthracene over MoS2 shows to be promoted with Ni‐OEP added. It is suggested that Ni‐OEP could be hydrogenated and involved with the formation of active catalytic species. As a result, Ni‐OEP could cooperate with the dispersed MoS2 catalyst for catalyzing the anthracene hydrogenation.
Tumor Microenvironment Responsive Oxygen‐Self‐Generating Nanoplatform for Dual‐Imaging Guided Photodynamic and Photothermal Therapy
Authors: Yin Zhihui , Chen Dapeng , Zou Jianhua , Shao Jinjun , Tang Hao , Xu Hong , Si Weili , Dong Xiaochen 
Published: April 2018

AbstractDeveloping a smart nanoplatform for cancer diagnosis and treatment under the hypoxic and acidic tumor microenvironment (TME) remains a great challenge. Herein, a TME responsive Ce6‐MnO2/CNTs (CMCs) nanoplatform with oxygen‐self‐generation property and enhanced permeability and retention effect (EPR) has been successfully prepared for synergistic photothermal/photodynamic therapy. Carbon nanotubes (CNTs) were uniformly coated with cross‐linked MnO2 flakes, then the obtained MnO2/CNTs (MCs) were incubated with Chlorin e6 (Ce6) to fabricate CMCs. In the TME, MnO2 in CMCs (targeted accumulation in tumor site) could react with endogenous H2O2 and H+ to supply oxygen in situ for Ce6 to produce cytotoxic singlet oxygen (1O2), which significantly enhances the photodynamic therapy (PDT) efficiency. Moreover, CNTs could also be utilized as a photothermal agent for both photothermal imaging and therapy (PTT) to further improve the therapeutic efficacy. In addition, the photosensitizer Ce6 could also be used for in vitro and vivo fluorescence imaging. The results demonstrate that the smart tumor microenvironment responsive nanoplatform Ce6‐MnO2/CNTs with EPR effect and oxygen‐self‐generation property hold great potential in photothermal/fluorescence imaging guided synergistic PDT/PTT for cancer treatment in clinic.
Cobalt‐Copper Catalyzed C(sp2) – N Cross Coupling of Amides or Nitrogenated Heterocycles with Styrenyl or Aryl Halides
Authors: Ghosh Tubai , Maity Pintu , Ranu Brindaban C. 
Published: April 2018

AbstractAn efficient C(sp2) – N cross coupling of cyclic and acyclic amides with styrenyl/aryl/heteroaryl halides catalyzed by cobalt acetylacetonate in combination with copper(I) iodide, has been achieved. A library of diversely substituted cyclic and acyclic enamides have been obtained in high yields by this procedure. The reaction is stereoselective producing (E)–enamides from trans‐styrenyl halides and (Z)‐ products from cis‐halides. This procedure has been successfully employed for the coupling of other N‐heterocycles such as pyrazole, imidazole and triazole with aryl/styrenyl/heteroaryl halides to produce the corresponding N‐coupled products. A probable mechanism has been suggested.
Predicted Gas‐Phase and Liquid‐Phase Acidities of Carborane Carboxylic and Dicarboxylic Acids
Authors: Oliva‐Enrich Josep M. , Humbel Stephane , Santaballa J. Arturo , Alkorta Ibon , Notario Rafael , Dávalos Juan Z. , Canle‐L. Moisés , Bernhardt Eduard , Holub Josef , Hnyk Drahomír 
Published: April 2018

AbstractBy means of MP2 and DFT computations we predict gas‐phase acidities and liquid‐phase (MeCN) acidities of (di)carboxylic acids derived from icosahedral ortho, meta, and para‐carboranes. For comparative purpose, we include the benzoic and phthalic acids. Substitution of benzene by a carborane cage – cage effect – strikingly increases the gas‐phase acidity (lower GA) for the (di)carboxylic acids, being the ortho isomers always the most acidic, following the order ortho ≫ meta > para. The computed GA of the dicarboxylic acid derived from ortho‐carborane is far lower than sulphuric acid, due to an enhanced stabilization of the carboxylate through an intramolecular OHO bridge connection, also taking place in phthalic acid. The change of GA relative to ortho, meta and para positions of the carboxylic groups ‐ isomer effect ‐ is larger for carboranes. As regards to liquid‐phase (MeCN), the computations show that carborane (di)carboxylic acids also show a larger acidity (lower pKa) as compared to the phthalic acids and that the dicarboxylic ortho‐carborane is also a superacid in the liquid phase (MeCN), due to the OHO bridge connection in the carboxylate, as in the gas phase. Additional computations show how much of this isomeric effect is to be attributed to the electronic delocalization.
Structure‐Catalytic Activity in a Series of Push‐Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts
Authors: Hloušková Zuzana , Tydlitát Jiří , Kong Manman , Pytela Oldřich , Mikysek Tomáš , Klikar Milan , Almonasy Numan , Dvořák Miroslav , Jiang Zhiyong , Růžička Aleš , Bureš Filip 
Published: April 2018

AbstractA series of dicyanopyrazine and dicyanoimidazole derived push‐pull molecules have been prepared and further investigated as photoredox catalysts. The fundamental properties of the catalysts were studied by DSC, X‐ray analysis, absorption/emission spectra, and electrochemistry and were completed with the DFT results. The catalytic activity has been evaluated in visible light induced α‐functionalization of amines (cross‐dehydrogenative coupling and annulation reaction of tetrahydroisoquinolines). Thorough structure‐property‐catalytic activity relationships were elucidated. The developed series of tailored organic photoredox catalysts allows synthetic chemists to perform desired reactions under sustainable and mild conditions employing solely visible light as a source of energy.
Novel Br⋅⋅⋅π(Chelate) Interaction in a 1D Coordination Polymer Revealing Aromaticity
Authors: Dutta Basudeb , Pratik Saied Md , Jana Srikanta , Sinha Chittaranjan , Datta Ayan , Mir Mohammad Hedayetullah 
Published: April 2018

AbstractA one‐dimensional coordination polymer (1D CP) [Cu(nip)(4‐brpy)2] (1) containing 16‐member metal‐ligand chelate ring exhibits unprecedented Br⋅⋅⋅π(chelate) interaction. The nucleus‐independent chemical shifts (NICS) calculation reveals that the chelate ring has aromaticity and strong interaction energy (‐24.8 kcal/mol) which plays important role in molecular self‐assembly in the crystal structure.
Stabilized Pony‐Sized‐CuFe2O4/Carbon Nitride Porous Composites with Boosting Fenton‐like Oxidation Activity
Authors: Lu Kangchao , Yang Fu , Lin Wei , Zhou Shijian , Xi Tao , Song Changjian , Kong Yan 
Published: April 2018

AbstractIn this study, pony‐sized Copper ferrite (CuFe2O4) nanoparticles were directly obtained and synchronously stabilized on nanoporous carbon nitride (MCN) named as CuFe2O4‐MCN, which emerges interestingly as a magnetically‐recycling heterogeneous Fenton‐like catalyst. The Fourier Transform Infrared, X‐ray diffraction, N2 desorption, X‐ray photoelectron spectroscopy and transmission electron microscopy were seriatim used to characterize these synthesized functional catalysts. These present results demonstrated that CuFe2O4‐MCN afford appreciable physical textural characteristics including well‐defined porous structure, advisable surface area and pore volume. The interaction between CuFe2O4 and MCN and its induced improved dispersion of CuFe2O4 NPs on MCN could be confirmed through XPS, FT‐IR, and TEM evidences. Impressively, the resulted CuFe2O4‐MCN composites exhibited a three times’ catalytic activity (kobs, 0.076 min−1) than that (kobs, 0.026 min−1) of mechanical mixture CuFe2O4‐MCN(M) in 4‐chlorophenol(CP) degradation. CuFe2O4‐MCN porous composites was further evaluated in catalysis according to various controlled parameters, including catalyst loading, H2O2 concentration, catalyst dosage and pH of 4‐CP degradation. At last, the catalytic stability of CuFe2O4‐MCN composites was investigated via magnetic recycling and reusage in next catalytic test. After three successive experimental runs, the porous structure and catalytic activity of CuFe2O4‐MCN catalysts remained constant.
Structure‐Dependent Photochromic Iodoargentate Hybrids Based on Photolytic Mechanism
Authors: Wang Meidan , Hao Pengfei , Shen Junju , Fu Yunlong 
Published: April 2018

AbstractThree inorganic‐organic iodoargentate hybrids, {[MBI][AgI2]}n (1) (MBI+=N, N′‐dimethylbenzimidazolium), {[MPy][AgI2]}n (2) and {[MPy][Ag2I3]}n (3) (MPy+=N‐methylpyridinium) have been synthesized, which exhibit structure‐dependent photoresponse and unique photochromic behavior based on photolytic mechanism.
Large Photothermal Effect in Sub‐40 nm h‐BN Nanostructures Patterned Via High‐Resolution Ion Beam
Authors: López Josué J. , Ambrosio Antonio , Dai Siyuan , Huynh Chuong , Bell David C. , Lin Xiao , Rivera Nicholas , Huang Shengxi , Ma Qiong , Eyhusen Soeren , Kaminer Ido E. , Watanabe Kenji , Taniguchi Takashi , Kong Jing , Basov Dimitri N. , Jarillo‐Herrero Pablo , Soljačić Marin 
Published: April 2018

AbstractThe controlled nanoscale patterning of 2D materials is a promising approach for engineering the optoelectronic, thermal, and mechanical properties of these materials to achieve novel functionalities and devices. Herein, high‐resolution patterning of hexagonal boron nitride (h‐BN) is demonstrated via both helium and neon ion beams and an optimal dosage range for both ions that serve as a baseline for insulating 2D materials is identified. Through this nanofabrication approach, a grating with a 35 nm pitch, individual structure sizes down to 20 nm, and additional nanostructures created by patterning crystal step edges are demonstrated. Raman spectroscopy is used to study the defects induced by the ion beam patterning and is correlated to scanning probe microscopy. Photothermal and scanning near‐field optical microscopy measure the resulting near‐field absorption and scattering of the nanostructures. These measurements reveal a large photothermal expansion of nanostructured h‐BN that is dependent on the height to width aspect ratio of the nanostructures. This effect is attributed to the large anisotropy of the thermal expansion coefficients of h‐BN and the nanostructuring implemented. The photothermal expansion should be present in other van der Waals materials with large anisotropy and can lead to applications such as nanomechanical switches driven by light.
Developments in label‐free microfluidic methods for single‐cell analysis and sorting
Authors: Carey Thomas R. , Cotner Kristen L. , Li Brian , Sohn Lydia L. 
Published: April 2018

Advancements in microfluidic technologies have led to the development of many new tools for both the characterization and sorting of single cells without the need for exogenous labels. Label‐free microfluidics reduce the preparation time, reagents needed, and cost of conventional methods based on fluorescent or magnetic labels. Furthermore, these devices enable analysis of cell properties such as mechanical phenotype and dielectric parameters that cannot be characterized with traditional labels. Some of the most promising technologies for current and future development toward label‐free, single‐cell analysis and sorting include electronic sensors such as Coulter counters and electrical impedance cytometry; deformation analysis using optical traps and deformation cytometry; hydrodynamic sorting such as deterministic lateral displacement, inertial focusing, and microvortex trapping; and acoustic sorting using traveling or standing surface acoustic waves. These label‐free microfluidic methods have been used to screen, sort, and analyze cells for a wide range of biomedical and clinical applications, including cell cycle monitoring, rapid complete blood counts, cancer diagnosis, metastatic progression monitoring, HIV and parasite detection, circulating tumor cell isolation, and point‐of‐care diagnostics. Because of the versatility of label‐free methods for characterization and sorting, the low‐cost nature of microfluidics, and the rapid prototyping capabilities of modern microfabrication, we expect this class of technology to continue to be an area of high research interest going forward. New developments in this field will contribute to the ongoing paradigm shift in cell analysis and sorting technologies toward label‐free microfluidic devices, enabling new capabilities in biomedical research tools as well as clinical diagnostics.This article is categorized under:

Diagnostic Tools > Biosensing
Diagnostic Tools > Diagnostic Nanodevices
Measurement of Total Liver Volume Using the Energy Expenditure: A New Formula
Authors: Donadon Matteo , Mimmo Antonio , Costa Guido , Cimino Matteo , Viganò Luca , Palmisano Angela , Torzilli Guido 
Published: April 2018

AbstractBackgroundThe assessment of liver volume (LV) is important before surgical resection or transplantation to reduce the risk of hepatic insufficiency. LV is usually measured using computed tomography or with some formulas. The aim of this study was to develop a new dynamic formula to predict LV.MethodsUsing computed tomography, LV was calculated in 101 patients without liver disease. LV was correlated with patient metabolic status, calculated with the Harris–Benedict equation for basal energy expenditure (BEE). Activity energy expenditure (AEE) was also calculated. Using linear regression analysis, a new formula was derived and was compared with Heinmann’s, Urata’s, Emre’s, Vauthey’s, Yoshizumi’s, Yu’s, and Hashimoto’s formulas.ResultsA new basal formula was established: LV = (0.789 × BEE) + 272. It was found to be the most accurate (R2 = 0.39, p < 0.001). Heinmann’s, Emre’s, and Vauthey’s formulas tend to overestimate LV, while Urata’s, Yoshizumi’s, Yu’s, and Hashimoto’s formulas tend to underestimate LV. A new AEE formula was also established: LV = (0.789 × AEE) + 272.ConclusionsThese formulas give a dynamic perspective of LV, which may be influenced by the patient’s actual clinical status. Using these formulas, it is possible to estimate an increased value of LV, which may contribute to a reduction in the risk of postoperative hepatic insufficiency.