bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Single Route to Mammalian N‐Glycans Substituted with Core Fucose and Bisecting GlcNAc
Authors: Luber Thomas , Niemietz Mathäus , Karagiannis Theodoros , Mönnich Manuel , Ott Dimitri , Perkams Lukas , Walcher Janika , Berger Lukas , Pischl Matthias , Weishaupt Markus , Eller Steffen , Hoffman Joanna , Unverzagt Carlo 
Published: August 2018

AbstractThe occurrence of α1,6‐linked core fucose on the N‐glycans of mammalian glycoproteins is involved in tumor progression and reduces the bioactivity of antibodies in antibody‐dependent cell‐mediated cytotoxicity (ADCC). Since core‐fucosylated N‐glycans are difficult to isolate from natural sources, only chemical or enzymatic synthesis can provide the desired compounds for biological studies. A general drawback of chemical α‐fucosylation is that the chemical assembly of α1,6‐linked fucosides is not stereospecific. A robust and general method for the α‐selective fucosylation of acceptors with primary hydroxy groups in α/β ratios exceeding 99:1 was developed. The high selectivities result from the interplay of an optimized protecting group pattern of the fucosyl donors in combination with the activation principle and the reaction conditions. Selective deprotection yielded versatile azides of all mammalian complex‐type core‐fucosylated N‐glycans with 2‐4 antennae and optional bisecting GlcNAc.
Synthesis of 1,3‐Amino Alcohols by Hydroxy‐Directed Aziridination and Aziridine Hydrosilylation
Authors: Zhang Yong‐Qiang , Bohle Fabian , Bleith Robin , Schnakenburg Gregor , Grimme Stefan , Gansäuer Andreas 
Published: August 2018

AbstractWe describe an approach to N‐tosyl 1,3‐amino alcohols that consists of a diastereoselective aziridination reaction of acyclic allylic alcohols and an unprecedented regioselective hydrosilylation of α‐hydroxy aziridines. The products contain up to three contiguous stereocenters. Computational studies outline key aspects of the aziridination mechanism, which is different and more intricate than anticipated.
Expanding the Genetic Code to Study Protein–Protein Interactions
Authors: Nguyen Tuan‐Anh , Cigler Marko , Lang Kathrin 
Published: August 2018

AbstractProtein–protein interactions are central to many biological processes. A considerable challenge consists however in understanding and deciphering when and how proteins interact, and this can be particularly difficult when interactions are weak and transient. The site‐specific incorporation of unnatural amino acids (UAAs) that crosslink with nearby molecules in response to light provides a powerful tool for mapping transient protein–protein interactions and for defining the structure and topology of protein complexes both in vitro and in vivo. Complementary strategies consist in site‐specific incorporation of UAAs bearing electrophilic moieties that react with natural nucleophilic amino acids in a proximity‐dependent manner, thereby chemically stabilizing low‐affinity interactions and providing additional constraints on distances and geometries in protein complexes. Herein, we review how UAAs bearing fine‐tuned chemical moieties that react with proteins in their vicinity can be utilized to map, study, and characterize weak and transient protein–protein interactions in living systems.
Pyrene‐Containing Twistarene: Twelve Benzene Rings Fused in a Row
Authors: Chen Wangqiao , Li Xinxiong , Long Guankui , Li Yongxin , Ganguly Rakesh , Zhang Mingtao , Aratani Naoki , Yamada Hiroko , Liu Ming , Zhang Qichun 
Published: August 2018

AbstractSuccess in obtaining higher‐order twistarenes with precise structures is very important for fundamentally understanding the relationship between the structures and physical properties/optoelectronic applications. In this research, by using the advantages from a retro‐Diels–Alder process (clean reaction) and the cross‐conjugated nature of the pyrene unit, a novel dodeca‐twistarene was prepared for the first time. Its structure, confirmed by single‐crystal XRD analysis, indicates that it possesses a twisted angle (≈30°), and two neighboring molecules in the crystal lattice are perpendicular to each other because of the twisted character and the strong intermolecular CH–π interactions. However, its basic physicochemical properties suggest its instability in air derives from its elevated HOMO energy level, although NICS calculations confirm that the pyrene units contribution poorly to the π conjugation of the overall molecule.
Dual functional novel catalytic Cu1−xZrxFe2O4 (x=0, 0.5, 1) nanoparticles for synthesis of polysubstituted pyridines and sunlight‐driven degradation of methylene blue
Authors: Singh Harminder , Rajput Jaspreet Kaur , Govil Garima , Arora Priya , Badhan Jigyasa 
Published: August 2018

The effect of varied zirconium content on the structural, morphological, magnetic, optical, thermal and catalytic properties of nanoparticles of the ferrite Cu1 − xZrxFe2O4 (x = 0, 0.5, 1) was investigated. The mixed ferrite was synthesized by the auto‐combustion method using nitrates of respective metals and citric acid as a chelating agent. The as‐prepared nanoparticles showed dual benefits. They were employed as a heterogeneous catalyst for one‐pot synthesis of polysubstituted pyridine derivatives as well as for catalytic degradation of industrial waste dyes such as methylene blue (MB). The highlight of the research reported is the catalytic degradation of industrial waste (MB) with high efficiency in eluent of a wide range of pH (3–13). The proposed nanoparticles arguably offer certain great advantages that include: low cost, facile nature, anti‐leaching property, magnetic recoverability and recyclability. The characterization of the as‐synthesized nanoparticles was done using various techniques. The leaching study was carried out using inductively coupled plasma optical emission spectroscopy. The formation of organic products was confirmed using Fourier transform infrared and 1H NMR spectroscopies and examination of degradation products of MB dye was carried out using mass spectrometry and UV–visible spectroscopy.
Enhanced positive temperature coefficient in amorphous PS/CSPE‐MWCNT composites with low percolation threshold
Authors: Lai Fang , Wang Bin‐Bin , Zhang Peng 
Published: August 2018

ABSTRACTIn this work, amorphous polystyrene/chlorosulfonated polyethylene composites doped with multiwalled carbon nanotubes (PS/CSPE‐MWCNT) were constructed by in situ polymerization to form semi‐interpenetrating networks. The MWCNTs showed excellent dispersion and selective location in the PS regions. High electrical conductivity and low percolation threshold (0.89 wt %) for the composites were achieved. An enhanced positive temperature coefficient (PTC) behavior for amorphous PS/CSPE‐MWCNT composites was first reported, nearly without a negative temperature coefficient (NTC) effect when the conductive fillers were beyond the percolation threshold, similar to those of crystalline polymer composites. Moreover, a PTC intensity of more than five orders of magnitude and excellent repeatability of the PTC effect were achieved. This study offers new insight into the development of novel PTC materials with low percolation threshold. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47053.
The mechanism of the preventive effect of Shen’an capsule on the calcium oxalate crystal‐induced early renal injury based on metabolomics
Authors: Fan Wei , Hou Jiebin , Zhu Weiye , Zhang Shuyue , Shao Keda , Quan Feiyu , Chen Wei 
Published: August 2018

AbstractKidney stone disease is a worldwide metabolism‐associated disorder with a high incidence of renal dysfunction. However, effective methods to prevent crystalline nephropathy are still lacking owing to the absence of aetiological research. Shen’an (SA) capsules are prepared from Chinese medicinal compounds and are considered a promising treatment for the prevention of crystal‐induced renal injury. In this study, 24 mice were randomly divided into four groups: saline, oxalate, SA‐treated (via preventive administration) and SA‐only groups. A metabolomics analysis based on ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UPLC‐Q‐TOF/MS) was performed to explore the plasma metabolic profiles among the different groups. The amount of crystal deposition and the decline in kidney function were significantly alleviated by the use of SA capsule. A total of 24 metabolites that showed a reversal trend following SA capsule administration were identified as plasma biomarkerss of the preventive effects of SA capsules on crystal‐induced renal injury. Most of these metabolites were involved in the metabolisms of lipid metabolism, energy metabolism, glutathione metabolism and vitamin metabolism. In conclusion, SA capsules exert a preventive effect in mice with crystal‐induced kidney injury via the regulation of multiple metabolic pathways.
Radiological characteristics and predisposing factors of venous tumor thrombus in pelvic osteosarcoma: A mono‐institutional retrospective study of 115 cases
Authors: Liang Haijie , Guo Wei , Yang Rongli , Tang Xiaodong , Yan Taiqiang , Ji Tao , Yang Yi , Li Dasen , Xie Lu , Xu Jie 
Published: August 2018

AbstractBackgroundVenous tumor thrombus (VTT) in pelvic osteosarcoma has been regarded as a rare oncological condition and few literatures investigated this issue.MethodsWe retrospectively reviewed 115 cases of pelvic osteosarcoma treated in our center from 2006 to 2016. Diagnosis of VTTs was made based on histo‐pathological findings. We summarized the radiological manifestations of VTTs on CT, MRI, and PET/CT. We also compared the demographical, oncological, and radiological data between cases with or without VTTs to identify its predisposing factors.ResultsSeventeen cases (14.8%) were diagnosed with VTT. Manifestations of VTTs on CT included increased caliber (64.7%), calcification (47.1%), low density on plain scan (100%), filling defect (100%), and streak‐like enhancement (35.7%) on contrast enhancement. On MRI, the VTTs could be hypo‐ or iso‐intense on T1WI (100%), hyperintense on T2WI (100%), and filling defect on contrast enhancement (100%). PET/CT showed high metabolic activity of the VTTs. The ranges of the VTTs included unilateral external iliac vein (EIV) (two cases), unilateral internal iliac vein (IIV) (one case), unilateral common iliac vein (CIV) and IIV (five cases), unilateral CIV + EIV (two cases), inferior vena cava (IVC) and unilateral CIV + EIV (one case), IVC and unilateral CIV + IIV (four cases), IVC and bilateral CIVs + IIVs (two cases). Multivariate analysis indicated that chondroblastic subtype and involvement of L5/S1 intervertebral foramen might predispose to VTTs.ConclusionThe incidence of VTTs in pelvic osteosarcoma was 14.8%. Comprehensive radiological studies help preoperative diagnosis of VTTs. Predisposing factors included chondroblasic subtype and involvement of L5/S1 intervertebral foramen.
Sulfated Iron Oxide‐Catalyzed Esterification of Acetic Acid with n‐Butanol by Reactive Distillation
Authors: Kaur Jaspreet , Kaur Kamalpreet , Toor Amrit Pal 
Published: August 2018

AbstractThe potential applicability of reactive distillation was investigated in the esterification of acetic acid with n‐butanol catalyzed by sulfated iron oxide at a stoichiometric molar ratio. Low‐cost, easily available, and reusable uncoated clay beads were used as column packing. Higher acid conversion in a shorter reaction time was achieved in the reactive distillation process in comparison to the batch process. The effects of reaction temperature, catalyst loading, packing material, and packing height on acid conversion were investigated. The Eley‐Rideal model was found to be appropriate to elaborate the reaction kinetics and resulted in a lower activation energy for the reactive distillation process compared with the batch process.
Removal of NO from Flue Gas by a Heterogeneous Fenton‐Like Process
Authors: Zhao Yi , Han Yuhong , Zhao Zheng 
Published: August 2018

AbstractAn iron‐containing polyoxometalates (POMs) complex (FeIIIAspPW) was synthesized from ferric chloride, aspartic acid, and phosphotungstic acid for developing a novel method based on a Fenton‐like process using Fe‐containing POMs as heterogeneous catalyst to remove NO from flue gas. The effects of various experimental parameters on NO removal efficiency were evaluated in a self‐made bubbling reactor. Under optimized conditions, an average removal efficiency of > 90 % was obtained. The dominant reactive species generated in the system was suggested to be •OH by adding the •OH quenching agent of tert‐butanol and the main reaction product was identified as nitrate. A possible catalytic mechanism was proposed on the basis of experimental results and references. The catalysis might result from the redox cycles of ≡FeIII↔≡FeII and ≡POM↔≡POM− on the surface of FeIIIAspPW, and the high catalytic activity of FeIIIAspPW might be attributed to the chemisorption of H2O2 on its surface by hydrogen bonding.
Methodological Evaluation of Storage Systems for Flexible Power Generation from Solid Biomass
Authors: Stark Matthias , Trinkl Christoph , Zörner Wilfried , Greenough Rick 
Published: August 2018

AbstractThe increasing number of fluctuating renewable power producers in the electricity grid leads to several challenges in the grid's infrastructure and its operation. Biomass combustion plants, however, can be modified to increase the flexibility of power production by integrating steam storage devices. In this paper, the available storage systems are evaluated, considering the boundaries of the plants and the requirements of power grids and markets. An objective result is generated by conducting a Delphi study using energy experts. The utility‐value‐analysis method is used to identify the most promising storage concept. Using this methodology, the resulting storage concept is found to be a combination of a steam accumulator and a solid storage.
Reactive Zinc Extraction with D2EHPA in a Kühni Miniplant Column
Authors: Korb Christian , Keller Alexander , Bart Hans-Jörg 
Published: August 2018

AbstractReactive extraction of Zn2+ with di‐(2‐ethylhexyl) phosphoric acid (D2EHPA) was examined in a multistage countercurrent extraction column of type Kühni. Hydrodynamics and mass transfer for the reactive European Federation of Chemical Engineering (EFCE) test system were comprehensively experimentally investigated in a DN32 Kühni miniplant column. The experiments demonstrate that the column hydrodynamics and mass transfer performance markedly depend on throughputs, phase ratio, energy input as well as on the component concentrations. Using a simple equilibrium stage model, it was found that two to four stages per meter can be reached in the miniplant extractor. The system physical properties (density, viscosity, interfacial tension) of the reactive test system change rapidly due to mass transfer, which is considered by appropriate correlations.
Single‐Step Anodization for the Formation of WO3‐Doped TiO2 Nanotubes Toward Enhanced Electrochromic Performance
Authors: Yoo Hyeonseok , Oh Kiseok , Nah Yoon‐Chae , Choi Jinsub , Lee Kiyoung 
Published: August 2018

AbstractHerein, we report a single‐step anodization process for WO3‐doped TiO2 nanotubes in an aqueous electrolyte containing the tungsten precursor Na2WO4 ⋅ 2H2O and fluoride ions. The single‐step anodization allows for homogeneous doping of WO3 into the TiO2 nanotube structures. The doping concentration depends on the concentration of the tungsten precursor in the electrolyte, demonstrating that the reported anodizing process is the most efficient approach for metal oxide doping in TiO2. Moreover, compared to bare TiO2, the WO3‐doped TiO2 nanotubes shows better proton intercalation, which leads to enhanced electrochromic performance.
SVM for FT‐MIR prostate cancer classification: An alternative to the traditional methods
Authors: Siqueira Laurinda F.S. , Morais Camilo L.M. , Araújo Júnior Raimundo F. , de Araújo Aurigena Antunes , Lima Kássio M.G. 
Published: August 2018

AbstractIn this paper, principal component analysis (PCA), successive projections algorithm (SPA), and genetic algorithm (GA) followed by support vector machines (SVM), combined with Fourier‐transform mid‐infrared (FT‐MIR) spectroscopy were presented as complementary or alternatives tools to the traditional methods for prostate cancer screening and classification. These approaches were applied to analyze tissue samples, and their performances were compared within dependent SVM models and with traditional methods of diagnosis, according to class separation interpretability, time consumption, and figures of merit. The results showed that variable reduction and selection methods followed by SVM can reduce drawbacks of independent SVM analysis. The potential biomarkers indicated by PCA‐SVM, SPA‐SVM, and GA‐SVM were amide I, II, and III; as well as protein regions (1400‐1585 cm−1), followed by DNA/RNA (O—P—O symmetric stretch) (1080 cm−1) and DNA (O—P—O asymmetric stretch) (1230 cm−1) regions. GA‐SVM was the best classification approach, with higher sensitivity (100%) and specificity (80%), particularly in early stages, being better than traditional methods of diagnosis.
Distinct Effects of O‐GlcNAcylation and Phosphorylation of a Tau‐Derived Amyloid Peptide on Aggregation of the Native Peptide
Authors: Frenkel‐Pinter Moran , Richman Michal , Belostozky Anna , Abu‐Mokh Amjaad , Gazit Ehud , Rahimipour Shai , Segal Daniel 
Published: August 2018

AbstractProtein phosphorylation and O‐GlcNAcylation are very common nucleoplasmic post‐translational modifications. Mono‐addition of either the phosphate or the O‐GlcNAc group were shown to inhibit the self‐aggregation of amyloidogenic proteins and peptides, which is the hallmark of various protein misfolding diseases. However, their comparable effect upon co‐incubation with a native non‐modified amyloid scaffold has not been reported. O‐linked glycans and phosphate variants of the tau protein‐derived VQIVYK hexapeptide motif were generated as a simplified amyloid scaffold model and demonstrate that, while self‐aggregation can be attenuated by either a single glycan or a phosphate unit, only co‐incubation with the O‐GlcNAc variant inhibits aggregation of the native peptide. These results shed light on the role of post‐translational modifications in protein aggregation and suggest a novel therapeutic approach to protein misfolding diseases.
Indenoquinaldine‐Based Unsymmetrical Squaraine Dyes for Near‐Infrared Absorption: Investigating the Steric and Electronic Effects in Dye‐Sensitized Solar Cells
Authors: Bisht Rajesh , Mele Kavungathodi Munavvar Fairoos , Nithyanandhan Jayaraj 
Published: August 2018

AbstractA series of near‐infrared (NIR)‐responsive unsymmetrical squaraine dyes (ISQ1–3) incorporating a fused indenoquinaldine‐based donor have been designed and synthesized. C12 alkyl chains were incorporated at the sp3‐hybridized carbon center of the indene unit of the indenoquinaldine in an out‐of‐plane orientation to control dye aggregation on the surface of titanium dioxide, and indole (ISQ1), benzo[e]indole (ISQ2), and quinoline (ISQ3) moieties were included as the donor component bearing the anchoring carboxy group to extend the absorption in the NIR region and to systematically study the effect of the electronic modification on the performance of dye‐sensitized solar cells (DSSC). All the dyes exhibit intense absorption (ϵ≥105 m−1 cm−1) in the NIR region, and the dye‐adsorbed TiO2 films exhibit broad panchromatic absorption. The incident photon‐to‐current efficiency (IPCE) spectrum of the ISQ3‐based DSSC device displays a panchromatic IPCE response up to 880 nm. Additionally, the ISQ3‐sensitized device provides the best efficiency of 4.15 % with a short circuit current density (JSC) of 10.02 mA cm−2, open‐circuit voltage (VOC) of 0.58 V, and fill factor (ff) of 72 % in the presence of 10 equivalents of 3α,7α‐dihydroxy‐5β‐cholanic acid (CDCA). Electrochemical impedance spectroscopy analysis showed attenuated charge recombination in the ISQ3‐sensitized DSSC, which contributes to its higher value of VOC compared with the other dyes.
High‐Yield Generation of Triplet Excited States by an Efficient Sequential Photoinduced Process from Energy Transfer to Singlet Fission in Pentacene‐Modified CdSe/ZnS Quantum Dots
Authors: Sakai Hayato , Inaya Ryutaro , Tkachenko Nikolai V. , Hasobe Taku 
Published: August 2018

AbstractSinglet fission (SF) is expected to improve photoenergy conversion systems by generating two electrons from one photon. Pentacenes meet the energy‐level matching condition between a singlet and two triplet states: [E(S1)≥2E(T1)]. However, the molar absorption coefficients of pentacenes in the approximately 400–500 nm region are limited, whereas quantum dots, such as CdSe/ZnS (QD), possess high fluorescence quantum yields and particle‐size‐dependent fluorescence wavelengths. Thus, a combination of QD (D) and pentacene (A) provides a system of both an enhanced light‐harvesting efficiency throughout the solar spectrum and an efficient conversion of the harvested light into the triplet states by SF. Based on these points, m‐phenylene‐bridged triisopropylsilane (TIPS)‐pentacene dimer‐functionalized QD (denoted as m‐(Pc)2‐QD) was synthesized to examine the sequential photoinduced process from energy transfer to SF. In femtosecond transient absorption measurements, initial energy transfer from QD to pentacene (quantum yield: 87 %) and subsequent SF were efficiently observed. The quantum yield of triplet states of pentacene units (ΦΤ) based on the excitation of QD attained is 160±6.7 %.
HN2O2− as a Ligand in Mononuclear Hydrogenhyponitrite‐κ2‐N,O Ruthenium Complexes with Bisphosphane Co‐Ligands
Authors: Beck Daniel , Klüfers Peter 
Published: August 2018

AbstractThe hyponitrite anion is a tentative intermediate in the reduction of nitric oxide (NO) to nitrous oxide (N2O) catalyzed by nitric‐oxide reductase (NOR) in the process of bacterial denitrification. Owing to the considerable number of known coordination modes for the hyponitrito ligand, its actual bonding form in the enzymatic cycle is a point of current discussion. Here, we contribute to the hardly known ligand properties of a key intermediate, the monoprotonated hyponitrite anion. Three air‐ and water‐stable ruthenium complexes with hydrogenhyponitrite as the ligand were synthesized by using commercially available bisphosphane co‐ligands (1,2‐bis(diphenylphosphino)ethane (dppe), 1,3‐bis(diphenylphosphino)propane (dppp), 1,2‐bis(diphenylphosphino)ethene (dppv)). The starting compounds [Ru(dppe)2(tos)]BF4 (1) and [Ru(dppp)2(tos)]BF4 (2) contained the bidentate coordinating tosylate anion (tos) as a particularly well‐suited leaving group. To confirm the protonated and deprotonated species, X‐ray diffraction, IR, UV/Vis spectroscopy (solution and solid state), solid‐state NMR spectroscopy, and high‐resolution mass spectroscopy were used. DFT calculations give insight into the bonding situation. We report on [Ru(dppe)2(HN2O2)]BF4 (5), [Ru(dppp)2(HN2O2)]BF4 (6), [Ru(dppv)2(HN2O2)]BF4 (7), [Ru(dppp)2(HN2O2)]BF4⋅Imi (9; Imi=imidazole) as the first mononuclear trans‐hydrogenhyponitrite complexes. Isolated deprotonated analogs are [Ru(dppe)2(N2O2)]⋅HImi(BF4) (8) and [Ru(dppv)2(N2O2)] ⋅HImi(BF4)⋅Imi (10).