bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organocatalytic, Enantioselective Synthesis of Cyclohexadienone Containing Hindered Spirocyclic Ethers through an Oxidative Dearomatization/Oxa‐Michael Addition Sequence
Authors: Reddy Reddy Rajasekhar , Gudup Satish Sonbarao , Ghorai Prasanta 
Published: November 2016

AbstractAn unprecedented enantioselective oxa‐Michael reaction of α‐tertiary alcohols using cinchona‐alkaloid‐based chiral bifunctional squaramide catalysts is reported. An oxidative dearomatization of phenol followed by an enantioselective oxa‐Michael addition sequence provided a broad array of chiral sterically hindered tetrahydrofurans and tetrahydropyrans attached to a cyclohexadienone moiety in spiro fashion. In general, good yields and excellent enantioselectivities (up to 99 %) were observed. The chiral oxo‐cycles obtained have easily been transformed into chromans without disturbing the enantioselectivity.
Hollow Chevrel‐Phase NiMo3S4 for Hydrogen Evolution in Alkaline Electrolytes
Authors: Jiang Jun , Gao Minrui , Sheng Wenchao , Yan Yushan 
Published: November 2016

AbstractElectrochemical water splitting to generate molecular hydrogen requires catalysts that are cheap, active, and stable, particularly for alkaline electrolyzers, where the cathodic hydrogen evolution reaction is slower in base than in acid even on platinum. Herein, we describe the synthesis of new hollow Chevrel‐phase NiMo3S4 and its alkaline hydrogen evolution reaction (HER) performance: onset potential of −59 mV, Tafel slope of 98 mV per decade, and exchange current density of 3.9×10−2 mA cm−2. This Chevrel‐phase chalcogenide also demonstrates outstanding long‐term stability under harsh HER cycling conditions. Chevrel‐phase nanomaterials show promise as efficient, low‐cost catalysts for alkaline electrolyzers.
carbo‐Naphthalene: A Polycyclic carbo‐Benzenoid Fragment of α‐Graphyne
Authors: Cocq Kévin , Saffon‐Merceron Nathalie , Coppel Yannick , Poidevin Corentin , Maraval Valérie , Chauvin Remi 
Published: November 2016

AbstractA ring carbo‐mer of naphthalene, C32Ar8 (Ar=p‐n‐pentylphenyl), has been obtained as a stable blue chromophore, after a 19‐step synthetic route involving methods inspired from those used in the synthesis of carbo‐benzenes, or specifically devised for the present target, like a double Sonogashira‐type coupling reaction. The last step is a SnCl2/HCl‐mediated reduction of a decaoxy‐carbo‐decalin, which is prepared through successive [8+10] macrocyclization steps. Two carbo‐benzene references are also described, C18Ar6 and o‐C18Ar4(C≡C‐SiiPr3)2. The carbo‐naphthalene bicycle is locally aromatic according to structural and magnetic criteria, as revealed by strong diatropic ring current effects on the deshielding of 1H nuclei of the Ar groups and on the negative value of the DFT‐calculated NICS at the center of the C18 rings (−12.8 ppm). The stability and aromaticity of this smallest fused molecular fragment of α‐graphyne allows prediction of the same properties for the carbon allotrope itself.
Excited Fluorophores Enhance the Opening of Vesicles at Electrode Surfaces in Vesicle Electrochemical Cytometry
Authors: Najafinobar Neda , Lovrić Jelena , Majdi Soodabeh , Dunevall Johan , Cans Ann‐Sofie , Ewing Andrew 
Published: November 2016

AbstractElectrochemical cytometry is a method developed recently to determine the content of an individual cell vesicle. The mechanism of vesicle rupture at the electrode surface involves the formation of a pore at the interface between a vesicle and the electrode through electroporation, which leads to the release and oxidation of the vesicle's chemical cargo. We have manipulated the membrane properties using excited fluorophores conjugated to lipids, which appears to make the membrane more susceptible to electroporation. We propose that by having excited fluorophores in close contact with the membrane, membrane lipids (and perhaps proteins) are oxidized upon production of reactive oxygen species, which then leads to changes in membrane properties and the formation of water defects. This is supported by experiments in which the fluorophores were placed on the lipid tail instead of the headgroup, which leads to a more rapid onset of vesicle opening. Additionally, application of DMSO to the vesicles, which increases the membrane area per lipid, and decreasing the membrane thickness result in the same enhancement in vesicle opening, which confirms the mechanism of vesicle opening with excited fluorophores in the membrane. Light‐induced manipulation of membrane vesicle pore opening might be an attractive means of controlling cell activity and exocytosis. Additionally, our data confirm that in experiments in which cells or vesicle membranes are labeled for fluorescence monitoring, the properties of the excited membrane change substantially.
A Bis(silylenyl)pyridine Zero‐Valent Germanium Complex and Its Remarkable Reactivity
Authors: Zhou Yu‐Peng , Karni Miriam , Yao Shenglai , Apeloig Yitzhak , Driess Matthias 
Published: November 2016

AbstractThe synthesis, reactivity, and electronic structure of the unique germylone iron carbonyl complex [SiNSi]Ge0→Fe(CO)4 is reported. The compound was obtained in 49 % yield from the reaction of the bis(N‐heterocyclic silylenyl)pyridine pincer ligand SiNSi (1,6‐C5NH3‐[EtNSi(NtBu)2CPh]2) with GeCl2⋅(dioxane) to give the corresponding chlorogermyliumylidene chloride precursor [SiNSi]GeIICl+ Cl−, which was further reduced with K2Fe(CO)4. Single‐crystal X‐ray diffraction analysis of [SiNSi]Ge→Fe(CO)4 revealed that the Ge0 center adopts a trigonal‐pyramidal geometry with a Si‐Ge‐Si angle of 95.66(2)°. Remarkably, one of the SiII donor atoms in the complex is five‐coordinated because of additional (pyridine)N→Si coordination. Unexpectedly, the reaction of [SiNSi]Ge→Fe(CO)4 with GeCl2⋅(dioxane) (one molar equivalent) yielded the first push–pull germylone–germylene donor–acceptor complex, [SiNSi]Ge→GeCl2→Fe(CO)4 through the insertion of GeCl2 into the dative Ge0→Fe bond. The electronic features of the new compounds were investigated by DFT calculations.
A Nernstian Biosupercapacitor
Authors: Pankratov Dmitry , Conzuelo Felipe , Pinyou Piyanut , Alsaoub Sabine , Schuhmann Wolfgang , Shleev Sergey 
Published: November 2016

AbstractWe propose the very first “Nernstian biosupercapacitor”, a biodevice based on only one redox polymer: poly(vinyl imidazole‐co‐allylamine)[Os(bpy)2Cl], and two biocatalysts. At the bioanode PQQ‐dependent glucose dehydrogenase reduces the Os3+ moieties at the polymer to Os2+ shifting the Nernst potential of the Os3+/Os2+ redox couple to negative values. Concomitantly, at the biocathode the reduction of O2 by means of bilirubin oxidase embedded in the same redox polymer leads to the oxidation of Os2+ to Os3+ shifting the Nernst potential to higher values. Despite the use of just one redox polymer an open circuit voltage of more than 0.45 V was obtained during charging and the charge is stored in the redox polymer at both the bioanode and the biocathode. By connecting both electrodes via a predefined resistor a high power density is obtained for a short time exceeding the steady state power of a corresponding biofuel cell by a factor of 8.
Polystyrene Sulfonate Threaded through a Metal–Organic Framework Membrane for Fast and Selective Lithium‐Ion Separation
Authors: Guo Yi , Ying Yulong , Mao Yiyin , Peng Xinsheng , Chen Banglin 
Published: November 2016

AbstractExtraction of lithium ions from salt‐lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST‐1 metal–organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST‐1‐6.7, with unique anchored three‐dimensional sulfonate networks, shows a very high Li+ conductivity of 5.53×10−4 S cm−1 at 25 °C, 1.89×10−3 S cm−1 at 70 °C, and Li+ flux of 6.75 mol m−2 h−1, which are five orders higher than that of the pristine HKUST‐1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li+, Na+, K+, and Mg2+ ions to the sulfonate groups, the PSS@HKUST‐1‐6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li+/Na+, Li+/K+, Li+/Mg2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li+ extraction membranes.
Contrasting Magnetic Behaviors in Rhodium‐ and Ruthenium‐Doped Cubic Perovskite SrFeO3: Nearly Ferromagnetic Metal versus Spin‐Glass Insulator
Authors: Kinoshita Masataka , Sakai Hideaki , Hayashi Naoaki , Tokura Yoshinori , Takano Mikio , Ishiwata Shintaro 
Published: November 2016

AbstractThe effects of Rh and Ru doping for SrFeO3, a helimagnetic metal with a cubic perovskite structure, are studied by magnetic and resistivity measurements. Although SrRhO3 is a paramagnetic metal and SrRuO3 is a ferromagnetic one, the Rh doping induces a nearly ferromagnetic metallic state, whereas the Ru doping induces a spin‐glass insulating state. Mössbauer measurements evidence a marked difference between SrFe0.8Rh0.2O3 and SrFe0.8Ru0.2O3 in the formal valences of Fe, which are estimated to be 4+ and 3.75+, respectively. The contrasting magnetic behaviors of Rh‐ and Ru‐doped SrFeO3 are discussed in terms of the subtle balance between the double‐exchange ferromagnetism and the superexchange antiferromagnetism.
Debugging Eukaryotic Genetic Code Expansion for Site‐Specific Click‐PAINT Super‐Resolution Microscopy
Authors: Nikić Ivana , Estrada Girona Gemma , Kang Jun Hee , Paci Giulia , Mikhaleva Sofya , Koehler Christine , Shymanska Nataliia V. , Ventura Santos Camilla , Spitz Daniel , Lemke Edward A. 
Published: November 2016

AbstractSuper‐resolution microscopy (SRM) greatly benefits from the ability to install small photostable fluorescent labels into proteins. Genetic code expansion (GCE) technology addresses this demand, allowing the introduction of small labeling sites, in the form of uniquely reactive noncanonical amino acids (ncAAs), at any residue in a target protein. However, low incorporation efficiency of ncAAs and high background fluorescence limit its current SRM applications. Redirecting the subcellular localization of the pyrrolysine‐based GCE system for click chemistry, combined with DNA‐PAINT microscopy, enables the visualization of even low‐abundance proteins inside mammalian cells. This approach links a versatile, biocompatible, and potentially unbleachable labeling method with residue‐specific precision. Moreover, our reengineered GCE system eliminates untargeted background fluorescence and substantially boosts the expression yield, which is of general interest for enhanced protein engineering in eukaryotes using GCE.
Indenylmetal Catalysis in Organic Synthesis
Authors: Trost Barry M. , Ryan Michael C. 
Published: November 2016

AbstractSynthetic organic chemists have a long‐standing appreciation for transition metal cyclopentadienyl complexes, of which many have been used as catalysts for organic transformations. Much less well known are the contributions of the benzo‐fused relative of the cyclopentadienyl ligand, the indenyl ligand, whose unique properties have in many cases imparted differential reactivity in catalytic processes toward the synthesis of small molecules. In this Review, we present examples of indenylmetal complexes in catalysis and compare their reactivity to their cyclopentadienyl analogues, wherever possible.
Spectroscopic andin silicostudy of binding mechanism of cynidine‐3‐O‐glucoside with human serum albumin and glycated human serum albumin
Authors: Gao Xin , Bi Hongna , Jia Jingjing , Tang Lin 
Published: November 2016

AbstractThe drug–serum albumin interaction plays a dominant role in drug efficacy and disposition. The glycation of serum albumin that occurs during diabetes may affect its drug‐binding propertiesin vivo. In order to evaluate the interactivity characteristics of cyanidin‐3‐O‐glucoside (C3G) with human serum albumin (HSA) and glycated human serum albumin (gHSA), this study was undertaken using multiple spectroscopic techniques and molecular modeling analysis. Time‐resolved fluorescence and the thermodynamic parameters indicated that the quenching mechanism was static quenching, and hydrogen bonding and Van der Waals force were the main forces. The protein fluorescence could be quenched by C3G, whereas the polarity of the fluorophore was not obviously changed. C3G significantly altered the secondary structure of the proteins. Furthermore, the interaction force that existed in the HSA–C3G system was greater than that in the gHSA–C3G system. Fluorescence excitation emission matrix spectra, red edge excitation shift, Fourier transform infrared spectroscopy and circular dichroism spectra provided further evidence that glycation could inhibit the binding between C3G and proteins. In addition, molecular modeling analysis supported the experimental results. The results provided more details for the application of C3G in the treatment of diabetes.
Dendrimeric Guanidinoneomycin for Cellular Delivery of Bio‐macromolecules
Authors: Sganappa Aurora , Wexselblatt Ezequiel , Bellucci Maria Cristina , Esko Jeffrey D. , Tedeschi Gabriella , Tor Yitzhak , Volonterio Alessandro 
Published: November 2016

AbstractWe present the synthesis of polymeric amino‐ and guanidinoglycosides prepared by tethering neomycin and guanidinoneomycin to PAMAM dendrimers of generations 2 and 4. The ability of these conjugates to promote cellular uptake of high‐molecular‐weight cargo is discussed, together with their cytotoxicity and mechanisms of entry. We demonstrate that the presence of multiple guanidinoneomycin carriers on the PAMAM surface plays an important role in promoting cellular uptake of the dendrimers, maintaining the heparan sulfate specificity and negligible cytotoxicity typical of monomeric guanidinoglycoside molecular transporters.
Activation of Chlorinated Methanes at the Surface of Nanoscopic Lewis Acidic Aluminum Fluorides
Authors: Siwek Agnieszka K. , Ahrens Mike , Feist Michael , Braun Thomas , Kemnitz Erhard 
Published: November 2016

AbstractWe report on the activation of chlorinated methanes by the heterogeneous catalysts aluminum chlorofluoride (ACF) and high‐surface aluminum fluoride (HS‐AlF3) under moderate conditions. For comparison, chlorinated toluenes and 1,2‐dichloroethane were also tested. The strong Lewis acids are able to promote the cleavage of C−Cl bonds in the presence of Et3SiH. The C−Cl bonds were converted into C−H bonds through hydrodechlorination reactions or, in the presence of benzene, into C−C bonds through Friedel–Crafts type reactions. The catalytic reactions show high conversions.
Defect Engineering, Electronic Structure, and Catalytic Properties of Perovskite Oxide La0.5Sr0.5CoO3−δ
Authors: Wang Xiyang , Huang Keke , Ma Wei , Cong Yingge , Ge Chengda , Feng Shouhua 
Published: November 2016

AbstractThe electronic structures of transition metal oxides play a crucial role in the physical and chemical properties of solid materials. Defect engineering is an efficient way to regulate the electronic structure and improve the performance of materials. Here, we develop a defect engineering route that is implemented by controlling the topochemical reactions between cobalt perovskite and urea to optimize the electronic structure of La0.5Sr0.5CoO3−δ (LSCO). Urea pyrolysis is able to increase the oxygen defect concentration and cause octahedral distortions. Furthermore, we can distinctly observe that the introduction of oxygen vacancies narrows the hybridization orbital between O 2p and Co 3d and optimizes the O p‐band center near the Fermi level by X‐ray absorption spectroscopy, which greatly improves the catalytic activity of CO oxidation and photocatalytic water splitting. These results highlight the relationship between oxygen defects, electronic structure, and catalytic activity of perovskite LSCO, and demonstrate a rational approach to defect design and reveal the importance of anion redox chemistry for the structures and properties of perovskite oxides.
Copper‐Catalyzed Remote para‐C−H Functionalization of Anilines with Sodium and Lithium Sulfinates
Authors: Liang Shuai , Bolte Michael , Manolikakes Georg 
Published: November 2016

AbstractA copper‐catalyzed, cross‐dehydrogenative coupling of anilines with sodium and lithium sulfinates was developed. By using a cooperative reaction system with Mn(OAc)3 as stoichiometric co‐oxidant a highly selective para‐functionalization of anilines was accomplished. Various functional groups were tolerated and the desired products were obtained in high yields. This method not only provides a novel approach for the synthesis of arylsulfones but might also offer new opportunities for the development of copper‐catalyzed para‐selective C−H functionalizations.
Exercise test predictors of severe coronary artery disease: Role of ST‐segment elevation in lead aVR
Authors: Russo Giulio , Ravenna Salvatore Emanuele , De Vita Antonio , Aurigemma Cristina , Lamendola Priscilla , Lanza Gaetano Antonio , Crea Filippo 
Published: November 2016

BackgroundThe role of exercise stress test (EST)‐induced ST‐segment elevation (STE) in electrocardiographic lead aVR in predicting severe coronary artery disease (CAD) is controversial.HypothesisAssessment of lead aVR during EST can be helpful to identify patients with severe CAD.MethodsWe performed maximal EST in 200 patients undergoing coronary angiography for suspect of CAD. Four angiographic findings of severe CAD were considered: (1) left main (LM) disease; (2) LM or equivalent LM (LM/EQLM) disease; (3) LM or proximal left anterior descending (LAD) artery (LM/proxLAD) disease; and (4) LM or 3‐vessel (LM/3V) disease.Results
LM, LM/EQLM, LM/proxLAD, and LM/3V disease were shown in 6 (3%), 13 (6.5%), 33 (16.5%), and 27 (13.5%) patients, respectively. EST‐induced STE in aVR occurred in 41 patients (20.5%). ST‐segment depression (STD) in ≥5 leads was the only predictor of LM stenosis (odds ratio [OR]: 6.18, 95% confidence interval [CI]: 1.19‐32.2, P = 0.03) and the most significant variable associated with LM/proxLAD stenosis (OR: 4.73, 95% CI: 2.0‐11.2, P = 0.0001); maximal STD ≥3 mm was the most significant variable associated with LM/EQLM (OR: 7.58, 95% CI: 2.31‐24.9, P = 0.001) and LM/3V (OR: 3.86, 95% CI: 1.47‐10.1, P = 0.006) CAD. EST‐induced STE in aVR was associated with LM/proxLAD disease only (OR: 3.23, 95% CI: 1.44‐7.24, P = 0.004). At multivariate analysis, STD in ≥5 leads was the only independent predictor of LM/proxLAD disease (OR: 3.99, 95% CI: 1.58‐10.1, P = 0.003).Conclusions
EST‐induced STE in lead aVR does not significantly increase the prediction of severe CAD compared with severity and extension of STD as assessed in the other electrocardiographic leads.
Notch3 expression correlates with thyroid cancer differentiation, induces apoptosis, and predicts disease prognosis
Authors: Somnay Yash R. , Yu Xiao‐Min , Lloyd Ricardo V. , Leverson Glen , Aburjania Zviadi , Jang Samuel , Jaskula‐Sztul Renata , Chen Herbert 
Published: November 2016

BACKGROUNDThyroid tumorigenesis is characterized by a progressive loss of differentiation exhibited by a range of disease variants. The Notch receptor family (1‐4) regulates developmental progression in both normal and cancerous tissues. This study sought to characterize the third Notch isoform (Notch3) across the various differentiated states of thyroid cancer, and determine its clinical impact.METHODSNotch3 expression was analyzed in a tissue microarray of normal and pathologic thyroid biopsies from 155 patients. The functional role of Notch3 was then investigated by upregulating its expression in a follicular thyroid cancer (FTC) cell line.RESULTSNotch3 expression regressed across decreasingly differentiated, increasingly malignant thyroid specimens, correlated with clinicopathological attributes reflecting poor prognosis, and independently predicted survival following univariate and multivariate analyses. Overexpression of the active Notch3 intracellular domain (NICD3) in a gain‐of‐function FTC line led to functional activation of centromere‐binding protein 1, while increasing thyroid‐specific gene transcription. NICD3 induction also reduced tumor burden in vivo and initiated the intrinsic apoptotic cascade, alongside suppressing cyclin and B‐cell lymphoma 2 family expression.CONCLUSIONSLoss of Notch3 expression may be fundamental to the process of dedifferentiation that accompanies thyroid oncogenesis. Conversely, activation of Notch3 in thyroid cancer exerts an antiproliferative effect and restores elements of a differentiated phenotype. These findings provide preclinical rationale for evaluating Notch3 as a disease prognosticator and therapeutic target in advanced thyroid cancer. Cancer 2017;123:769–82. © 2016 American Cancer Society.
Assessment of the treatment approach and survival outcomes in a modern cohort of patients with atypical teratoid rhabdoid tumors using the National Cancer Database
Authors: Fischer‐Valuck Benjamin W. , Chen Ishita , Srivastava Amar J. , Floberg John M. , Rao Yuan James , King Allison A. , Shinohara Eric T. , Perkins Stephanie M. 
Published: November 2016

BACKGROUNDAtypical teratoid rhabdoid tumors (ATRTs) are rare brain tumors that occur primarily in children under the age of 3 years. This report evaluates the treatment approach and survival outcomes in a large cohort of patients treated in the United States.METHODSUsing the National Cancer Database, the analysis included all ATRT patients aged 0 to 18 years who were diagnosed between 2004 and 2012 and had complete treatment data.RESULTSThree hundred sixty‐one ATRT patients were evaluated. The 5‐year overall survival (OS) rate was 29.9%, and it was significantly lower for children who were less than 3 years old (5‐year OS, 27.7%) versus those who were 3 years old or older (5‐year OS, 37.5%; P < .001). The best outcome was seen for patients with localized disease who received trimodality therapy (surgery, chemotherapy, and radiation therapy [RT]) with a 5‐year OS rate of 46.8%. The utilization of trimodality therapy significantly increased during the study period (27.7% in 2004‐2008 vs 45.1% in 2009‐2012; P < .01), largely because of the increased use of RT. In a multivariate analysis, treatment that did not utilize trimodality therapy was associated with significantly worse OS (hazard ratio, 2.52; 95% confidence interval (1.82–3.51). Children aged 0 to 2 years were significantly less likely to receive trimodality therapy because of decreased utilization of RT in this age group.CONCLUSIONSThe use of trimodality therapy significantly increased during the study period and was associated with improved outcomes. For patients with localized disease who received trimodality therapy, the OS rate at 5 years approached 50%. However, further research into the optimal management of children less than 3 years old is needed because of their significantly worse OS in comparison with older children. Cancer 2017;123:682–687. © 2016 American Cancer Society.