bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐Pot and Regioselective Gold‐Catalyzed Synthesis of 2‐Imidazolyl‐1‐pyrazolylbenzenes from 1‐Propargyl‐1H‐benzotriazoles, Alkynes and Nitriles through α‐Imino Gold(I) Carbene Complexes
Authors: González Jairo , Santamaría Javier , Suárez‐Sobrino Ángel L. , Ballesteros Alfredo 
Published: March 2016

AbstractA three‐component gold(I)‐catalyzed synthesis of 2‐imidazoyl‐1‐pyrazolylbenzenes from 1‐propargyl‐1H‐benzotriazoles is described here. Initially the benzotriazole derivative suffers an intramolecular 5‐endo‐dig cyclization to form a triazapentalene. This dipolar compound is able to perform an intermolecular and regioselective attack to a gold‐activated alkyne. After triazole breakage, the pyrazole ring and an α‐imino gold carbene complex are formed. Finally, the iminocarbene is captured by a nitrile to form an imidazole ring.magnified image
Outcomes of modified endoscopic Lothrop in aspirin‐exacerbated respiratory disease with nasal polyposis
Authors: Morrissey David K. , Bassiouni Ahmed , Psaltis Alkis J. , Naidoo Yuresh , Wormald Peter‐John 
Published: March 2016

BackgroundPatients with aspirin‐exacerbated respiratory disease (AERD) and chronic rhinosinusitis with nasal polyps (CRSwNP) are often reported to be recalcitrant to standard medical and surgical intervention. Failure rates of standard endoscopic sinus surgery in these patients are reported to be as high as 90%. We review the outcomes for our cohort of AERD patients undergoing endoscopic sinus surgery and endoscopic modified Lothrop procedure (EMLP).MethodsData was collected prospectively between January 2001 and December 2013. Information including demographics, asthma status, aspirin sensitivity, 22‐item Sino‐Nasal Outcome Test (SNOT‐22), Lund‐Mackay scores, and endoscopic ostium assessment were collected for up to 5 years. Minimum follow‐up was 6 months.ResultsA total of 31 AERD patients underwent complete sphenoethmoidectomy, maxillary antrostomy and EMLP during the study period with an average follow‐up of 36 months. Polyp recurrence was seen in a total of 18 patients (58%). Seven patients required revision EMLP following initial surgery demonstrating a failure rate of 22.5%. AERD patients had a statistically significant increased risk of both nasal polyps recurrence and need for revision surgery. Revision EMLP was needed due to recurrence of nasal polyps in 6 cases and frontal ostium stenosis in a single case. Time to revision EMLP was similar between the groups.ConclusionComplete sphenoethmoidectomy, maxillary antrostomy, and EMLP is successful in a significant majority of patients with AERD and CRSwNP. It is well tolerated with a low complication rate and facilitates successful ongoing medical management of the condition in patients with AERD.
Placebo‐controlled assessment of somnolence effect of cetirizine: a meta‐analysis
Authors: Du Qiong , Zhou Yingchun 
Published: March 2016

BackgroundIt has been found that the most common adverse reaction which occurs more frequently on cetirizine than on placebo is somnolence. However, the somnolence rate varied widely among different studies. The objective of this study was to assess the somnolence effect of cetirizine 10 mg daily compared to placebo in patients aged 6 years and older using meta‐analysis and explore the sources of heterogeneity among different studies.MethodsDatabases were searched for randomized controlled trials (RCTs) of cetirizine published before 2015. Overall risk differences (RDs) were determined by meta‐analyses of 13 trials using the DerSimonian and Laird (D&L) method based on fixed‐effects and random‐effect models, respectively. The Q statistic, H statistic, and I2were calculated for heterogeneity analysis. Subgroup analysis, Galbraith plot, sensitivity analysis, and meta‐regression were also performed to explore the sources of heterogeneity.ResultsVarious analyses showed that heterogeneity existed among the 13 trials and the placebo run‐in period was the cause of heterogeneity. For RCTs without and with placebo run‐in period, the overall RDs were 6.51% (95% CI, 4.47% to 8.56%) and 1.03% (95% CI, −0.13% to 2.19%), respectively, which indicated that the difference in somnolence rate between cetirizine 10 mg daily and placebo was not statistically significant for the subgroup with placebo run‐in.ConclusionThe meta‐analysis showed that the RDs between cetirizine 10 mg daily and placebo on somnolence rate were different for studies with and without a placebo run‐in period. The results for studies with a placebo run‐in period suggested that cetirizine 10 mg daily has no somnolence effect compared to placebo.
Clinical implications of mucosal remodeling from chronic rhinosinusitis
Authors: Do Timothy Q. , Barham Henry P. , Earls Peter , Sacks Raymond , Christensen Jenna M. , Rimmer Janet , Harvey Richard J. 
Published: March 2016

BackgroundPrognostic implications of mucosal remodeling in chronic rhinosinusitis (CRS) remain unclear. Remodeling of respiratory mucosa in asthma is associated with greater medication use and decreased function. This study investigates the implications of mucosal remodeling on long‐term clinical outcomes in patients with CRS.MethodsA case‐control study of adult patients with CRS undergoing endoscopic sinus surgery (ESS) was performed. Mucosal remodeling was defined by squamous metaplasia, subepithelial fibrosis, and/or basement membrane thickening. The presence of remodeling changes were assessed relative to clinical and treatment outcomes at a minimum of 12 months postoperatively. Clinical outcomes were assessed at baseline and 12 months using a Nasal Symptom Score (NSS) and 22‐item Sino‐Nasal Outcome Test (SNOT‐22). Treatment outcomes were assessed by oral corticosteroid usage (burst/continuous), topical corticosteroid irrigation frequency, and further surgical intervention.ResultsA total of 110 patients (48.73 ± 14.75 years, 48.2% female) were assessed. Significant improvements where seen for the entire population, in both NSS (2.64 ± 1.06 to 1.34 ± 1.08, p < 0.001) and SNOT‐22 (2.05 ± 0.96 to 1.06 ± 0.79, p < 0.001). Patients with remodeling (n = 88) were younger (47.2 ± 14.8 vs 54.7 ± 13.5 years, p = 0.03), but had similar symptom scores. Remodeling was seen in CRS with nasal polyposis (CRSwNP) (54.5%) and eosinophilic chronic rhinosinusitis (eCRS) (59.8%). Symptom improvement at 12 months was similar between remodeled and non‐remodeled groups (NSS: Δ1.34 ± 1.20 vs Δ1.12 ± 1.31, p = 0.395; SNOT‐22: Δ1.05 ± 0.91 vs Δ0.73 ± 0.95, p = 0.124); however, patients with remodeling had greater corticosteroid irrigation frequency (64.0% vs 31.6% daily use, Kendall's tau‐b p = 0.004).ConclusionEstablished mucosal remodeling predicts a greater reliance on topical therapies to reach similar clinical endpoints as those without remodeling.
Evaluation of bacterial transmission to the paranasal sinuses through sinus irrigation
Authors: Hauser Leah J. , Ir Diana , Kingdom Todd T. , Robertson Charles E. , Frank Daniel N. , Ramakrishnan Vijay R. 
Published: March 2016

BackgroundSaline nasal irrigation is effective in the treatment of sinonasal disorders, including chronic rhinosinusitis (CRS). Despite bacterial contamination in rinse bottles and reports of infections from contaminated irrigation water, tap water is still used by ∼50% of irrigation users, raising a potential public health concern. This study aimed to determine whether bacteria from the water supply used in sinus irrigations colonizes the paranasal sinuses.MethodsSamples were taken from the: (1) water used for irrigation, (2) faucet or container the water originated from, (3) rinse bottle, and (4) postoperative ethmoid cavity from 13 subjects with CRS. Microbiota were characterized using quantitative polymerase chain reaction (qPCR) and 16S ribosomal RNA (rRNA) gene sequencing. The Morisita‐Horn beta‐diversity index (M‐H) was used to assess similarity in microbiota between samples, and genomic analysis was performed to assess clonality of cultured bacteria.ResultsOf 13 subjects, 6 used distilled water, 6 used tap water, and 1 used well water in this institutional review board (IRB)‐approved observational study. Well‐water had markedly more bacteria than tap or distilled water. There was a trend toward tap having more bacteria than distilled water. The sinus samples were notably dissimilar to the bottle, faucet, and irrigant (M‐H 0.15, 0.09, and 0.18, respectively). There was no difference in postoperative microbiotas between distilled and tap water users.ConclusionThe current study suggests that irrigation plays little role in establishing the sinus microbiome. Although rinsing with tap water may never be formally recommended, these data are useful to counsel patients who prefer to do so in non‐endemic areas if the municipal water supply is appropriately treated.
Metall‐organische Gerüstverbindungen: Photokatalysatoren für Redoxreaktion und die Produktion von Solarbrennstoffen
Authors: Dhakshinamoorthy Amarajothi , Asiri Abdullah M. , Garcia Hermenegildo 
Published: March 2016

AbstractMetall‐organische Gerüste (MOFs) sind kristalline poröse Materialien, die aus bi‐ oder multipodalen organischen Linkern und Übergangsmetall‐Knoten aufgebaut sind. Manche MOFs zeigen hohe strukturelle Stabilität und flexible Zusammensetzungen. MOFs können aufgrund von Lichtabsorption durch die organische Komponente oder den Metalloxid‐Knoten photosensitiv sein. Die Photoanregung der Lichtabsorptionseinheiten generiert einen Ligand‐zu‐Metall‐Ladungstrennungszustand, der zu photokatalytischer Aktivität führen kann. In diesem Aufsatz diskutieren wir die Vorteile und Besonderheiten von MOFs im Zusammenhang mit der Photokatalyse. Wir besprechen geeignete Verfahren zur Bestimmung der photokatalytischen Aktivität von MOFs und zur Abscheidung von Kokatalysatoren. Insbesondere stellen wir Beispiele für die photokatalytische Aktivität von MOFs in der H2‐Entwicklung, der CO2‐Reduktion, der Photooxygierung und der Photoreduktion vor.
Der Tunneleffekt von Atomen in der Chemie
Authors: Meisner Jan , Kästner Johannes 
Published: March 2016

AbstractDer quantenmechanische Tunneleffekt von Atomen wird immer häufiger als wichtiger Aspekt in chemischen Reaktionen identifiziert. Experimentell kann man Atomtunneln nur indirekt nachweisen; beispielsweise durch temperaturunabhängige Reaktionsgeschwindigkeitskonstanten oder durch sehr große kinetische Isotopeneffekte. Im Gegensatz dazu können theoretische Methoden den Einfluss des Tunneleffekts auf die Reaktionsgeschwindigkeit direkt bestimmen. Der Tunneleffekt ändert beispielsweise Reaktionspfade und Verzweigungsverhältnisse, ermöglicht chemische Reaktionen in astrochemischer Umgebung, die thermisch nicht stattfinden, und beeinflusst auch biochemische Prozesse.
Firefly Luciferase Mutants Allow Substrate‐Selective Bioluminescence Imaging in the Mouse Brain
Authors: Adams Spencer T. , Mofford David M. , Reddy G. S. Kiran Kumar , Miller Stephen C. 
Published: March 2016

AbstractBioluminescence imaging is a powerful approach for visualizing specific events occurring inside live mice. Animals can be made to glow in response to the expression of a gene, the activity of an enzyme, or the growth of a tumor. But bioluminescence requires the interaction of a luciferase enzyme with a small‐molecule luciferin, and its scope has been limited by the mere handful of natural combinations. Herein, we show that mutants of firefly luciferase can discriminate between natural and synthetic substrates in the brains of live mice. When using adeno‐associated viral (AAV) vectors to express luciferases in the brain, we found that mutant luciferases that are inactive or weakly active with d‐luciferin can light up brightly when treated with the aminoluciferins CycLuc1 and CycLuc2 or their respective FAAH‐sensitive luciferin amides. Further development of selective luciferases promises to expand the power of bioluminescence and allow multiple events to be imaged in the same live animal.
Leichte Neucodierung von Selenocystein in der Natur
Authors: Mukai Takahito , Englert Markus , Tripp H. James , Miller Corwin , Ivanova Natalia N. , Rubin Edward M. , Kyrpides Nikos C. , Söll Dieter 
Published: March 2016

AbstractSelenocystein (Sec oder U) wird durch Neuzuordnung des Stopp‐Codons UGA durch einen Sec‐spezifischen Elongationsfaktor und eine charakteristische RNA‐Struktur codiert. Um mögliche Codonvariationen zu finden, analysierten wir 6.4 Billionen Basenpaare metagenomischer Daten sowie 24 903 mikrobielle Genome für tRNASec‐Spezies. UGA ist erwartungsgemäß das vorherrschende Codon für Sec, allerdings finden wir auch tRNASec‐Spezies, die die Stopp‐Codons UAG und UAA erkennen, sowie weitere zehn Sense‐Codons. Die Synthese von Selenoproteinen durch UAG in Geodermatophilus und Blastococcus sowie durch das Cys‐Codon UGA in Aeromonas salmonicida konnte durch metabolische Markierung mit 75Se oder Massenspektrometrie bestätigt werden. Weitere tRNASec‐Spezies mit verschiedenen Anticodons ermöglichten es Escherichia coli, die aktive Form des Selenoproteins Formiatdehydrogenase H zu synthetisieren. Der genetische Code ist damit bedeutend flexibler, als bisher angenommen.
Surface Coordination of Black Phosphorus for Robust Air and Water Stability
Authors: Zhao Yuetao , Wang Huaiyu , Huang Hao , Xiao Quanlan , Xu Yanhua , Guo Zhinan , Xie Hanhan , Shao Jundong , Sun Zhengbo , Han Weijia , Yu Xue‐Feng , Li Penghui , Chu Paul K. 
Published: March 2016

AbstractA titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP.
Milde und vollständige Spaltung eines Carbonylliganden innerhalb eines einkernigen Übergangsmetallkomplexes
Authors: Braunschweig Holger , Celik Mehmet Ali , Dewhurst Rian D. , Kachel Stephanie , Wennemann Benedikt 
Published: March 2016

AbstractWährend die vollständige Spaltung einer Kohlenstoff‐Sauerstoff‐Bindung an Metallen, zweikernigen Übergangsmetallkomplexen und Übergangsmetallclustern häufig beobachtet wird, ist diese Reaktion an einkernigen Übergangsmetallkomplexen bisher unbekannt. Die Reaktion eines Eisenbis(borylen)komplexes mit einem cyclischen (Alkyl)(amino)carben zeigte eine hochselektive intramolekulare Spaltung einer C‐O‐Bindung eines Carbonylliganden bei Raumtemperatur, was die Bildung eines ungewöhnlichen Eisenkomplexes mit basenstabilisiertem (Bora)alkylidenboranliganden zur Folge hatte. DFT‐Studien dieser Reaktion zeigen die Beteiligung der beiden Lewis‐aziden Borylenliganden an der Spaltung der C‐O‐Mehrfachbindung.
Copper/Guanidine‐Catalyzed Asymmetric Alkynylation of Isatins
Authors: Chen Quangang , Tang Yu , Huang Tianyu , Liu Xiaohua , Lin Lili , Feng Xiaoming 
Published: March 2016

AbstractThe highly enantioselective alkynylation of isatins, catalyzed by a bifunctional guanidine/CuI catalyst under mild reaction conditions, is described. The reaction is broad in scope with respect to alkyl/aryl‐substituted terminal alkynes and substituted isatins, thus affording bioactive propargylic alcohols in excellent yields and enantioselectivities.
Indium Oxide as a Superior Catalyst for Methanol Synthesis by CO2 Hydrogenation
Authors: Martin Oliver , Martín Antonio J. , Mondelli Cecilia , Mitchell Sharon , Segawa Takuya F. , Hauert Roland , Drouilly Charlotte , Curulla‐Ferré Daniel , Pérez‐Ramírez Javier 
Published: March 2016

AbstractMethanol synthesis by CO2 hydrogenation is attractive in view of avoiding the environmental implications associated with the production of the traditional syngas feedstock and mitigating global warming. However, there still is a lack of efficient catalysts for such alternative processes. Herein, we unveil the high activity, 100 % selectivity, and remarkable stability for 1000 h on stream of In2O3 supported on ZrO2 under industrially relevant conditions. This strongly contrasts to the benchmark Cu‐ZnO‐Al2O3 catalyst, which is unselective and experiences rapid deactivation. In‐depth characterization of the In2O3‐based materials points towards a mechanism rooted in the creation and annihilation of oxygen vacancies as active sites, whose amount can be modulated in situ by co‐feeding CO and boosted through electronic interactions with the zirconia carrier. These results constitute a promising basis for the design of a prospective technology for sustainable methanol production.
Palladium‐Catalyzed Carbonylative Four‐Component Synthesis of Thiochromenones: The Advantages of a Reagent Capsule
Authors: Shen Chaoren , Spannenberg Anke , Wu Xiao‐Feng 
Published: March 2016

AbstractMulticomponent reactions, especially those involving four or even more reagents, have been a long‐standing challenge because of the issues associated with balancing reactivity, selectivity, and compatibility. Herein, we demonstrate how the use of a reagent capsule provides straightforward access to synthetically valuable thiochromenone derivatives by a palladium‐catalyzed carbonylative four‐component reaction. To the best of our knowledge, this is the first example of applying a capsule to prevent catalyst poisoning and undesired side reactions of the multicomponent reaction.
Polyfunktionelle Lithium‐, Magnesium‐ und Zinkalkenyl‐Reagentien als Grundbausteine für die Synthese komplexer Heterocyclen
Authors: Shen Zhi‐Liang , Dhayalan Vasudevan , Benischke Andreas D. , Greiner Robert , Karaghiosoff Konstantin , Mayer Peter , Knochel Paul 
Published: March 2016

AbstractNeue konjunktive β‐silylierte organometallische Li‐, Mg‐ und Zn‐Reagentien wurden hergestellt und für den Aufbau einer Vielzahl von polyfunktionalisierten 5‐, 6‐ und 7‐gliedrigen Heterocyclen wie Furane, Pyrrole, Chinoline, Benzo[b]thieno[2,3‐b]pyridin, Naphthyridine, kondensierte Pyrazole und 2,3‐Dihydrobenzo[c]azepine verwendet. Die endständige Silylgruppe konnte in den meisten Heterocyclenklassen in neue Kohlenstoff‐Kohlenstoff‐Bindungen umgewandelt werden.
Controllable ROMP Tacticity by Harnessing the Fluxionality of Stereogenic‐at‐Ruthenium Complexes
Authors: Mikus Malte S. , Torker Sebastian , Hoveyda Amir H. 
Published: March 2016

AbstractReadily accessible and easy‐to‐handle Ru complexes capable of generating all‐Z polynorbornene and polynorbornadiene by ring‐opening metathesis polymerization (ROMP) with controllable selectivity, ranging from ≈50 to ≥95 % syndiotactic, are introduced. It is demonstrated that the rate of non‐metathesis based polytopal isomerization and levels of syndiotacticity may be fine‐tuned by the adjustment of monomer concentration and catalyst's steric and electronic characteristics.
Direct Asymmetric Reductive Amination for the Synthesis of Chiral β‐Arylamines
Authors: Huang Haizhou , Liu Xiaoyan , Zhou Le , Chang Mingxin , Zhang Xumu 
Published: March 2016

AbstractThe highly efficient and direct asymmetric reductive amination of arylacetones catalyzed by an iridium complex for the preparation of enantiomerically pure β‐arylamines is described. The monodentate phosphoramidite ligand exhibits superb reactivity (TONs of up to 20 000) and enantioselectivity (up to 99 % ee). Additives played important roles in this reductive coupling reaction.
Polymer Acceptor Based on B←N Units with Enhanced Electron Mobility for Efficient All‐Polymer Solar Cells
Authors: Zhao Ruyan , Dou Chuandong , Xie Zhiyuan , Liu Jun , Wang Lixiang 
Published: March 2016

AbstractWe demonstrate that polymer electron acceptors with excellent all‐polymer solar‐cell (all‐PSC) device performance can be developed from polymer electron donors by using B←N units. By alleviating the steric hindrance effect of the bulky pendant moieties on the conjugated polymers that contain B←N units, the π–π stacking distance of polymer backbones is decreased and the electron mobility is consequently enhanced by nearly two orders of magnitude. As a result, the power conversion efficiency of all‐PSCs with the polymer acting as the electron acceptor is greatly improved from 0.12 % to 5.04 %. This PCE value is comparable to that of the best all‐PSCs with state‐of‐the‐art polymer acceptors.
Atom Tunneling in Chemistry
Authors: Meisner Jan , Kästner Johannes 
Published: March 2016

AbstractQuantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom tunneling can be indirectly detected by temperature‐independent rate constants at low temperature or by enhanced kinetic isotope effects. In contrast, the influence of tunneling on the reaction rates can be monitored directly through computational investigations. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes.
Transition‐Metal Carbodiimides as Molecular Negative Electrode Materials for Lithium‐ and Sodium‐Ion Batteries with Excellent Cycling Properties
Authors: Sougrati Moulay T. , Darwiche Ali , Liu Xiaohiu , Mahmoud Abdelfattah , Hermann Raphael P. , Jouen Samuel , Monconduit Laure , Dronskowski Richard , Stievano Lorenzo 
Published: March 2016

AbstractWe report evidence for the electrochemical activity of transition‐metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as negative electrode material for alkali‐metal‐ion batteries, similar to its oxide analogue FeO. Based on 57Fe Mössbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe−NCN into Li/Na−NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well‐established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not require heavy treatments (such as nanoscale tailoring, sophisticated textures, or coating) to obtain long cycle life with current density as high as 9 A g−1 for hundreds of charge–discharge cycles. Similar to the iron compound, several other transition‐metal carbodiimides Mx(NCN)y with M=Mn, Cr, Zn can cycle successfully versus lithium and sodium. Their electrochemical activity and performance open the way to the design of a novel family of anode materials.
Atomic‐Scale Determination of Active Facets on the MoVTeNb Oxide M1 Phase and Their Intrinsic Catalytic Activity for Ethane Oxidative Dehydrogenation
Authors: Melzer Daniel , Xu Pinghong , Hartmann Daniela , Zhu Yuanyuan , Browning Nigel D. , Sanchez‐Sanchez Maricruz , Lercher Johannes A. 
Published: March 2016

AbstractAberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) has been used to image the basal {001} plane of the catalytically relevant M1 phase in MoVTeNb complex oxides. Facets {010}, {120}, and {210} are identified as the most frequent lateral termination planes of the crystals. Combination of STEM with He ion microscopy (HIM) images, Rietveld analysis, and kinetic tests reveals that the activation of ethane is correlated to the availability of facets {001}, {120}, and {210} at the surface of M1 crystals. The lateral facets {120} and {210} expose crystalline positions related to the typical active centers described for propane oxidation. Conversely, the low activity of the facet {010} is attributed to its configuration, consisting of only stable M6O21 units connected by a single octahedron. Thus, we quantitatively demonstrated that differences in catalytic activity among M1 samples of equal chemical composition depend primarily on the morphology of the particles, which determines the predominant terminating facets.