bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: A Catalytic Asymmetric Isatin‐Involved Povarov Reaction: Diastereo‐ and Enantioselective Construction of Spiro[indolin‐3,2′‐quinoline] Scaffold.
Authors: Shi Feng , Xing Gui‐Juan , Zhu Ren‐Yi , Tan Wei , Tu Shujiang 
Published: April 2013

AbstractThe presented first catalytic asymmetric Povarov reaction directly assembles isatins, anilines, and styrenes into new enantioenriched title compounds with concomitant creation of two quaternary stereogenic centers in high yields and excellent stereoselectivities.
ChemInform Abstract: Enantioselective Cooperative Triple Catalysis: Unique Roles of Au(I)/Amine/Chiral Broensted Acid Catalysts in the Addition/Cycloisomerization/Transfer Hydrogenation Cascade.
Authors: Patil Nitin T. , Raut Vivek S. , Tella Ramesh Babu 
Published: April 2013

AbstractAn enantioselective, cooperative process involving the concerted action of three different catalysts is realized for the synthesis of 2‐substituted tetrahydroquinolines (III) from 2‐aminobenzaldehydes (I) and alkynes (II).
ChemInform Abstract: Synthesis and Antioxidant Activities of 2‐Oxo‐quinoline‐3‐carbaldehyde Schiff‐Base Derivatives.
Authors: Zhang Ye , Fang Yilin , Liang Hong , Wang Hengshan , Hu Kun , Liu Xianxian , Yi Xianghui , Peng Yan 
Published: April 2013

AbstractTitle compounds [(III) and (IV)] are synthesized and shown to have good in vitro antioxidant activities compared with commercial antioxidants ascorbic acid, BHT and BHA.
ChemInform Abstract: Synthesis of N‐Alkyl and N‐Aryl Isoquinolones and Derivatives via Pd‐Catalyzed C—H Activation and Cyclization Reactions.
Authors: Zhang Nana , Li Binyao , Zhong Hongban , Huang Jianhui 
Published: April 2013

AbstractThe reaction tolerates various substitutions on the aromatic ring of benzamides and is applicable to the heteroaromatic amides.
ChemInform Abstract: Study of the Synthesis of Some Biginelli‐Type Products Catalyzed by Nano‐ZrO2.
Authors: Farhadi Asadollah , Takassi Mohammad Ali , Hejazi Leila 
Published: April 2013

AbstractA simple and efficient method for the synthesis of a variety of 4‐substituted dihydropyrimidinone derivatives (IV) (18 examples) is developed using the three‐component coupling of various aromatic aldehydes, β‐diketones, and urea under mild and environmentally friendly reaction conditions.
ChemInform Abstract: Asymmetric Rhodium‐Directed anti‐Markovnikov Regioselective Boracyclopentannulation.
Authors: Toure Momar , Chuzel Oliver , Parrain Jean‐Luc 
Published: April 2013

AbstractTreatment of boranes of type (I) and (III) bearing a terminal or disubstituted olefin with catalytic amounts of [Rh(nbd)2]BF4 and the chiral phosphine (S)‐(POS) is found to allow a new, highly regio‐ and stereoselective method to boracyclopentane derivatives like (II) and (IV).
ChemInform Abstract: Anomalous Reactivity of Silylborane: Transition‐Metal‐Free Boryl Substitution of Aryl, Alkenyl, and Alkyl Halides with Silylborane/Alkoxy Base Systems.
Authors: Yamamoto Eiji , Izumi Kiyotaka , Horita Yuko , Ito Hajime 
Published: April 2013

AbstractThe synthesized boron‐compounds can be used as substrates for Suzuki‐Miyaura coupling reactions as demonstrated by the authors.
ChemInform Abstract: Iron‐Catalyzed Diastereoselective Synthesis of α‐(Methoxycarbonyl)allylsilanes.
Authors: Chai Guobi , Zeng Rong , Fu Chunling , Ma Shengming 
Published: April 2013

AbstractThis reaction gives the title compounds (III) from easily available allenes and Grignard reagents in good yields.
ChemInform Abstract: Gold‐Catalyzed Sequential Alkyne Activation for the Synthesis of 4,6‐Disubstituted Phosphorus 2‐Pyrones.
Authors: Mo Juntae , Kang Dongjin , Eom Dahan , Kim Sung Hong , Lee Phil Ho 
Published: April 2013

AbstractOne‐ or two‐step reaction procedures are presented for the preparation of phosphorus‐2‐pyrones (III).
ChemInform Abstract: Metallic Chalcogenolates Mediated Modular Michael‐Aldol Cascade Reaction: An Easy Route to Multi‐Functionalized Chalcogenides and Morita—Baylis—Hillman Adducts.
Authors: Sousa Bruno A. , Keppler Arthur F. , Gariani Rogerio A. , Comasseto Joao V. , Dos Santos Alcindo A. 
Published: April 2013

AbstractTreatment of metallic chalcogenolates generated in situ with aldehydes and various activated alkenes or alkynes allows an efficient and fast access to a number of γ‐hydroxychalcogenides.
ChemInform Abstract: A General and Green Procedure for the Synthesis of Organochalcogenides by CuFe2O4 Nanoparticle Catalyzed Coupling of Organoboronic Acids and Dichalcogenides in PEG‐400.
Authors: Kundu Debasish , Mukherjee Nirmalya , Ranu Brindaban C. 
Published: April 2013

AbstractThe catalyst is magnetically separable and recyclable eight times without any significant loss of catalytic activity.
ChemInform Abstract: Catalytic Diastereo‐ and Enantioselective Annulations Between Transient Nitrosoalkenes and Indoles.
Authors: Zhang Yu , Stephens David , Hernandez Graciela , Mendoza Rosalinda , Larionov Oleg V. 
Published: April 2013

AbstractFor the first time a highly enantioselective catalytic [4+2] annulation of unstable and extremely reactive in situ prepared nitrosoalkenes is developed by using the synergistic combination of copper catalyst and a silver base.
ChemInform Abstract: Venezuelines A—G, New Phenoxazine‐Based Alkaloids and Aminophenols from Streptomyces venezuelae and the Regulation of Gene Target Nur77.
Authors: Ren Jinwei , Liu Dong , Tian Li , Wei Yangye , Proksch Peter , Zeng Jinzhang , Lin Wenhan 
Published: April 2013

AbstractVenezuelines (I)‐(IV) are isolated from the fermentation broth of title bacterium.
ChemInform Abstract: Organic Synthesis via Magnetic Attraction: Benign and Sustainable Protocols Using Magnetic Nanoferrites.
Authors: Baig R. B.Nasir , Varma Rajender S. 
Published: April 2013

AbstractThis is a complete summary of recently published studies on the utilization of glutathion‐ and DOPA‐based magnetically separable catalysts in organic synthesis.
ChemInform Abstract: 3‐Substituted Prolines: From Synthesis to Structural Applications, from Peptides to Foldamers
Authors: Mothes Celine , Caumes Cecile , Guez Alexandre , Boullet Heloise , Gendrineau Thomas , Darses Sylvain , Delsuc Nicolas , Moumne Roba , Oswald Benoit , Lequin Olivier , et al. et al. 
Published: April 2013

AbstractReview: 78 refs.
ChemInform Abstract: Synthesis of Dichloroindium Hydride and Exploration of Its Reactivity with Organic Functional Groups. Tandem, Selective and Partial Reductions of Halo‐nitriles
Authors: Saavedra Jaime Z. , Bayrasy Panathda , Resendez Angel , Snelling Rachel , Anderson Michael H. , Singaram Bakthan 
Published: April 2013

AbstractReview: 50 refs.
Influence of Loading Rate on the Deformation and Fracture Behavior of Wheat Grains
Authors: Omarov Azamat , Müller Peter , Tomas Jürgen 
Published: April 2013

AbstractIn der vorliegenden Arbeit werden Ergebnisse der experimentellen Untersuchungen des Deformations‐ und Bruchverhaltens von Weizenkörnern bei verschiedenen Druckbeanspruchungen vorgestellt. Die Beanspruchungsgeschwindigkeiten lagen zwischen 0,02 und 0,11 mm s–1. Die Anwendbarkeit des Kontaktmodells des sphärischen Partikels wurde für elliptische Weizenkörner bestätigt. Die wesentlichen Kennwerte der Brucheigenschaften von Weizenkörnern wie Bruchkraft, Bruchfestigkeit, Bruchenergie, Bruchweg wurden mit Normalverteilungen beschrieben.
Numerical Solutions of Population Balance Equations within Liquid/Gas‐Liquid Flow Simulations
Authors: Bayraktar Evren , Mierka Otto , Turek Stefan 
Published: April 2013

AbstractNumerical solvers based on population balance equations (PBE) coupled with flow equations are a promising approach to simulate liquid/gas‐liquid dispersed flows, which are very commonly observed in nature and in industrial processes. The challenges for the numerical solution of the coupled equation systems are discussed and detailed numerical recipes are presented whose main ingredients are the method of classes, positivity‐preserving linearization and the high‐order FEM‐AFC schemes, additional to the FeatFlow in‐house flow solver package. Liquid‐liquid flows through static mixers and dispersed phase systems in a flat bubble column are studied with the accordingly developed computational tool. The suggested recipes were validated by comparing the numerical results against experimental data.
Degree of polarization detection: a dual‐polarized antenna based spectrum sensing algorithm for cognitive radio
Authors: Lin Lin , Guo Caili , Feng Chunyan 
Published: April 2013

SUMMARYA new spectrum sensing algorithm‐degree of polarization (DoP) sensing algorithm is proposed in this paper. By exploiting a pair of dual‐polarized antenna at the receiver, DoP of the received vector signal is estimated and utilized to detect the presence of primary users based on the polarization characteristics of electromagnetic waves. The dual‐polarized narrowband and broadband systems are both considered for DoP detection. In theoretical analysis, we derive the probability of detection, the probability of false and detection threshold of the proposed algorithm. It is shown that our algorithm overcomes the noise uncertainty problem. Considering the polarization‐sensitive channel impairments, the impact of polarization mode dispersion on DoP detector is discussed. This method can be utilized for various signal detection applications without requiring the knowledge of signal, transmission channel, and noise power. In simulations based on wireless microphone signals, by applying polarization information signal carries, DoP achieves a better detection performance than arithmetic‐to‐geometric mean detector, the maximum‐to‐minimum ratio eigenvalue detector, and energy detector with noise uncertainty. The simulations based on digital video broadcasting‐terrestrial signals are also presented, which may show the detection performance of the proposed method may be affected by polarization mode dispersion. Copyright © 2013 John Wiley & Sons, Ltd.
Thymus‐homing dendritic cells in central tolerance
Authors: Hadeiba Husein , Butcher Eugene C. 
Published: April 2013

Central tolerance is critical in establishing a peripheral T‐cell repertoire purged of functional autoreactive T cells. One of the major requirements for effective central tolerance is the presentation of self and other innocuous antigens (Ags), including food, gut flora, or airway allergens, to developing T cells in the thymus. This seemingly challenging task can be mediated in some cases by ectopic expression of tissue‐specific Ags by thymic epithelial cells or by entry of systemic blood‐borne Ags into the thymus. More recently, thymic homing peripheral dendritic cells (DCs) have been proposed as cellular transporters of peripheral tissue‐specific Ags or foreign innocuous Ags. The aim of this viewpoint is to discuss the three principal thymic DC populations and their trafficking properties in the context of central tolerance. We will first discuss the importance of peripheral DC trafficking to the thymus and then compare and contrast the three DC subsets. We will describe how they were characterized, describe their trafficking to and their microenvironmental positioning in the thymus, and discuss the functional consequence of thymic trafficking and localization on thymic selection events.
Photochemical C–C Bond Formation between Alcohols and Olefins by an Environmentally Benign Radical Reaction
Authors: Ouchi Akihiko , Liu Chuanxiang , Kaneda Masayuki , Hyugano Takeshi 
Published: April 2013

AbstractA radical C–C bond formation between olefins and alcohols proceeded efficiently by simple light irradiation at room temperature. The reaction proceeded in the presence of commercially available tBuOOtBu without using the harmful elements and/or compounds that have an unpleasant smell that are often used in conventional radical reactions. In addition, the reaction did not require photosensitizers or photocatalysts, which eliminated the time‐consuming separation of sensitizers after the reaction, or the synthesis of photocatalysts as reported in previous procedures.
Synthesis and Characterization of 9‐(Fluoren­‐2‐yl)anthracene Derivatives as Efficient Non‐Doped Blue Emitters for Organic Light‐Emitting Diodes
Authors: Prachumrak Narid , Namuangruk Supawadee , Keawin Tinnagon , Jungsuttingwong Siriporn , Sudyoadsuk Taweesak , Promarak Vinich 
Published: April 2013

AbstractA series of 9‐(fluoren‐2‐yl)anthracene derivatives bearing either thiophene (FATh), triphenylamine (FAT and FATT) or pyrene (FATP) moieties as substituents have been designed, synthesized, and characterized as non‐doped blue emitters for organic light‐emitting diodes (OLEDs). Their optical, electrochemical and thermal properties have been investigated, and their molecular structure‐property relationships were evaluated. All FAT, FATT and FATP compounds possess combined blue‐light‐emitting and hole‐transporting characteristics, and showed stable amorphous states with high fluorescence quantum yields in solution (up to 89 %) and strong luminance in the OLED devices, whereas FATh showed poor photoluminescent and electroluminescent properties. Efficient, non‐doped blue and Alq3‐based green OLEDs were fabricated and characterized. The blue and green devices with maximum luminance efficiencies and CIE coordinates of 3.17 cd A–1 and (0.13, 0.14), and 3.81 cd A–1 and (0.28, 0.50) were achieved, respectively, with FATT having 4‐{bis[4′‐(diphenylamino)biphenyl‐4‐yl]amino}phenyl substituents as emitting layer and hole‐transporting layer, respectively. These devices also showed considerably low turn‐on voltages of 3.0 and 2.6 V, respectively.
Attribution of observed sea level pressure trends to greenhouse gas, aerosol, and ozone changes
Authors: Gillett Nathan P. , Fyfe John C. , Parker David E. 
Published: April 2013

AbstractHuman influence on atmospheric sea level pressure (SLP) has previously been detected globally, but the contributions of greenhouse gas, aerosol, and ozone changes to the observed trends have not been separately identified. We use simulations from eight climate models to show that greenhouse gas, aerosol, and ozone changes each drive distinct seasonal and geographical patterns of trends, which are separately detectable in observed seasonal SLP trends over the 1951–2011 period. This detection is driven by significant low‐latitude SLP responses to greenhouse gas, aerosol, and ozone changes, as well as the more frequently‐studied high latitude responses. These results aid in understanding past atmospheric circulation changes, and have potential to improve projections of future circulation changes.
Paleofire reconstruction based on an ensemble‐member strategy applied to sedimentary charcoal
Authors: Blarquez Olivier , Girardin Martin P. , Leys Bérangère , Ali Adam A. , Aleman Julie C. , Bergeron Yves , Carcaillet Christopher 
Published: April 2013

AbstractPaleofire events obtained from the statistical treatment of sedimentary charcoal records rely on a number of assumptions and user's choices, increasing the uncertainty of reconstructio\ns. Among the assumptions made when analyzing charcoal series is the choice of a filtering method for raw Charcoal Accumulation Rate (CHARraw). As there is no ultimate CHARraw filtering method, we propose an ensemble‐member approach to reconstruct fire events. We modified the commonly used procedure by including a routine replicating the analysis of a charcoal record using custom smoothing parameters. Dates of robust fire events, uncertainties in fire‐return intervals and fire frequencies are derived from members' distributions. An application of the method is used to quantify uncertainties due to data treatment in two CHARraw sequences from two different biomes, subalpine and boreal.
Intraoral nerve sheath myxoma: Case report and systematic review of the literature
Authors: Rozza‐de‐Menezes Rafaela Elvira , Andrade Raquel Machado , Israel Mônica Simões , Gonçalves Cunha Karin Soares 
Published: April 2013

AbstractBackgroundOral nerve sheath myxoma (NSM) is an uncommon benign neoplasm with Schwann‐cell origin, which is frequently mistaken for neurothekeoma. We report a case of NSM on the buccal mucosa in a 42‐year‐old woman. This case is compared with previously reported cases and a systematic review is performed.Methods and ResultsWe conducted a case report and systematic review of oral cases considered true NSMs. A literature search was performed using PubMed, Lilacs, Scielo, Cochrane, SciVerse Scopus, Web of Science, and Embase electronic database. Twenty‐five cases of oral NSM were included in the systematic review.ConclusionOral NSM is rare and may represent a diagnostic challenge for pathologists. To confirm the diagnosis of NSM, the evaluation of S‐100 protein expression or other neural marker is essential. The use of the terms NSM and neurothekeoma as synonymous or as variants of the same tumor should be avoided, because they are clearly distinct lesions. © 2013 Wiley Periodicals, Inc. Head Neck 35: E397–E404, 2013
Healthcare reform in Italy: an analysis of efficiency based on nonparametric methods
Authors: De Nicola Arianna , Gitto Simone , Mancuso Paolo , Valdmanis Vivian 
Published: April 2013

SUMMARYOver the past twenty years, important changes in the Italian health system have led to different approaches in organizing, delivering and financing health services throughout the country's regions. In this paper, we assess the impacts that such changes have had on health efficiency. The analysis performed here is in two stages. In the first stage, healthcare efficiency is measured via bootstrapped Data Envelopment Analysis. In the second stage, the impacts of organizational and environmental variables on efficiency are investigated. Our results highlight that the organizational model adopted by the Lombardia region allows for the best results in healthcare efficiency in Italy. A process of administrative decentralization from the regional governments to local health units appears to be a source of inefficiency. Finally, patient mobility has a significant impact on healthcare efficiency. Copyright © 2013 John Wiley & Sons, Ltd.
Effects of obliquity and water vapor/trace gas greenhouses in the early martian climate
Authors: Mischna Michael A. , Baker Victor , Milliken Ralph , Richardson Mark , Lee Christopher 
Published: April 2013

AbstractWe explore possible mechanisms for the generation of warm, wet climates on early Mars as a result of greenhouse warming by both water vapor and periodic volcanic trace emissions. The presence of both water vapor (a strong greenhouse gas) and other trace greenhouse gases (such as SO2) in a predominantly CO2atmosphere may act, under certain conditions, to elevate surface temperatures above the freezing point of liquid water, at least episodically. Variations in obliquity are explored to investigate whether these periodic variations in insolation at Mars can broaden the regions or seasons where warm temperatures can exist. We use the Mars Weather Research and Forecasting general circulation model to perform several simulations of the conditions of the early martian atmosphere containing these gases and find global temperatures to be cooler than the elevated levels suggested by at least one recent study byJohnson et al. (2008). While achieving temperatures above 273 K globally remains challenging, the additional warming by greenhouse gases under certain obliquity states can permit for widespread seasonally warm conditions, which can help to explain the presence of fluvial surface features (e.g., valley networks) and hydrous minerals of post‐Noachian age, a period when alternate methods do not convincingly explain the sustainability of liquid water. Furthermore, we find that global warming can be achieved with the presence of a darker surface globally, which is consistent with both widespread exposure of unweathered basaltic bedrock or the presence of a large surface ocean or sea.
Demagnetization by basin‐forming impacts on early Mars: Contributions from shock, heat, and excavation
Authors: Lillis Robert J. , Stewart Sarah T. , Manga Michael 
Published: April 2013

AbstractLarge hypervelocity impacts occurred frequently on ancient Mars, leaving many large impact basins visible today. After the planetary dynamo ceased operating, such impacts demagnetized the crust by way of (1) excavation of magnetized material, (2) heating, and (3) shock pressure. We investigate these three demagnetizing processes, both separately and in combination, using hydrocode simulations of large impacts on early Mars at a range of impact energies and using a new parameterization of the shock pressure‐demagnetization behavior of candidate Martian minerals. We find that in general, shock pressure demagnetization is more important than thermal demagnetization, except in the combined case of very large impacts (more than ~1026 J) and low Curie temperature minerals such as pyrrhotite. We find that total demagnetized area has a power law dependence on impact energy (with an exponent of 0.6–0.72) and that depending on the magnetic mineral, the demagnetized area resulting for a given impact energy can vary over approximately an order of magnitude. We develop an empirical model that can be used to calculate total demagnetized area for a given impact energy and magnetic mineral (whose pressure‐demagnetization properties are known). Once a reliable basin scaling law for ancient Mars (i.e., relating impact energy to final basin topography) is derived, this mineral parameterization and empirical model will allow robust constraints to be placed upon the primary Martian magnetic carrier(s).
The Low Energy of Concert in Many Symmetry‐Allowed Cycloadditions Supports a Stepwise‐Diradical Mechanism
Authors: Firestone Raymond A. 
Published: April 2013

ABSTRACTThe thesis of this paper is that orbital symmetry allowedness does not guarantee concert. The activation energy (Ea) for concerted Diels–Alder and 1,3‐dipolar cycloadditions must be substantially lower than that for a stepwise‐diradical pathway because the diradical has two fewer bonding electrons than anything on the concerted reaction coordinate, including the transition state. Two bonding electrons provide tens of kcal/mol of stabilization. The difference between the experimental Ea and that for diradicals is called the energy of concert (Econ). If experiment represents concert, Econ must be large, and if it represents diradicals Econ will be very small. In this paper, 42 examples are adduced in which firm experimental data show that Econ = 0. These cycloadditions cannot be concerted. While concert remains possible for all cycioadditions not proven stepwise, there is none with compelling evidence for concert.
Kinetic Analysis and Modeling of Thermal Decomposition of Ammonia Borane
Authors: Gangal Aneesh C. , Sharma Pratibha 
Published: April 2013

ABSTRACTAmmonia borane (AB; NH3BH3) is one of the most promising materials for hydrogen storage applications, mainly due to its high gravimetric hydrogen storage capacity of 19.6 wt%. In this paper, we present an exclusive kinetic analysis of AB thermolysis. Three methods are used for kinetic analysis of the thermal decomposition of AB, namely the Kissinger method, isoconversional model‐free fitting method, and solid‐state kinetics model–based method. Finally, a need to device a new model for thermal kinetics of AB was observed and hence a new kinetic model for AB thermolysis is proposed.