bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal variability of North Atlantic tropical cyclones
Authors: Done James M. , Bruyère Cindy L. , Ge Ming , Jaye Abigail 
Published: May 2014

AbstractUsing a regional model initial condition ensemble, this study quantifies the magnitude of internal variability of North Atlantic tropical cyclone frequency for a case study year and identifies potential physical sources. For tropical cyclone formations from easterly waves, the simulated internal variability of tropical cyclone frequency for 1998 is approximately two fifths of the total (externally forced and internal) variability of observed tropical cyclone frequency. The simulated internal variability of tropical cyclone frequency is found to arise in approximately equal measure from variability of easterly wave occurrence and development and variability of the transition from incipient warm cores to tropical cyclones. Variable interaction between developing tropical cyclones and vertical wind shear associated with upper level cyclones is identified as a potentially important contributing factor to tropical cyclone internal variability.
Operating Principles
Authors: Bargende Michael , Schmidt Dietmar , Berner Hans‐Jürgen , Grill Michael 
Published: May 2014

AbstractAll types of internal combustion engines (ICEs) have a working chamber limited by rigid walls, with one movable wall to enable volume changes; this is usually accomplished by a piston. Power is produced by the volume change, which in turn is generated by the variable gas pressure of the working volume in the cylinder. Different strategies can be applied to manage the processes as efficiently as possible for different applications.This chapter classifies the different working principles used in existing ICEs and also briefly describes about possible future concepts. The classification includes an overview of spark‐ and compression‐ignition combustion principles and alternative concepts such as homogeneous charge compression ignition (HCCI) combustion.ICEs are most conveniently described and classified by way of certain characteristic design properties and performance measures, which allow for quantitative comparisons. This chapter defines the most common characteristic properties of ICEs, such as the compression ratio, the air/fuel ratio, and various efficiencies. In particular, the section on ICE efficiency provides a general formulation of efficiency that expresses all relevant efficiencies in one equation.The chapter ends with the description of some widely used metrics specific to ICEs, including mean effective pressures, specific fuel consumption, and mean piston speed. Finally, some examples of typical engine maps and tables are given.
Straightforward Synthesis of the Brønsted Acid hfipOSO3H and its Application for the Synthesis of Protic Ionic Liquids
Authors: Beichel Witali , Panzer Johann M. U. , Hätty Julian , Ye Xiaowei , Himmel Daniel , Krossing Ingo 
Published: May 2014

AbstractThe easily accessible hexafluoroisopropoxysulfuric acid (1, hfipOSO3H; hfip=C(H)(CF3)2) was synthesized by the reaction of hexafluoroisopropanol and chlorosulfonic acid on the kilogram scale and isolated in 98 % yield. The calculated gas‐phase acidity (GA) value of 1 is 58 kJ mol−1 lower in ΔG° than that of sulfuric acid (GA value determined by a CCSD(T)‐MP2 compound method). Considering the gas‐phase dissociation constant as a measure for the intrinsic molecular acid strength, a hfipOSO3H molecule is more than ten orders of magnitude more acidic than a H2SO4 molecule. The acid is a liquid at room temperature, distillable at reduced pressure, stable for more than one year in a closed vessel, reactive towards common solvents, and decomposes above 180 °C. It is a versatile compound for further applications, such as the synthesis of ammonium‐ and imidazolium‐based air‐ and moisture‐stable protic ionic liquids (pILs). Among the six synthesized ionic compounds, five are pILs with melting points below 100 °C and three of them are liquids at nearly room temperature. The conductivities and viscosities of two representative ILs were investigated in terms of Walden plots, and the pILs were found to be little associated ILs, comparable to conventional aprotic ILs.
In‐vitro‐Rekonstitution eines zellulären Phasenübergangs unter Beteiligung der mRNA‐Decapping‐Maschinerie
Authors: Fromm Simon A. , Kamenz Julia , Nöldeke Erik R. , Neu Ancilla , Zocher Georg , Sprangers Remco 
Published: May 2014

AbstractIn eukaryotischen Zellen können die Komponenten des 5′‐3′‐Abbaumechanismus der Boten‐RNA (mRNA) einen schnellen Phasenübergang durchlaufen. Die resultierenden zytoplasmatischen Zentren werden Processing Bodys (P‐bodys) genannt. Allerdings sind die zugrundeliegenden molekularen Details dieser Selbstaggregation weitgehend unbestimmt. Wir wenden hier eine Bottom‐up‐Methode an, um zu testen, ob mRNA‐Abbaufaktoren Phasenübergänge in vitro durchlaufen können. Dieser Ansatz umfasst NMR‐Spektroskopie, isotherme Titrationskalometrie, Röntgenkristallographie und Fluoreszenzmikroskopie. Wir zeigen, dass das Dcp2‐Decapping‐Enzym der Spalthefe Schizosaccharomyces pombe, sein Hauptaktivator Dcp1 sowie die Gerüstproteine Edc3 und Pdc1 ausreichen, um einen Phasenübergangsprozess einzuleiten. Zwischenmolekulare Wechselwirkungen zwischen der Edc3‐LSm‐Domäne und mindestens zehn helikalen, leucinreichen Motiven in Dcp2 und Pdc1 bilden den Kern des Wechselwirkungsnetzwerks. Wir zeigen, dass die Blockade dieser Wechselwirkungen das Clusteringverhalten in vitro und in vivo behindert.
Visible‐Light‐Induced Electron Transport from Small to Large Nanoparticles in Bimodal Gold Nanoparticle‐Loaded Titanium(IV) Oxide
Authors: Naya Shin‐ichi , Niwa Tadahiro , Kume Takahiro , Tada Hiroaki 
Published: May 2014

AbstractA key to realizing the sustainable society is to develop highly active photocatalysts for selective organic synthesis effectively using sunlight as the energy source. Recently, metal‐oxide‐supported gold nanoparticles (NPs) have emerged as a new type of visible‐light photocatalysts driven by the excitation of localized surface plasmon resonance of Au NPs. Here we show that visible‐light irradiation (λ>430 nm) of TiO2‐supported Au NPs with a bimodal size distribution (BM‐Au/TiO2) gives rise to the long‐range (>40 nm) electron transport from about 14 small (ca. 2 nm) Au NPs to one large (ca. 9 nm) Au NP through the conduction band of TiO2. As a result of the enhancement of charge separation, BM‐Au/TiO2 exhibits a high level of visible‐light activity for the one‐step synthesis of azobenzenes from nitrobenzenes at 25 °C with a yield greater than 95 % and a selectivity greater than 99 %, whereas unimodal Au/TiO2 (UM‐Au/TiO2) is photocatalytically inactive.
Combining Photoredox‐Catalyzed Trifluoromethylation and Oxidation with DMSO: Facile Synthesis of α‐Trifluoromethylated Ketones from Aromatic Alkenes
Authors: Tomita Ren , Yasu Yusuke , Koike Takashi , Akita Munetaka 
Published: May 2014

AbstractTrifluoromethylated ketones are useful building blocks for organic compounds with a trifluoromethyl group. A new and facile synthesis of ketones with a trifluoromethyl substituent in the α‐position proceeds through a one‐pot photoredox‐catalyzed trifluoromethylation–oxidation sequence of aromatic alkenes. Dimethyl sulfoxide (DMSO) serves as a key and mild oxidant under these photocatalytic conditions. Furthermore, an iridium photocatalyst, fac[Ir(ppy)3] (ppy=2‐phenylpyridine), turned out to be crucial for the present photoredox process.
Construction and DNA Condensation of Cyclodextrin‐Coated Gold Nanoparticles with Anthryl Grafts
Authors: Zhao Di , Chen Yong , Liu Yu 
Published: May 2014

AbstractThe condensation of DNA in a controlled manner is one of the key steps in gene delivery and gene therapy. For this purpose, a water‐soluble supramolecular nanostructure is constructed by coating 14 β‐cyclodextrins onto the surface of a gold nanoparticle, followed by the noncovalent association of different amounts of anthryl‐modified adamantanes with coated β‐cyclodextrins. The strong binding of β‐cyclodextrins with anthryl adamantanes (KS=8.61×104 M−1) efficiently stabilizes the supramolecular nanostructure. Spectrophotometric fluorescence spectra and microscopic studies demonstrated that, with many anthryl grafts that can intercalate in the outer space of the DNA double helix, this supramolecular nanostructure showed good condensation abilities to calf thymus DNA. Significantly, the condensation efficiency of supramolecular nanostructure towards DNA could be conveniently controlled by adjusting the ratio between gold nanoparticles and anthryl adamantane grafts, leading to the formation of DNA condensates of a size that are suitable for the endocytosis of hepatoma cells, which will make it potentially applicable in many fields of medicinal science and biotechnology.
Wurster’s Blue‐type Cation Radicals Framed in a 5,10‐Dihydrobenzo[a]indolo[2,3‐c]carbazole (BIC) Skeleton: Dual Electrochromism with Drastic Changes in UV/Vis/NIR and Fluorescence
Authors: Suzuki Takanori , Sakano Yuto , Tokimizu Yusuke , Miura Youhei , Katoono Ryo , Fujiwara Kenshu , Yoshioka Naoki , Fujii Nobutaka , Ohno Hiroaki 
Published: May 2014

AbstractElectron‐donating dihydrobenzindolocarbazoles (BICs) 1 a–c, which adopt planar disk‐shaped geometries, were prepared by gold(I)‐catalyzed cyclization as a key step. Due to the presence of a 1,4‐phenylenediamine (PD) moiety in the framework, they undergo reversible one‐electron oxidation to the corresponding Wurster’s Blue (WB)‐type species that exhibits NIR absorptions up to λ=1200 nm. In the case of the N,N′‐dimethyl derivative, cation radical 1 c+. is stable enough to be isolated as a salt and X‐ray analysis indicated paraquinoid‐type bond alternation in the WB core unit, whereas the bond lengths in the peripheral benzene rings are identical to those in the neutral donor. Upon electrochemical interconversion, the redox pairs of 1 a–c and 1 a–c+. exhibited an electrochromic response in the UV/Vis/NIR region, which was accompanied by a drastic change in the fluorescence spectrum because only neutral donors 1 a–c are highly emissive (ΦF: 0.7–0.8).
Analysis of 10 systemic pesticide residues in various baby foods using liquid chromatography–tandem mass spectrometry
Authors: Yang Angel , Abd El‐Aty A. M. , Park Jong‐Hyouk , Goudah Ayman , Rahman Md. Musfiqur , Do Jung‐Ah , Choi Ok‐Ja , Shim Jae‐Han 
Published: May 2014

ABSTRACTTen systemic pesticides, comprising methomyl, thiamethoxam, acetamiprid, carbofuran, fosthiazate, metalaxyl, azoxystrobin, diethofencarb, propiconazole, and difenoconazole, were detected in 13 baby foods (cereals, boiled potatoes, fruit and milk) using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) for sample preparation and liquid chromatography tandem mass spectrometry for analysis. The matrix‐matched calibration curves showed good linearity with determination coefficients (R2) > 0.992. The limits of detection and quantitation were 0.0015–0.003 and 0.005–0.01 mg/kg, respectively. The mean recoveries of three different concentrations ranged from 69.2 to 127.1% with relative standard deviations <20%. The method was successfully applied to 13 actual samples collected from a local market, and none of the samples were found to contain pesticide residues. This method is suitable for the identification and quantification of systemic pesticides with matrix‐matched standards in various baby foods. Copyright © 2013 John Wiley & Sons, Ltd.
Determination of anxiolytic veterinary drugs from biological fertilizer blood meal using liquid chromatography high‐resolution mass spectrometry
Authors: Choi Jeong‐Heui , Lamshöft Marc , Zühlke Sebastian , Park Jong‐Hyouk , Rahman Md. Musfiqur , El‐Aty A. M. Abd , Spiteller Michael , Shim Jae‐Han 
Published: May 2014

ABSTRACTA liquid environment‐friendly agricultural material originating from animal blood, blood meal, was employed to detect anxiolytic veterinary drugs using a combination of liquid–liquid extraction (LLE) and positive electrospray ionization Orbitrap mass spectrometry. Every positive ion of the analytes was consistent with [M + H]+, and the accurate mass analysis and mass spectral filtration with a 2‐ppm mass tolerance window were applied to identify and quantitate the analytes and metabolites. The developed LLE method was validated with the lowest calibrated level, linearity (r2), recovery, repeatability and the within‐laboratory reproducibility, which were in the ranges of 0.3–1 µg/L, 0.9963–0.9995, 48.3–117.5%, 1.1–12.6% and 2.3–15.7%, respectively. The LLE method was compared with a solid‐phase extraction (SPE) method; however, its recoveries were <70% for most of the analytes despite good repeatability of 1.2–7.4%. The analytes and the ascertained acepromazine, azaperone and xylazine metabolites were monitored in four actual liquid blood meal samples, and none of the targeted compounds were observed. Copyright © 2013 John Wiley & Sons, Ltd.
Quantitation of sulfur‐containing amino acids, homocysteine, methionine and cysteine in dried blood spot from newborn baby by HPLC‐fluorescence detection
Authors: Wada Mitsuhiro , Kuroki Mana , Minami Yuu , Ikeda Rie , Sekitani Yui , Takamura Noboru , Kawakami Shigeru , Kuroda Naotaka , Nakashima Kenichiro 
Published: May 2014

ABSTRACTSulfur‐containing amino acids (SAAs), homocysteine (Hcy), methionine (Met) and cysteine (Cys) in blood are related to homocystinuria, an inborn error of metabolism. In this study, an assay method with HPLC‐fluorescence detection to quantify the SAAs in a dried blood spot was established and applied to samples from newborn babies (n = 200). Sample pretreatment involving reduction, derivatization with 4‐(N,N‐dimethylaminosulfonyl)‐7‐fluoro‐2,1,3‐benzoxadiazole, and liquid–liquid extraction with ethyl acetate gave the separation of the derivatives with retention times within 12 min. The method was enough sensitive to determine the SAAs in a dried blood spot with 0.04–0.14 µm as the limit of detection at a signal‐to‐noise ratio of 3. However, the absolute recoveries were very low (5.7% for Hcy, 4.6% for Cys) except for Met (105.4%) owing to inefficient recovery of Hcy and Cys from the blood matrix. Other validation parameters such as accuracy (93.5–106.2%) and intra‐ (≤9.0%) and inter‐day precisions (≤8.7%) were acceptable. The reliability of a dried blood spot as an analytical sample was estimated. Furthermore, the proposed method was successfully applied to dried blood spots prepared from newborn babies. Copyright © 2014 John Wiley & Sons, Ltd.
Recent advances in proteomics: towards the human proteome
Authors: Wang Kui , Huang Canhua , Nice Edouard 
Published: May 2014

ABSTRACTAfter the successful completion of the Human Genome project in 2003, the next major challenge was to understand when and where the encoded proteins were expressed, and to generate a map of the complex, interconnected pathways, networks and molecular systems (the human proteome) that, taken together, control the workings of all cells, tissues, organs and organisms. Proteomics will be fundamental for such studies. This review summarizes the key discoveries that laid down the foundations for proteomics as we now know it, and describes key recent technological advances that will undoubtedly contribute to achieving the initial goal of the Human Proteome Organization of identifying and characterizing at least one protein product and representative post‐translational modifications, single amino acid polymorphisms and splice variant isoforms from the 20,300 human protein‐coding genes within the next 10 years. Successful unraveling of the human proteome will undoubtedly improve our understanding of human biology at the cellular level and lay the foundations for improved diagnostic, prognostic, therapeutic and preventive medical outcomes as we enter the era of personalized medicine. Copyright © 2014 John Wiley & Sons, Ltd.
A dispersive liquid–liquid microextraction method based on the solidification of a floating organic drop combined with HPLC for the determination of lovastatin and simvastatin in rat urine
Authors: Zhao Longshan , Zhao Pan , Wang Linli , Ma Xiaowei , Hou Xiaohong , Li Famei 
Published: May 2014

ABSTRACTA dispersive liquid–liquid microextraction method based on solidification of floating organic drop combined with HPLC was developed for the determination of lovastatin and simvastatin in rat urine for the first time. 1‐Dodecanol and methanol were used as the extraction and disperser solvents, respectively. Several important parameters influencing the micro‐extraction efficiency were studied and systematically optimized, including the type and volume of extraction solvent and disperser solvent, extraction time, pH and salt concentration. The analytes were separated on a Kromasil C18 column at 30°C with a mobile phase of methanol and 0.2% acetic acid in water (83:17, v/v) and detected at 238 nm. Under the optimal conditions, the maximum number of enrichment factors for both analytes was 27. The linear ranges were 20.08–1004 and 20.00–1000 µg/L with the correlation coefficients ranging from 0.9990 to 0.9994 for lovastatin and simvastatin, respectively. The volume of organic solvent consumed in extraction was <0.3 mL, and the extraction time was 10 min. The newly developed environment‐friendly sample pretreatment method will be a good alternative to conventional techniques, such as solid‐phase extraction, liquid–liquid extraction and protein precipitation, for the HPLC determination of lovastatin and simvastatin in biological samples. Copyright © 2014 John Wiley & Sons, Ltd.
Determination of protein‐unbound rhynchiphylline brain distribution by microdialysis and ultra‐performance liquid chromatography with tandem mass spectrometry
Authors: Lee Chia‐Jung , Hsueh Thomas Y. , Lin Lie‐Chwen , Tsai Tung‐Hu 
Published: May 2014

ABSTRACTThe stem with hook of Uncaria rhynchophylla (Chinese herbal name Gou‐Teng) is a traditional Chinese medicine that has been ethnopharmacologically used to extinguish wind and clean interior heat. Rhynchophylline (RHY), a tetracyclic oxindole alkaloid isolated from U. rhynchophylla, displays significant antineuroinflammatory effects. However, there is no evidence to indicate that rhynchophylline can cross the blood–brain barrier and be detected in the brain. In this study, an in vivo microdialysis sampling method coupled with UPLC/MS/MS was employed for the continuous simultaneous monitoring of unbound RHY in rat blood and brain. The precursor ion → product ion transition at m/z 385.2 → 160.0 for rhynchophylline was monitored. A calibration curve gave good linearity (r > 0.996) over the concentration range from 0.5 to 1000 ng/mL. The results demonstrated that rhynchophylline could be detected in the brain and plasma from 15 min to 6 h after its administration (1 or 10 mg/kg, i.v.). All the pharmacokinetic parameters of rhynchophylline in the brain and plasma were obtained. These results show that rhynchophylline can cross the blood–brain barrier and they provide useful clinical information. Copyright © 2014 John Wiley & Sons, Ltd.
Tailoring Photoluminescence Properties in Ionic Nanoparticle Networks
Authors: Kronstein Martin , Akbarzadeh Johanna , Drechsel Christina , Peterlik Herwig , Neouze Marie‐Alexandra 
Published: May 2014

AbstractTo investigate the original and promising luminescence properties of ionic nanoparticle networks (INN), various material compositions were investigated. In this work, the linker used to network the silica nanoparticles was varied; numerous substituted or non‐substituted imidazolium, pyrazolium and pyridinium linkers are presented. Photoluminescence experiments on the INN hybrid materials revealed strong emission bands over a broad range in the visible region of the light spectrum. Varying the aromatic linker between the imidazolium units induced clear shifts of the emission maxima up to 100 nm, as a consequence of π–π stacking interactions. Steric hindrance and inductive effects of the substituents, introduced on the aromatic units, also strongly influenced the luminescence properties of the materials by modifying the π–π stacking between the imidazolium rings. Small and wide‐angle X‐ray scattering (SAXS, WAXS) experiments revealed a clear trend between the obtained structural parameters (short‐range order parameter and distance of the aromatic units within the hybrid material) and the luminescence quantum yields of the INN materials.
Direct Metal‐Catalyzed Regioselective Functionalization of Enamides
Authors: Gigant Nicolas , Chausset‐Boissarie Laëtitia , Gillaizeau Isabelle 
Published: May 2014

AbstractEnamides are stable enamine surrogates and provide key intermediates for the synthesis of small but complex nitrogen‐containing compounds. Metal‐catalyzed regioselective functionalization of enamides provides a rapid method to synthesize useful nitrogen containing heterocycles. This review discloses the recent progress made in the development of the CH functionalization of enamides involving efficient and atom‐economical routes. Syntheses of different heterocycles are classified based on the site reactivity of enamides and key mechanistic insights are given for each transformation.
Transition‐Metal‐Ion‐Mediated Polymerization of Dopamine: Mussel‐Inspired Approach for the Facile Synthesis of Robust Transition‐Metal Nanoparticle–Graphene Hybrids
Authors: Yang Liping , Kong Junhua , Zhou Dan , Ang Jia Ming , Phua Si Lei , Yee Wu Aik , Liu Hai , Huang Yizhong , Lu Xuehong 
Published: May 2014

AbstractInspired by the high transition‐metal‐ion content in mussel glues, and the cross‐linking and mechanical reinforcement effects of some transition‐metal ions in mussel threads, high concentrations of nickel(II), cobalt(II), and manganese(II) ions have been purposely introduced into the reaction system for dopamine polymerization. Kinetics studies were conducted for the Ni2+–dopamine system to investigate the polymerization mechanism. The results show that the Ni2+ions could accelerate the assembly of dopamine oligomers in the polymerization process. Spectroscopic and electron microscopic studies reveal that the Ni2+ions are chelated with polydopamine (PDA) units, forming homogeneous Ni2+–PDA complexes. This facile one‐pot approach is utilized to construct transition‐metal‐ion–PDA complex thin coatings on graphene oxide, which can be carbonized to produce robust hybrid nanosheets with well‐dispersed metallic nickel/metallic cobalt/manganese(II) oxide nanoparticles embedded in PDA‐derived thin graphitic carbon layers. The nickel–graphene hybrid prepared by using this approach shows good catalytic properties and recyclability for the reduction ofp‐nitrophenol.
Direct In Situ Nitridation of Nanostructured Metal Oxide Deposited Semiconductor Interfaces: Tuning the Response of Reversibly Interacting Sensor Sites
Authors: Laminack William I. , Gole James L. 
Published: May 2014

AbstractMetal‐oxide nanostructure‐decorated extrinsic semiconductor interfaces modified through in situ nitridation greatly expand the range of sensor interface response. Select metal‐oxide sites, deposited to an n‐type nanopore‐coated microporous interface, direct a dominant electron‐transduction process for reversible chemical sensing, which minimizes chemical‐bond formation. The oxides are modified to decrease their Lewis acidity through a weak interaction to form metal oxynitride sites. Conductometric and X‐ray photoelectron spectroscopy measurements demonstrate that in situ treatment changes the reversible interaction with the analytes NH3 and NO. The sensor range is extended, which creates a distinct new family of responses determined by the Lewis acidity/basicity of a given analyte relative to that of the nanostructures chosen to decorate the interface. The analyte response, broadened in a substantial and predictable way by nitridation, is explained by the recently developing inverse hard/soft acid/base model (IHSAB) of reversible electron transduction.