bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standing wave modes observed in the South China Sea deep basin
Authors: Zheng Quanan , Hu Jianyu , Zhu Benlu , Feng Ying , Jo Young‐Heon , Sun Zhenyu , Zhu Jia , Lin Hongyang , Li Junyi , Xu Ying 
Published: June 2014

AbstractThis study deals with standing wave or seiche events using cruise observations, satellite altimeter data, and theoretical analysis. Cruise missions in summer 2007 and 2009 detected internal oscillation signals in the South China Sea (SCS) deep basin. The signals have average wavelengths of 320 and 390 km and the maximum amplitudes of 50–100 m at layers 500–700 m and 1500–1700 m. Satellite altimeter sea level anomaly (SLA) images and the second intrinsic mode function (IMF2) images derived from the empirical mode decomposition (EMD) analysis show that the observed internal oscillations are a portion of 2‐D seiche modes, which lasted for at least 2 weeks. We recognize that the observed internal oscillation signals represent seiche modes H5,3 and H5,1 derived from a rectangular model ocean basin with a uniform depth, a west‐east length of 1000 km and a north‐south width of 800 km. Statistical analysis of standing wave modes H4,0, H5,1, and H5,3 with the average wavelength of 500, 390, and 320 km indicates that from 1993 to 2012 (1045 weeks), total 94 events with total temporal coverage of 218 weeks are affirmed. The total occurrence frequency is 20.9%. Histograms of annual distributions of seiche events and timespans show an interannual variability of about 9 years, with peak years 1993, 1994, 1998, 2001, and 2011. While monthly distributions show an intraseasonal variability double‐peaked in May and October, transit periods of East Asia monsoon in the SCS.
On the upscaling of chemical transport in fractured rock
Authors: Cvetkovic Vladimir , Gotovac Hrvoje 
Published: June 2014

AbstractThe impact of flow heterogeneity on chemical transport from single to multiple fractures is investigated. The emphasis is on the dynamic nature of the specific surface area (SSA) due to heterogeneity of the flow, relative to a purely geometrical definition. The flow‐dependent SSA is interpreted probabilistically, following inert tracer particles along individual fractures. Upscaling to a fracture network is proposed as a time domain random walk based on the statistics of SSA for single fractures. Statistics of SSA are investigated for three correlation structures of transmissivity: multi‐Gaussian and two non‐multi‐Gaussian. The mean of SSA stabilizes after ∼20 fractures at different values depending on whether the cubic or quadratic hydraulic law is assumed. The results are tested against comprehensive DFN simulations based on site‐specific data but also against direct estimates from a wider range of tracer tests. The proposed time domain random walk methodology sets bounds for SSA in a 75% confidence interval as ∼1800 1/m and 27,000 1/m, with a median of 14,000 1/m; these values capture reasonably well both the DFN simulation and tracer test SSA data. Presented results may be particularly relevant when quantifying uncertainty of reactive transport modeling in fractured rock.
The delivery of dissolved organic carbon from a forested hillslope to a headwater stream in southeastern Pennsylvania, USA
Authors: Mei Yi , Hornberger George M. , Kaplan Louis A. , Newbold J. Denis , Aufdenkampe Anthony K. 
Published: June 2014

AbstractRiparian soils, rich in organic carbon, act as a source of dissolved organic carbon (DOC) to the adjacent stream, but the hydrologic factors that control the delivery of DOC are not well characterized. A mechanistic two‐dimensional, variably saturated flow and reactive transport finite element model (FEM) was developed to explore both biodegradable DOC (BDOC) and refractory DOC (RDOC) delivery processes during storms for a hillslope transect in a southeastern Pennsylvania Piedmont watershed. The model indicated that DOC concentrations in outflow from a hillslope peaked on the falling limb of the discharge hydrograph, a temporal sequence consistent with a flushing hypothesis. Factors that control the lag time between the stream water peak discharge and peak DOC concentration were analyzed using a Monte Carlo simulation coupled with a multiple linear regression. The results are consistent with previous studies showing that the majority of DOC delivered to a stream during storms originates from the riparian zone. Further, the model suggests that the duration of the flood wave and hydraulic properties of the riparian soil play important roles in controlling the lag time between peak discharge and peak DOC concentration in outflow from a hillslope.
Regioselective Copper(II)‐Mediated Bromoamination of Unfunctionalized Olefins: An Efficient Route to N‐Heterocyclic Compounds
Authors: Liu Gong‐Qing , Ding Zhen‐Ying , Zhang Li , Li Ting‐Ting , Li Lin , Duan Lili , Li Yue‐Ming 
Published: June 2014

AbstractBromoamination of unfunctionalized olefins was realized under mild conditions using copper(II) bromide (CuBr2) as both reaction promoter and bromine source. The reactions could be carried out under open air at ambient temperature, and both N‐alkylated and N‐tosylated substrates could be converted to the corresponding N‐heterocyclic compounds in high regioselectivity and good isolated yields. A variety of biologically important structures could be obtained via subsequent nucleophilic substitution reactions.magnified image
Chiral 2,3‐Disubstituted Indolines from Indoles and Aldehydes by Organocatalyzed Tandem Synthesis Involving Reduction by Trichlorosilane
Authors: Chen Lin , Wang Chao , Zhou Li , Sun Jian 
Published: June 2014

AbstractThe organocatalytic trichlorosilane reduction system has been successfully utilized to develop a multi‐step tandem approach for the easy preparation of chiral 2‐methyl‐3‐alkylindolines starting from simple 2‐methylindoles and aldehydes. A broad range of chiral 2‐methyl‐3‐alkylindoline products was obtained with high yields and enantioselectivities and excellent stereoselectivities by this approach.magnified image
A Palladium(II)‐Catalyzed Synthesis of α‐Ketoamides via Chemoselective Aroyl Addition to Cyanamides
Authors: Guin Srimanta , Rout Saroj Kumar , Gogoi Anupal , Ali Wajid , Patel Bhisma K. 
Published: June 2014

AbstractAn acyl moiety generated from α‐oxocarboxylic acids via decarboxylation undergoes a palladium‐catalyzed chemoselective insertion into organic cyanamides to afford N‐monosubstituted α‐ketoamides.magnified image
Catalytic Isonitrile Insertions and Condensations Initiated by RNC–X Complexation
Authors: Chakrabarty Suravi , Choudhary Shruti , Doshi Arpit , Liu Fa‐Qiang , Mohan Rishabh , Ravindra Manasa P. , Shah Dhruv , Yang Xun , Fleming Fraser F. 
Published: June 2014

AbstractIsonitriles are delicately poised chemical entities capable of being coaxed to react as nucleophiles or electrophiles. Directing this tunable reactivity with metal and non‐metal catalysts provides rapid access to a large array of complex nitrogenous structures ideally functionalized for medicinal applications. Isonitrile insertion into transition metal complexes has featured in numerous synthetic and mechanistic studies, leading to rapid deployment of isonitriles in numerous catalytic processes, including multicomponent reactions (MCR). Covering the literature from 1990–2014, the present review collates reaction types to highlight reactivity trends and allow catalyst comparison.magnified image
Photocatalytic Synthesis of Oxetane Derivatives by Selective CH Activation
Authors: Ravelli Davide , Zoccolillo Matteo , Mella Mariella , Fagnoni Maurizio 
Published: June 2014

AbstractThe selective C(sp3)H activation at position 2 in oxetanes has been accomplished by decatungstate photocatalysis under mild conditions. The resulting α‐oxy radicals were trapped by electron‐poor olefins resulting in the smooth preparation of 2‐substituted oxetanes. The chemoselectivity in hydrogen abstraction in substituted oxetanes containing other H donating groups, such as CH2OH, CH2OAc and CHO, has been demonstrated in intramolecular models.magnified image
Metal‐Free Preparation of Cycloalkyl Aryl Sulfides via Di‐tert‐butyl Peroxide‐Promoted Oxidative C(sp3)H Bond Thiolation of Cycloalkanes
Authors: Zhao Jincan , Fang Hong , Han Jianlin , Pan Yi , Li Guigen 
Published: June 2014

AbstractA concise thiolation of the C(sp3)H bond of cycloalkanes with diaryl disulfides in the presence of the oxidant di‐tert‐butyl peroxide (DTBP) has been developed. This reaction, without using any metal catalyst, tolerates varieties of disulfides and cycloalkanes substrates, giving good to excellent chemical yields, and thus provides a useful approach to cycloalkyl aryl sulfides from unactivated cycloalkanes.magnified image
One‐Step C‐Terminal Deprotection and Activation of Peptides with Peptide Amidase from Stenotrophomonas maltophilia in Neat Organic Solvent
Authors: Arif Muhammad I. , Toplak Ana , Szymanski Wiktor , Feringa Ben L. , Nuijens Timo , Quaedflieg Peter J. L. M. , Wu Bian , Janssen Dick B. 
Published: June 2014

AbstractChemoenzymatic peptide synthesis is a rapidly developing technology for cost effective peptide production on a large scale. As an alternative to the traditional C→N strategy, which employs expensive N‐protected building blocks in each step, we have investigated an N→C extension route that is based on activation of a peptide C‐terminal amide protecting group to the corresponding methyl ester. We found that this conversion is efficiently catalysed by Stenotrophomonas maltophilia peptide amidase in neat organic media. The system excludes the possibility of internal peptide cleavage as the enzyme lacks intrinsic protease activity. The produced peptide methyl ester was used for peptide chain extension in a kinetically controlled reaction by a thermostable protease.magnified image
Photo‐Assisted Multi‐Component Reactions (MCR): A New Entry to 2‐Pyrimidinethiones
Authors: Guo Haiheng , Zhu Chenghao , Li Jian , Xu Guangyang , Sun Jiangtao 
Published: June 2014

AbstractA photo‐assisted metal‐free multi‐component dehydrogenative condensation has been developed. This multi‐component reaction (MCR) has been realized under mild reaction conditions especially under household light irradiation. As a result, the novel tetrahydropyrimidines (THPMs) were obtained in moderate yields and excellent stereoselectivities. Moreover, the approach provided an easy construction of a variety of 2‐pyrimidinethiones from the commonly used cyclic ethers.magnified image
An Experimental Study on the Structural and Mechanical Properties of Polyvinyl Alcohol Sponge Using Different Stress–Strain Definitions
Authors: Karimi Alireza , Navidbakhsh Mahdi , Haghi Afsaneh Motevalli 
Published: June 2014

AbstractPolyvinyl alcohol (PVA) sponge with a complex interconnecting porous structure indicates suitable mechanical properties at different strain rates. The paper presents the first scientific study to show how different results are given by the various definitions of stress–strain used and to recommend a specific definition when calculating the energy absorption characteristics of the PVA sponge. A series of tensile tests on PVA sponges are carried out. Three stress definitions (second Piola–Kirchhoff stress, engineering stress, and true stress) and four strain definitions (Almansi–Hamel strain, Green–St. Venant strain, engineering strain, and true strain) are used to determine the modulus of resilience and modulus of toughness. The stress–strain curves of PVA sponges show a near constant plateau stress over a long strain range, which is ideal for energy absorption applications. The results reveal that the Green–St. Venant strain definition has the highest modulus of resilience (3000 J/m3) and toughness (56,900 J/m3) at different definitions of stress and may overestimate the modulus of resilience and toughness. The Almansi–Hamel strain definition exhibits the lowest modulus of resilience (1760 J/m3) and toughness (4850 J/m3) at different stress definitions and may underestimate these values. The results also show that the effect of varying the stress definition on the modulus of toughness measurements is significant but not when calculating the modulus of resilience. The true stress–true strain definition favors spongy material mechanics since it gives more accurate measurements of the sponge's response using the instantaneous values.
Duplication of 20qter and deletion of 20pter due to paternal pericentric inversion: Patient report and review of 20qter duplications
Authors: Starr Lois J. , Truemper Edward J. , Pickering Diane L. , Sanger Warren G. , Olney Ann Haskins 
Published: June 2014

AbstractDuplications of the terminal long arm of chromosome 20 are rare chromosomal anomalies. We report a male infant found on array comparative genomic hybridization analysis to have a 19.5 Mb duplication of chromosome 20q13.12‐13.33, as well as an 886 kb deletion of 20p13 at 18,580–904,299 bp. This anomaly occurred as the recombinant product of a paternal pericentric inversion. There have been 23 reported clinical cases involving 20qter duplications; however, to our knowledge this is only the second reported patient with a paternal pericentric inversion resulting in 46,XY,rec(20)dup(20q). This patient shares many characteristics with previously described patients with 20qter duplications, including microphthalmia, anteverted nares, long ears, cleft palate, small chin, dimpled chin, cardiac malformations, and normal intrauterine growth. While there is variable morbidity in patients with terminal duplications of 20q, a review of previously reported patients and comparison to our patient's findings shows significant phenotypic similarity. © 2014 Wiley Periodicals, Inc.
Substrate‐Guided Front‐Face Reaction Revealed by Combined Structural Snapshots and Metadynamics for the Polypeptide N‐Acetylgalactosaminyltransferase 2
Authors: Lira‐Navarrete Erandi , Iglesias‐Fernández Javier , Zandberg Wesley F. , Compañón Ismael , Kong Yun , Corzana Francisco , Pinto B. Mario , Clausen Henrik , Peregrina Jesús M. , Vocadlo David J. , Rovira Carme , Hurtado‐Guerrero Ramon 
Published: June 2014

AbstractThe retaining glycosyltransferase GalNAc‐T2 is a member of a large family of human polypeptide GalNAc‐transferases that is responsible for the post‐translational modification of many cell‐surface proteins. By the use of combined structural and computational approaches, we provide the first set of structural snapshots of the enzyme during the catalytic cycle and combine these with quantum‐mechanics/molecular‐mechanics (QM/MM) metadynamics to unravel the catalytic mechanism of this retaining enzyme at the atomic‐electronic level of detail. Our study provides a detailed structural rationale for an ordered bi–bi kinetic mechanism and reveals critical aspects of substrate recognition, which dictate the specificity for acceptor Thr versus Ser residues and enforce a front‐face SNi‐type reaction in which the substrate N‐acetyl sugar substituent coordinates efficient glycosyl transfer.
Isolierung eines nicht‐Heteroatom‐stabilisierten Goldcarbens
Authors: Hussong Matthias W. , Rominger Frank , Krämer Petra , Straub Bernd F. 
Published: June 2014

AbstractGoldcarben‐Komplexe sind essentielle Intermediate in vielen Gold‐katalysierten synthetischen Transformationen. Während Goldcarbene mit direkter, vinyloger oder phenyloger Heteroatomstabilisierung schon synthetisiert und charakterisiert worden sind, waren elektronisch nichtstabilisierte Goldcarbene bislang schwer zu beobachten. Wir haben nun einen sterisch extrem abgeschirmten, smaragdgrünen Komplex [IPr**Au=CMes2]+[NTf2]− synthetisiert, isoliert und vollständig charakterisiert. Sein Absorptionsmaximum bei 642 nm, im Vergleich zu 528 nm des rotpurpurnen Carbokations [Mes2CH]+, zeigt klar, dass Gold mehr ist als nur ein “weiches Proton”.
Hydrogenation of Sulfoxides to Sulfides under Mild Conditions Using Ruthenium Nanoparticle Catalysts
Authors: Mitsudome Takato , Takahashi Yusuke , Mizugaki Tomoo , Jitsukawa Koichiro , Kaneda Kiyotomi 
Published: June 2014

AbstractThe first demonstration of the hydrogenation of sulfoxides under atmospheric H2 pressure is reported. The highly efficient reaction is facilitated by a heterogeneous Ru nanoparticle catalyst. The mild reaction conditions enable the selective hydrogenation of a wide range of functionalized sulfoxides to the corresponding sulfides. The high redox ability of RuOx nanoparticles plays a key role in the hydrogenation.
A 3,4‐trans‐Fused Cyclic Protecting Group Facilitates α‐Selective Catalytic Synthesis of 2‐Deoxyglycosides
Authors: Balmond Edward I. , Benito‐Alifonso David , Coe Diane M. , Alder Roger W. , McGarrigle Eoghan M. , Galan M. Carmen 
Published: June 2014

AbstractA practical approach has been developed to convert glucals and rhamnals into disaccharides or glycoconjugates with high α‐selectivity and yields (77–97 %) using a trans‐fused cyclic 3,4‐O‐disiloxane protecting group and TsOH⋅H2O (1 mol %) as a catalyst. Control of the anomeric selectivity arises from conformational locking of the intermediate oxacarbenium cation. Glucals outperform rhamnals because the C6 side‐chain conformation augments the selectivity.
Isolation of a Non‐Heteroatom‐Stabilized Gold–Carbene Complex
Authors: Hussong Matthias W. , Rominger Frank , Krämer Petra , Straub Bernd F. 
Published: June 2014

AbstractGold–carbene complexes are essential intermediates in many gold‐catalyzed organic‐synthetic transformations. While gold–carbene complexes with direct, vinylogous, or phenylogous heteroatom substitution have been synthesized and characterized, the observation in the condensed phase of electronically non‐stabilized gold–carbenes has so far remained elusive. The sterically extremely shielded, emerald‐green complex [IPr**Au=CMes2]+[NTf2]− has now been synthesized, isolated, and fully characterized. Its absorption maximum at 642 nm, in contrast to 528 nm of the red‐purple carbocation [Mes2CH]+, clearly demonstrates that gold is more than just a “soft proton”.
Sperm whale occurrence, site fidelity and population structure along the Hellenic Trench (Greece, Mediterranean Sea)
Authors: Frantzis Alexandros , Alexiadou Paraskevi , Gkikopoulou Kalliopi Charitomeni 
Published: June 2014

ABSTRACTTwelve summer surveys conducted each year between 1998 and 2009 along the Hellenic Trench have been analysed to provide information about a previously unknown sperm whale population unit. Sperm whales were detected acoustically 238 times; 178 of these led to a visual encounter with social units (96), male aggregations (45), solitary males (32) or unclassified groups (5). The overall detection rate was 10.9 detections per 1000 km of acoustic effort.A pronounced peak in sperm whale density was observed along the 1000 m depth contour: 74% of visual encounters (corrected for effort) were within 3 km of this contour. Density decreased both in shallower waters and deeper waters further offshore.One hundred and eighty‐one whales were photo‐identified. Fifty‐seven percent of 136 social unit members and 36% of 25 males segregated from social units were encountered in multiple years. Social units were resighted in up to six different years spanning 9 years (15 if opportunistic photo‐identifications are included). Several males were resighted in three different years usually spanning up to 4 years. This indicates a high level of site fidelity.The mean group size was 2.47 (range = 1–5) for males and 8.21 (range = 4–13) for social units. Maximum group size reached 15 whales when casual visitors were included. The 16 identified social units were generally stable although some individuals moved between social units, and some social units split or mixed. Female to male sex ratio was 1.55:1 within social units and 1.06:1 overall.Calves (≤2 years old) were present in 79% of social unit encounters, accounting for 16.6% of social unit members. Observations of 15 newborns indicate a mid‐summer calving season.This study indicates that the Hellenic Trench is core habitat for the eastern Mediterranean sperm whale sub‐population. This population, which is very small, is believed not to exceed a few hundred individuals. Given the endangered status of the entire Mediterranean population, managing threats in this area and creating a marine protected area for sperm whales along the Hellenic Trench is a conservation priority.Copyright © 2014 John Wiley & Sons, Ltd.
Nutrient media optimization for simultaneous enhancement of the laccase and peroxidases production by coculture of Dichomitus squalens and Ceriporiopsis subvermispora
Authors: Kannaiyan Ranjani , Mahinpey Nader , Kostenko Victoria , Martinuzzi Robert J. 
Published: June 2014

AbstractCoculturing of two white‐rot fungi, Dichomitus squalens and Ceriporiopsis subvermispora, was explored for the optimization of cultivation media for simultaneous augmentation of laccase and peroxidase activities by response surface methodology (RSM). Nutrient parameters chosen from our previous studies with the monocultures of D. squalens and C. subvermispora were used to design the experiments for the cocultivation study. Glucose, arabinose, sodium nitrate, casein, copper sulfate (CuSO4), and manganese sulfate (MnSO4) were combined according to central composite design and used as the incubation medium for the cocultivation. The interaction of glucose and sodium nitrate resulted in laccase and peroxidase activities of approximately 800 U/g protein. The addition of either glucose or sodium nitrate to the medium also modifies the impact of other nutrients on the ligninolytic activity. Both enzyme activities were cross‐regulated by arabinose, casein, CuSO4, and MnSO4 as a function of concentrations. Based on RSM, the optimum nutrient levels are 1% glucose, 0.1% arabinose, 20 mM sodium nitrate, 0.27% casein, 0.31 mM CuSO4, and 0.07 mM MnSO4. Cocultivation resulted in the production of laccase of 1,378 U/g protein and peroxidase of 1,372 U/g protein. Lignin (16.9%) in wheat straw was degraded by the optimized enzyme mixture.
An ethnographic study of consumer financial sophistication
Authors: Estelami Hooman 
Published: June 2014

ABSTRACTExisting research profiling consumer financial sophistication has examined specific decision errors that consumers may make in financial matters. While these errors have been replicated in multiple studies over the years, most have emerged from highly controlled experimental settings or through consumer surveys that measure only specific categories of financial behavior. This paper extends existing research on financial sophistication by utilizing an ethnographic study conducted over a 5‐year time period. Results indicate that while some of the traditional categories of decision errors defined in earlier research affect consumers, decision errors not thoroughly examined in previous academic studies can have a notable and growing effect on consumers' financial decisions. Emerging categories of financial decision errors are identified, and shifts in consumers' financial behavior resulting from the financial crisis are profiled. Copyright © 2014 John Wiley & Sons, Ltd.
Molecular Origin of pH‐Dependent Fibril Formation of a Functional Amyloid
Authors: McGlinchey Ryan P. , Jiang Zhiping , Lee Jennifer C. 
Published: June 2014

AbstractFibrils derived from Pmel17 are functional amyloids upon which melanin is deposited. Fibrils of the repeat domain (RPT) of Pmel17 form under strict melanosomal pH (4.5–5.5) and completely dissolve at pH≥6. To determine which Glu residue is responsible for this reversibility, aggregation of single, double, and quadruple Ala and Gln mutants were examined by intrinsic Trp fluorescence, circular dichroism spectroscopy, and transmission electron microscopy. Charge neutralization of E404, E422, E425, or E430, which are located in the putative amyloid‐forming region, modulated aggregation kinetics. Remarkably, the removal of a single negative charge at E422, one of 16 carboxylic acids, shifted the pH dependence by a full pH unit. Mutation at E404, E425, or E430 had little to no effect. We suggest that protonation at E422 is essential for initiating amyloid formation and that the other Glu residues play an allosteric role in fibril stability.