bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ferrocen-Derivate der Quadrat- und Propiolsäure. Synthesen und Reaktionen / Ferrocene Derivatives of Squaric Acid and Propiolic Acid. Syntheses and Reactions
Authors: Schottenberger Herwig , Buchmeiser Michael , Polin Johann , Schwarzhans Karl-Eberhard 
Published: March 2015

Concepts for linking ferrocene derivatives with conjugated squarate and propiolate based spacer systems have been investigated. Coupling of 3,4-dichlorocyclobut-3-ene-1,2-dione (squaric acid dichloride) with cuproferrocene • dimethylsulfide resulted in 3-chloro-4-ferrocenylcyclobut-3-ene-1,2-dione (ferrocenylsemisquaric acid chloride) and 3,4-diferrocenylcyclobut-3-ene-1,2-dione. Ferrocenylsemisquaric acid chloride was further treated with ethynylferrocene and 4-ethynyl-4-(ferrocenylethynyl)tolan, respectively, to form the corresponding mixed squaric diketones, which required Zn/Pd mediated coupling conditions for sufficient conversion. The symmetrically substituted derivative of ferrocenylacetylene was prepared by the same method.
Cupration and subsequent coupling of dilithioferrocene with one equivalent of iodopropiolic acid methyl ester yielded 1′-iodo- 1 -ferrocenylpropiolic acid methyl ester, and with two equivalents 1,16-bis(methoxycarbonylethynyl)biferrocene. Nucleophilic addition of secondary amines to ferrocenylpropiolic acid ethyl ester gave aminoacrylates as intermediates, which rapidly converted to ketoesters during workup. Only in the case of morpholine the corresponding adduct (ferrocenylmorpholino acrylate) could be isolated. 1,3-Diferrocenylprop-2-ene-1-one has been obtained in a Bénary reaction of lithioferrocene with 3-diethylaminoethyl acrylate in quantitative yield.
In order to provide alternative syntheses of already known compounds the substitution behavior of different metallated ferrocene intermediates has also been evaluated by reaction with other acid halides (oxalyl chloride, thiophosgene, ethyl chloroformate).
All new compounds, 3-chloro-4-ferrocenylcyclobut-3-ene-1,2-dione (1); 3,4-diferrocenylcyclobut-3-ene-1,2-dione (2); 3,4-diferrocenylethynylcyclobut-3-ene-1,2-dione (3); 3-ferrocenyl-4-ferrocenylethynylcyclobut-3-ene-1,2-dione (4); 3-ferrocenyl-4-ferrocenylethynylphenylethynylphenylethynylcyclobut-3-ene-1,2-dione (5); 3-(N-morpholino)-3-ferrocenylethyl acrylate (6); 3-ferrocenyl-3-ketoethyl propanoate (7); iodoferrocenylpropargylic acid methyl ester (8); 1,16-bis(methoxycarbonylethynyl)biferrocene (9) and trans-1,3-diferrocenylprop-2-ene-1-one [105 404-21-5], have been characterized by IR, MS and NMR and in several cases by UV/VIS and DSC.
tripod-Eisen- und tripod-Cobalt-Komplexe mit Acetonitril als Stützliganden (tripod = RCH2C(CH2PPh2)3; R = H, Ph) / tripod-Iron and tripod-Cobalt-Complexes with Acetonitrile as Supporting Ligands (tripod = RCH2C(CH2PPh2)3; R = H, Ph)
Authors: Asam A. , Janssen B. , Huttner G. , Zsolnai L. , Walter O. 
Published: March 2015

The tripod ligands RCH2C(CH2PPh2)3 react with (CH3CN)6Fe(BF4)2 to yield the tripod-Fe(II) complexes RCH2C(CH2PPh2)3Fe(CH3CN)3(BF4)2 (R = H, la; R = Ph, lb). The octahedral low spin Fe(II) compounds are shown by cyclic voltammetry to undergo reversible one electron oxidation at +1.47 V (vs. SCE) to give the corresponding Fe(III) derivatives.
In a similar way (CH3CN)6Co(BF4)2 reacts with the same tripod ligands to produce the tripod-Co(II) complexes RCH2C(CH2PPh2)3Co(CH3CN)2(BF4)2 (R = H, 2a; R = Ph, 2b). The compounds are paramagnetic (2a, g = 2.123; 2b, g = 2.129). The structure of complex 2b shows that the tripod ligand is facially coordinated with one longer (233.1 pm) and two shorter (about 222 pm) Co—P bonds. Reversible reduction is found for 2a at —0.30 V by cyclic voltammetry. The compounds have been characterized by spectroscopic and analytical techniques including X-ray analyses.
Genetic Mapping of Natural Variation in Schooling Tendency in the Threespine Stickleback
Authors: Greenwood Anna K , Ardekani Reza , McCann Shaugnessy R , Dubin Matthew E , Sullivan Amy , Bensussen Seth , Tavaré Simon , Peichel Catherine L 
Published: March 2015

AbstractAlthough there is a heritable basis for many animal behaviors, the genetic architecture of behavioral variation in natural populations remains mostly unknown, particularly in vertebrates. We sought to identify the genetic basis for social affiliation in two populations of threespine sticklebacks (Gasterosteus aculeatus) that differ in their propensity to school. Marine sticklebacks from Japan school strongly whereas benthic sticklebacks from a lake in Canada are more solitary. Here, we expanded on our previous efforts to identify quantitative trait loci (QTL) for differences in schooling tendency. We tested fish multiple times in two assays that test different aspects of schooling tendency: 1) the model school assay, which presents fish with a school of eight model sticklebacks; and 2) the choice assay, in which fish are given a choice between the model school and a stationary artificial plant. We found low-to-moderate levels of repeatability, ranging from 0.1 to 0.5, in schooling phenotypes. To identify the genomic regions that contribute to differences in schooling tendency, we used QTL mapping in two types of crosses: benthic × marine backcrosses and an F2 intercross. We found two QTL for time spent with the school in the model school assay, and one QTL for number of approaches to the school in the choice assay. These QTL were on three different linkage groups, not previously linked to behavioral differences in sticklebacks. Our results highlight the importance of using multiple crosses and robust behavioral assays to uncover the genetic basis of behavioral variation in natural populations.
Leveraging DNA Damage Response Signaling to Identify Yeast Genes Controlling Genome Stability
Authors: Hendry Jason A , Tan Guihong , Ou Jiongwen , Boone Charles , Brown Grant W 
Published: March 2015

AbstractOncogenesis frequently is accompanied by rampant genome instability, which fuels genetic heterogeneity and resistance to targeted cancer therapy. We have developed an approach that allows precise, quantitative measurement of genome instability in high-throughput format in the Saccharomyces cerevisiae model system. Our approach takes advantage of the strongly DNA damage-inducible gene RNR3, in conjunction with the reporter synthetic genetic array methodology, to infer mutants exhibiting genome instability by assaying for increased Rnr3 abundance. We screen for genome instability across a set of ~1000 essential and ~4200 nonessential mutant yeast alleles in untreated conditions and in the presence of the DNA-damaging agent methylmethane sulfonate. Our results provide broad insights into the cellular processes and pathways required for genome maintenance. Through comparison with existing genome instability screens, we isolated 130 genes that had not previously been linked to genome maintenance, 51% of which have human homologs. Several of these homologs are associated with a genome instability phenotype in human cells or are causally mutated in cancer. A comprehensive understanding of the processes required to prevent genome instability will facilitate a better understanding of its sources in oncogenesis.
Rapid and Efficient Identification ofCaenorhabditis elegansLegacy Mutations Using Hawaiian SNP-Based Mapping and Whole-Genome Sequencing
Authors: Jaramillo-Lambert Aimee , Fuchsman Abigail S , Fabritius Amy S , Smith Harold E , Golden Andy 
Published: March 2015

AbstractThe production of viable embryos requires the coordination of many cellular processes, including protein synthesis, cytoskeletal reorganization, establishment of polarity, cell migration, cell division, and in Caenorhabditis elegans, eggshell formation. Defects in any of these processes can lead to embryonic lethality. We examined six temperature-sensitive mutants as well as one nonconditional mutant that were previously identified in genetic screens as either embryonic lethal (maternal-effect or zygotic lethal) or eggshell defective. The responsible molecular lesion for each had never been determined. After confirmation of temperature sensitivity and lethality, we performed whole-genome sequencing using a single-nucleotide polymorphism mapping strategy to pinpoint the molecular lesions. Gene candidates were confirmed by RNA interference phenocopy and/or complementation tests and one mutant was further validated by CRISPR (Clustered Regularly Interspaced Short Palidromic Repeats)/Cas9 gene editing. This approach identified new alleles of several genes that had only been previously studied by RNA interference depletion. Our identification of temperature-sensitive alleles for all of these essential genes provides an extremely useful tool for further investigation for the C. elegans community, such as the ability to address mutant phenotypes at various developmental stages and the ability to carry out suppressor/enhancer screens to identify other genes that function in a specific cellular process.
A Systematic Mutational Analysis of a Histone H3 Residue in Budding Yeast Provides Insights into Chromatin Dynamics
Authors: Johnson Paige , Mitchell Virginia , McClure Kelsi , Kellems Martha , Marshall Sarah , Allison Mary K , Lindley Harrison , Nguyen Hoai-Trang T , Tackett Jessalyn E , Duina Andrea A 
Published: March 2015

Abstract
In previous work using the Saccharomyces cerevisiae model system, a mutant version of histone H3—H3-L61W—was found to confer a variety of abnormal growth phenotypes and defects in specific aspects of the transcription process, including a pronounced alteration in the distribution pattern of the transcription elongation factor Spt16 across transcribed genes and promotion of cryptic transcription initiation within the FLO8 gene. To gain insights into the contribution of the H3-L61 residue to chromatin function, we have generated yeast strains expressing versions of histone H3 harboring all possible natural amino acid substitutions at position 61 (H3-L61X mutants) and tested them in a series of assays. We found that whereas 16 of the 19 H3-L61X mutants support viability when expressed as the sole source of histone H3 in cells, all 19 confer abnormal phenotypes ranging from very mild to severe, a finding that might in part explain the high degree of conservation of the H3-L61 residue among eukaryotes. An examination of the strength of the defects conferred by each H3-L61X mutant and the nature of the corresponding substituted residue provides insights into structural features of the nucleosome required for proper Spt16−gene interactions and for prevention of cryptic transcription initiation events. Finally, we provide evidence that the defects imparted by H3-L61X mutants on Spt16−gene interactions and on repression of intragenic transcription initiation are mechanistically related to each other.
Synchrotron x-ray diffraction analysis of gadolinium and lanthanum titanate oxides irradiated by xenon and tantalum swift heavy ions
Authors: Park Sulgiye , Lang Maik , Tracy Cameron L. , Zhang Fuxiang , Trautmann Christina , Wang Zhongwu , Ewing Rodney C. 
Published: March 2015

ABSTRACTA synthetic cubic pyrochlore, Gd2Ti2O7 (Fd3̅m) irradiated with swift heavy ions is compared with a compositionally-related composition La2Ti2O7 (P21), which has a monoclinic, layered, perovskite-type structure. Irradiation experiments were performed at the GSI Helmholtz Center with 181Ta ions and 129Xe ions at specific energies of 11MeV/amu. At these energies the ions pass entirely through the sample thickness of ∼ 40 μm. Angle-dispersive synchrotron powder x-ray diffraction (XRD) measurements were completed and an increasing ion-induced amorphization with increasing ion fluence was for both phases. The ion track cross-sections for the radiation-induced crystalline-to-amorphous transformation, as determined from the evolution of the integrated peak intensities as a function of fluence, reveal that La2Ti2O7 (track diameter, d ∼ 7.2 nm with 181Ta and 5.1 nm with 129Xe) is more susceptible to amorphization than Gd2Ti2O7 (d ∼ 6.2 nm with 181Ta and 4.6 nm with 129Xe). The radiation response of the two titanate compounds can be understood in the context of their different structures and cation ionic radius ratios rA/rB, where the susceptibility of radiation of titanate pyrochlores is proportionate with this radius ratio. The higher electronic linear energy loss of the 181Ta ions as compared with 129Xe ions leads to a consistent increase of volume amorphized per ion in both materials, which manifests as a larger track diameter.
MANOS erase performance dependence on nitrogen annealing conditions
Authors: Ioannou-Sougleridis Vassilios , Nikolaou Nikolaos , Dimitrakis Panagiotis , Normand Pascal , Skarlatos Dimitrios , Travlos Anastasios , Kukli Kaupo , Niinisto Jaakko , Ritala Mikko , Leskela Markku 
Published: March 2015

ABSTRACTIn this work we examine the electrical characteristics and the memory properties of metal-alumina-nitride-oxide-silicon (MANOS) devices as a function of the post deposition annealing conditions. Post deposition annealing of the samples was performed at 850 or 1050°C in nitrogen ambient using two different processes: (1) Furnace annealing for 15 min and (2) rapid thermal annealing for 1 or 5 min. The capacitance equivalent thickness as extracted from the capacitance voltage characteristics depends strongly on the annealing process, being smallest for the furnace annealing. Furthermore, the experimental results indicate that the type of the annealing determines the defect state density of the Al2O3layer, via which the undesired effect of gate electrode electron injection takes place in the negative voltage regime. For inert ambient annealing the furnace process appears more efficient as compared to RTA.
Effects of Low Energy Carbon Ion Implantation on the Material Properties of InAs/GaAs Quantum Dots with Variation in Capping Layer
Authors: Upadhyay S. , Mandal A , Basu A. , Singh P. , Chakrabarti S. 
Published: March 2015

ABSTRACTUnder controlled irradiation of low energy carbon ions, photoluminescence (PL) study of InAs quantum dots prepared with different capping structures (GaAs and InAlGaAs) was carried out. Samples were investigated by varying implantation energy from 15 keV to 50 keV with fluence ranging between 3 × 1011ions/cm2 and 8 × 1011 ions/cm2. For fixed fluence of 4 × 1011ions/cm2, low temperature PL showed enhancement in a certain range of energy, along with a blue shift in the PL peak wavelength. In contrast, with varying fluence at fixed implantation energy of 50 keV, PL enhancement was not significant, rather a drop in PL intensity was noted at higher fluence from 5 × 1011 to 8 × 1011 ions/cm2. Moreover, carbon ion implantation caused a blue shift in the PL emission peak for both energy and fluence variations. PL intensity suppression was possibly caused by the formation of non-radiative recombination centers (NRCs) near the capping layer, while the corresponding blue shift might be attributed to stress generation in the capping layer due to implantation. As-grown and implanted InAlGaAs capped samples did not exhibit much variation in full width at half maxima of PL spectra; however, significant variation was observed for the GaAs capped sample. These results validate that InAlGaAs-capped QDs are more immune to ion implantation.
Ion Beam Irradiation Induced Structural Modifications in Iron Phosphate Glasses: A Model System for Understanding Radiation Damage in Nuclear Waste Glasses
Authors: Gandy Amy S. , Stennett Martin C. , Brigden Clive , Hyatt Neil C. 
Published: March 2015

ABSTRACTFe K-edge X-ray absorption spectroscopy (XAS) was applied to study the structural response of iron phosphate glasses to atomic displacements arising from ion beam irradiation, as an analogue of α-recoil damage arising from actinide immobilization. Analysis of XAS spectra demonstrated reduction of Fe3+ to Fe2+ as a consequence of 2 MeV Kr+ and 2 MeV Au+ implantation to a fluence of 2 x 1016 ions / cm2 and 5 x 1015 ions / cm2, respectively.
Differences in student and clinician perceptions of clinical competency in undergraduate physiotherapy
Authors: Lo Kristin , Osadnik Christian , Leonard Marcus , Maloney Stephen 
Published: March 2015

The ability of healthcare students to accurately self-reflect is crucial to the attainment of clinical competency; however limited research has been conducted in the physiotherapy profession. This study sought to determine a) whether ratings of clinical performance on a nationally standardised tool differ between students and their clinical educators; and b) whether the magnitude of agreement differs between ratings of clinical performance measured at two different time-points during clinical placements. From January 2012 until June 2013 undergraduate physiotherapy students and clinicians independently assessed students’ clinical competency via the Assessment of Physiotherapy Practice (APP) at midway and final assessments across all clinical placements. The mean degree of agreement was compared using the Bland-Altman method. Statistical analysis revealed a mean APP% score difference (student minus clinical educator) of -7.5% (95% limits of agreement 13.7 to -28.8%) at midway and -9.7% (95% limits of agreement 7.9 to -27.4%) at final assessment. This represents student ‘underestimation’ of their clinical competency. Considerable within-subject variability was evident from midway to final assessment. Further examination of student and clinical educator agreement in the evaluation of student performance during health professional clinical placements is indicated in light of recent research.
Effective Modeling and Analysis of Salt-Cavern Natural-Gas Storage
Authors: Barajas Pablo , Civan Faruk 
Published: March 2015

Summary
A rigorous modeling approach is developed for effective management and inventory analysis of natural-gas storage in underground salt caverns by considering the interactions of storage gas with surface facilities through wells and surrounding salt formations. Computational-fluid-dynamics (CFD) and heat-transfer-modeling approaches are used to simulate the strongly coupled fluid-mechanics and heat-transfer problems involving cavern gas storage. Implementation of effective numerical methods and algorithms successfully generates the wellbore-temperature and -pressure distributions; storage-gas-temperature, -pressure, and -velocity distributions; and temperature and pressure distributions of the gas leaking into the surrounding naturally fractured salt formation. Practical applications are performed concerning typical gas-injection, -storage, and -production scenarios and inventory analyses for both regular- and irregular-shaped caverns. Reversible and irreversible losses of natural gas into surrounding salt formations through natural defects, such as natural fractures, and defects resulting from deformation, ballooning, and aging effects are taken into account. The maximum amounts of gas that can be stored up to the pressure-safety limit of caverns are shown to vary with cavern shapes. Thus, the cavern-gas inventory analysis is not only dependent on temperature, pressure, and total volume of the cavern, but also the cavern shape. Accurate prediction of the natural-gas storage performance and inventories on the basis of the present comprehensive simulation approach can be instrumental in effective management and balancing of the natural-gas supply and demand.
Produced-Water-Reinjection Design and Uncertainties Assessment
Authors: Ochi J.. , Dexheimer D.. , Corpel P.V.. V. 
Published: March 2015

Summary
Produced-water reinjection (PWRI) is an important strategy for deriving value from waste water (Abou Sayed et al. 2005), but its implementation can face challenges related to injectivity and safety issues. Reinjection in a fracturing regime is often the only option to guarantee the sustainability of injectivity (Detienne et al. 2005), but it can present some risks to be anticipated early in the design phase.
The first objective of a PWRI-design study is to supply water-quality specifications to petroleum architects (in terms of solid and oil contents) to allow for the design of water-treatment facilities. The second objective is to supply injection-pressure specifications for the design of injection pumps and an injection network. These specifications must allow for sustaining well injectivity over the life of the field, while preventing any risk of caprock failure.
The water-quality specification is of prime importance because a maximum of contaminant injection is sought to minimize the cost related to water treatment, but at the same time, it must prevent any injectivity loss or excessive increase of pressure beyond which fracture confinement is no longer possible.
Water quality and injection pressure are thus linked to each other. They are deduced by simulation on a case-by-case basis. The modeling approach used by Total was presented in previous publications (Detienne et al. 1998, 2005; Ochi et al. 2007). The objective of this paper is to detail the manner in which the two parameters are deduced when uncertainties on input data are considered. Indeed, a workflow for uncertainty management based on experimental design and Monte Carlo theories was implemented to combine the simultaneous effect of a relatively large number of uncertain parameters, each of them being characterized by its own probabilistic distribution. Two-thousand simulations were run systematically, and water-quality and injection-pressure specifications were supplied with a probabilistic value (P10, P50, and P90). Application of this approach to real-design examples is detailed and discussed in this paper.
Multivariate Analysis and Data Mining of Well-Stimulation Data by Use of Classification-and-Regression Tree With Enhanced Interpretation and Prediction Capabilities
Authors: Maucec Marko , Singh Ajay P. , Bhattacharya Srimoyee , Yarus Jeffrey M. , Fulton Dwight D. , Orth Jon M. 
Published: March 2015

SummaryThe well-treatment program is an important part of the field-development plan, and certain variables, such as job-pause time (JPT) and fracture screenout, can affect its efficiency. JPT is the time during which pumping is paused between subsequent treatments of a job. Screenout occurs because of a sudden restriction of fluid flow inside the fracture and through the perforation. The objectives of this work are to investigate whether, from existing data, it is possible to find patterns in significant variables that affect the extreme values of JPT in a particular region, and what is the most critical variable causing screenout. The answers are sought by applying a classification-and-regression tree (CART) to both categorical and continuous variables in the database. The practical application of CART is presented by use of case studies containing JPT and screenout. Significant variables are found that affect the response variables, and predictor variables are ranked in the hierarchal order of their importance. Such information can be used to control predictor variables that cause high JPT or screenout.The results are outlined in an intuitive way, including categorical, continuous, and missing values. Because CART is a data-driven, deterministic model, one cannot calculate the confidence interval of the predicted response. The confidence in results is purely because of historical values, and the accuracy of the result produced by a tree model depends on the quality of recorded data measured in terms of volume, reliability, and consistency. The prediction capability of CART is enhanced by use of the normal-score transform and by dividing the data set into smaller groups by use of clustering. The approach presented in this paper analyzes a data set under limited information and high uncertainty and should lead to developing methodology for generating proxy models to find future success indices (e.g., one for drilling efficiency or production from a fracture). This could standardize stimulation and generate decision practices to save costs in field development and the optimization process.