bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of the Species OH(A2Σ+), OH(X2Π and CH(X2Π) in the System C2H2/O/H
Authors: Grebe J. , Homann K. H. 
Published: July 2012

AbstractOH*(A 2Σ+) and OH(X2Π) concentration‐time‐profiles were measured in the gas phase reaction system C2H2/O/H at 2.66 mbar and 298 K in a discharge flow system for largely varying initial conditions. The well established chemiluminescence reaction CH + O2 → OH*(A2Σ+) + CO connects the experimental OH*(A2Σ+) concentrations to the concentrations of the intermediate CH(X 2Π) which is an important precursor of higher hydrocarbons. Computer analysis showed that the reaction CH2 + H → CH + H2 is the major CH formation reaction with a rate constant k4 of about 5 · 1013 cm3 mol−1 s−1. Reaction CH2 + O → CH + OH does not contribute significantly to either CH or OH formation. A rate constant k28 = 4.8 · 1010 cm3 mol−1 s−1 was obtained.
Micellisation Processes in Concentrated Sodium Deoxycholate Solutions – Effect of Different Counterions
Authors: Sesta B. , La Mesa C. , Bonincontro A. , Cametti C. , Di Biasio A. 
Published: July 2012

AbstractThe effect of different electrolytes (NaBr, CsBr, Bu4NBr) on the micellisation processes of Sodium Deoxycholate solutions has been studied by means of various experimental techniques (densimetric, viscometric and microwave dielectric measurements) in the concentration range above the first critical micelle concentration. The size and shape of the secondary micelles are estimated and the role of the interfacial water in these aggregation processes discussed.
Neuere Untersuchungen zur Bindung von Ethidiumbromid an DNA 4. Mitteilung: Betain B
Authors: Roding Joachim , Zimmermann Herbert W. 
Published: July 2012

AbstractBetaine B (8‐amino‐5‐ethyl‐3‐oxido‐6‐phenylphenanthridinium‐betaine) is bound to DNA as protonated cation BH⊕ (8‐amino‐5‐ethyl‐3‐hydroxy‐6‐phenylphenanthridinium‐cation). BH⊕ is a hydroxy derivative of the ethidium cation E. Its binding to calf thymus DNA has been investigated by means of absorption spectroscopy. From binding isotherms we determined the binding constants of the non‐competitive binding (intercalation) K1 = 0.9 · 104 M−1 and the competitive binding (external binding) K2 = 1.0 · 106 M−1 using NaCl as competitor, T = 298 K. The constant K1 of the intercalation is much more smaller than the constant K2 of the external binding. Similar properties has the ethidium cation E. – Unprotonated betaine B isn't bound to DNA. In a range of middle pH‐values there exists an equilibrium in solution between the free unprotonated betaine B and the protonated bound betaine BH⊕. The free enthalpy of binding of BH⊕ to DNA forces the protonation of the base B.
The Viscosity of Carbon‐Monoxide and its Mixtures with Other Gases in the Temperature Range 25 – 200°C
Authors: Kestin J. , Ro S. T. , Wakeham W. A. 
Published: July 2012

AbstractThe paper reports new, absolute measurements of the viscosity of carbon monoxide, nitrogen, of two of their binary mixtures, and of mixtures of carbon monoxide with helium, neon and argon. The measurements have been carried out in an oscillating disk viscometer at a pressure of 0.1 MPa in the temperature range 25 – 200°C. The accuracy of the absolute viscosities reported is estimated to lie between ±0.1 and ±0.2%. The measurements have been conducted in such a way that the ratios of the viscosity of carbon‐monoxide and its mixtures with nitrogen to that of pure nitrogen were determined directly with an uncertainty of no more than ±0.1%. The viscosity ratios are found to depart from unity by no more than this uncertainty over the entire temperature range studied. – The viscosity data for all of the systems studied have been correlated, within their experimental error, by means of the extended law of corresponding states. The experimental results have been employed to derive binary diffusion coefficients of the gas mixtures. In the particular cases of CO – He and CO – Ar, the experimental data have also been used to examine the kinetic theory description of the results of recent measurements of the thermal conductivity at low and moderate density and near room temperature.
Diatomic Molecule Electronic Structure beyond Simple Molecular Constants
Authors: Field Robert W. 
Published: July 2012

AbstractMolecules with partly filled 3d or 4f shells have a surprisingly large number of low lying electronic states, resulting in incredibly complex spectra. This paper attempts to show that, although the spectra are complicated, the explanation of the global electronic structure is quite simple. Ligand Field Theory displays all of the important relationship between the dN or fN structures in the free‐atomic‐ion and the molecule. The splitting of the core into numerous substates causes a gratuitous repetition and intermingling of the usual ϱ, π‐valence structures which are so familiar for molecules with filled‐shell cores. The 4f electron is shown to be a useful probe of the unknown structures of more diffuse valence orbitals. A semi‐empirical theory is described which allows important features of the molecular level diagram to be predicted using atomic energy level tables and a scrap of paper. The same theory provides a basis for detailed numerical parametrization and quantitative predictions of energy levels, perturbation matrix elements, hfs splittings, and transition intensities.
Molecular Orbital Theories and the Structural Properties of Molecules
Authors: Pople J. A. 
Published: July 2012

AbstractThe use of theoretical models in predictions of equilibrium geometries of molecules is reviewed. If the basis set is taken to the split‐valence + polarization level and if the electron is included by Møller‐Plesset perturbation theory to third order, theoretical structures are found to lie within experimental error ranges for the majority of small molecules that have been investigated. The application of the same techniques to unstable intermediates is illustrated by some studies on the vinylidene‐acetylene rearrangement.
Laser Spectroscopy of Iodine Monofluoride Produced in Situ in a Molecular Beam Experiment
Authors: Trautmann M. , Trickl T. , Wanner J. 
Published: July 2012

AbstractNascent IF molecules in various vibrational‐rotational manifolds of the electronic ground state have been prepared in a molecular beam experiment. High‐resolution laser spectroscopy has been applied to determine accurate band head positions and band origins of the B→X transition. Dunham coefficients have been calculated for the X1Σ+ and B3Π(O+) states. The hyperfine structure of the rotational lines has been observed.
Molecular Ions Formed by Field Ionization
Authors: Block J. H. 
Published: July 2012

AbstractThe formation of ions in high electric fields in front of field emitters is investigated by mass spectrometry and appearance spectroscopy. The combination of these methods provides information on ion generating processes and molecular properties in high electric fields. For noble gases ionization potentials are determined, for hydrogen (H+, H2+, H3+) detailed information is given for ionization, field‐induced dissociation, and surface interaction (H3+). Protonated rare gas molecular ions are formed by a fast adiabatic proton stripping, without reflecting values of proton affinities in appearance energies. Field‐induced surface reactions form sulfur chains (Sx, x ≦ 22) from S2 molecules, while ring structures (Sx, with x = 8 most abundant) predominate when field pulse desorption with zero reaction field is applied. Cluster‐ions with low internal binding energy (like (H2O)n · H+, n ≦ 12) are formed at low temperatures and by using photon‐induced field desorption.
Energy Levels for Photoinjection of Excess Electrons into Ammonia Vapor at Various Densities — The Transition from the Quasi‐Free to the Localized Electron State
Authors: Krebs P. , Bukowski K. , Giraud V. , Heintze M. 
Published: July 2012

AbstractThe energy of the electronic levels in ammonia vapor which are populated by the photoinjection of excess electrons has been determined in the density range from 1.7 · 1017 to 2.3 . 1021 molecules/cm3 at T = 400 K. The method used is based on measuring the photoelectric work function of a stainless steel photocathode immersed in ammonia vapor with respect to that into vacuum. From these measurements the chemical potential of two bands of electron injection levels can be elucidated. These results are discussed together with electron mobilities which show with increasing vapor density a transition from the quasi‐free to the localized electron state. It will be shown that the onset of electron localization obeys Mott's criterion for quantum localization. From these results together with the optical absorption spectra of solvated electrons, and from theoretical considerations it follows that one of the injection bands is the conduction band. The other one is formed by pre‐existing solvent traps. Therefore, in contrast to the conventional assumption in the theory of photoemission, the electron injection into polar media does not occur only in the conduction band but also in pre‐existing trap states (band‐tail states) thus supporting Thompson's recent assertion. This requires the reinterpretation of existing data on photoemission of electrons into polar solvents (electrolytes) including the photoionization of solute molecules in polar solvents in order to determine the bottom of the conduction band V0.
Molecular Motions and Phase Transitions in [(CH3)4N]2MBr6 (M: Pt, Te, Sn). A Proton Magnetic Relaxation, Differential Thermal Analysis, and Powder X‐Ray Diffraction Study
Authors: Sato Setsuko , Ikeda Ryuichi , Nakamura Daiyu 
Published: July 2012

AbstractThe measurements of the temperature dependences of the proton spin‐lattice relaxation time T1 and of the second moment of proton NMR absorptions as well as the experiments of DTA and X‐ray powder diffraction were carried out in tetramethylammonium(tetMA) hexabromo‐platinate(IV),‐tellurate(IV), and ‐stannate(IV). From the DTA experiments, various phases were found for (tetMA)2PtBr6 while three phases for both of the remaining complexes. At room temperature, the three complexes crystallize with the Fd3c cubic structure, while they form the Fm3m type cubic crystals in their highest‐temperature phase. The lattice constants of each complex in both of these phases were determined. The second moment study revealed that the reorientational motions of the cations in these complexes freeze for the most part at nearly the same temperature, but a small fraction of the motional freedom still remains even at 77 K. A broad and also deep T1 minimum accompanied by a shallow one on the low‐temperature side was obtained in the T1 measurements of all of these complexes. The broad T1 minimum can be attributed to both of the C3 reorientation of the four methyl groups and the isotropic reorientation of the cation, while the shallow one to a small‐angle reorientation of the methyl groups about their respective C3 axes through the all‐staggered conformation of the cation. The activation energies were evaluated for various motional modes detected.
Automatic segmentation and supervised learning‐based selection of nuclei in cancer tissue images
Authors: Nandy Kaustav , Gudla Prabhakar R. , Amundsen Ryan , Meaburn Karen J. , Misteli Tom , Lockett Stephen J. 
Published: July 2012

AbstractAnalysis of preferential localization of certain genes within the cell nuclei is emerging as a new technique for the diagnosis of breast cancer. Quantitation requires accurate segmentation of 100–200 cell nuclei in each tissue section to draw a statistically significant result. Thus, for large‐scale analysis, manual processing is too time consuming and subjective. Fortuitously, acquired images generally contain many more nuclei than are needed for analysis. Therefore, we developed an integrated workflow that selects, following automatic segmentation, a subpopulation of accurately delineated nuclei for positioning of fluorescence in situ hybridization‐labeled genes of interest. Segmentation was performed by a multistage watershed‐based algorithm and screening by an artificial neural network‐based pattern recognition engine. The performance of the workflow was quantified in terms of the fraction of automatically selected nuclei that were visually confirmed as well segmented and by the boundary accuracy of the well‐segmented nuclei relative to a 2D dynamic programming‐based reference segmentation method. Application of the method was demonstrated for discriminating normal and cancerous breast tissue sections based on the differential positioning of the HES5 gene. Automatic results agreed with manual analysis in 11 out of 14 cancers, all four normal cases, and all five noncancerous breast disease cases, thus showing the accuracy and robustness of the proposed approach. © Published 2012 Wiley Periodicals, Inc.
Investigation into the experimental protocols required to determine maximum residue limits (MRLs) in honey
Authors: Fussell Richard J. , Heinrich Katharina , Dickinson Michael , Wilkins Selwyn , Roelofs Victoria , Murray Alistair , Kay Jack F. , Sharman Matthew 
Published: July 2012

There is current debate within the EU, and internationally, on how withdrawal periods and maximum residue limits (MRLs) may be set for honey production. Whilst comprehensive EU guidelines exist for calculating the withdrawal times of veterinary medicines in most food‐producing species, the analytical variables to be studied for bees/honey are not well defined. The objective of this study was therefore to investigate and understand the factors, for example sampling variability, that is important in the development of a harmonized protocol that can be used to generate the robust scientific data necessary to assist risk assessors in proposing MRLs for honey.Ten bee colonies were treated in the spring with a model compound (ciprofloxacin). One hive was used to study intra‐hive variation in residue concentrations and the other nine were used in an inter‐hive study over a 41‐week sampling period. All samples were analyzed using liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). The highest mean concentration from nine hives used in the inter‐hive study was 4627 µg/kg eight days (D8) after treatment. The concentration of ciprofloxacin declined to an average concentration of 1756 µg/kg at D30 and 733 µg/kg at D283 (over‐winter sample). A generalized additive model was used to fit a smooth curve for trend estimation. For some individual hives the concentration of ciprofloxacin increased slightly at the later sampling time‐points. Consequently it was not possible to interpolate, with confidence, a finite withdrawal period for ciprofloxacin at theoretical MRLs between 25 and 500 µg/kg. The observed variation in concentration of ciprofloxacin between hives indicates that the validity of the EU guideline for bees/honey, which requires five samples from five hives to calculate a withdrawal period, may require revision. © 2012 Crown copyright. Drug Testing and Analysis © 2012 John Wiley & Sons, Ltd.
Microscopic Origin for Multistability in a Photomagnetic CoFe Prussian Blue Analogue
Authors: Lejeune Julien , Cafun Jean‐Daniel , Fornasieri Giulia , Brubach Jean‐Blaise , Creff Gaëlle , Roy Pascale , Bleuzen Anne 
Published: July 2012

AbstractSwitchable compounds attract growing interest, as they offer promising perspectives for high‐density storage applications. Much effort has been invested in understanding the mechanisms involved in such properties, in order to prepare systems that are suitable for real applications. Compounds exhibiting an electronic transition that can be triggered by an external stimulus have been extensively studied. While most studies describe the switching properties of such systems in terms of a two‐state model, the existence of multistability in switchable systems remains a controversial topic. In thispaper, we compare the thermally populated CoIIFeIII and photoinduced (CoIIFeIII)* states of the Na2Co4[Fe(CN)6]3.3·14H2O Prussian blue analogue. The comparison of the infrared spectroscopic data for the two CoIIFeIII and (CoIIFeIII)* states shows differences at a microscopic scale that cannot be explained in terms of a two‐state model. These experimental data suggest a change in the coordination sphere of the sodium cation, which strongly supports a displacement of the sodium cation in the lattice between the two states. This direct evidence of several distinct CoFe states at an atomic level in this system highlights a new kind of multistability involving competitive metal‐to‐ligand interactions in a switchable compound.
Trenbolone causes mortality and altered sexual differentiation in Xenopus tropicalis during larval development
Authors: Olmstead Allen W. , Kosian Patricia A. , Johnson Rodney , Blackshear Pamela E. , Haselman Jonathan , Blanksma Chad , Korte Joseph J. , Holcombe Gary W. , Burgess Emily , Lindberg-Livingston Annelie , Bennett Blake A. , Woodis Kacie K. , Degitz Sigmund J. 
Published: July 2012

Abstract
Trenbolone is an androgen agonist used in cattle production and has been measured in aquatic systems associated with concentrated animal-feeding operations. In this study, the authors characterized the effects of aqueous exposure to 17β-trenbolone during larval Xenopus tropicalis development. Trenbolone exposure resulted in increased mortality of post-Nieuwkoop–Faber stage 58 tadpoles at concentrations ≥100 ng/L. Morphological observations and the timing of this mortality are consistent with hypertrophy of the larynx. Development of nuptial pads, a male secondary sex characteristic, was induced in tadpoles of both sexes at 100 ng/L. Effects on time to complete metamorphosis or body sizes were not observed; however, grow-outs placed in clean media for six weeks were significantly smaller in body size at 78 ng/L. Effects on sex ratios were equivocal, with the first experiment showing a significant shift in sex ratio toward males at 78 ng/L. In the second experiment, no significant effects were observed up to 100 ng/L, although overall sex ratios were similar. Histological assessment of gonads at metamorphosis showed half with normal male phenotypes and half that possessed a mixed-sex phenotype at 100 ng/L. Hypertrophy of the Wolffian ducts was also observed at this concentration. These results indicate that larval 17β-trenbolone exposure results in effects down to 78 ng/L, illustrating potential effects from exposure to androgenic compounds in anurans. Environ. Toxicol. Chem. 2012; 31: 2391–2398. © 2012 SETAC
Associations of insulin‐like growth factor and insulin‐like growth factor binding protein‐3 with mortality in women with breast cancer
Authors: Duggan Catherine , Wang Ching‐Yun , Neuhouser Marian L. , Xiao Liren , Smith Ashley Wilder , Reding Kerryn W. , Baumgartner Richard N. , Baumgartner Kathy B. , Bernstein Leslie , Ballard‐Barbash Rachel , McTiernan Anne 
Published: July 2012

AbstractElevated circulating insulin‐like growth factor‐1 (IGF‐1), a breast epithelial cell mitogen, is associated with breast cancer development. However, its association with breast cancer survival is not established. Circulating concentrations of IGF‐1 are controlledviabinding proteins, including IGF Binding Protein‐3 (IGFBP‐3), that may modulate the association of IGF‐1 with breast‐cancer outcomes. We measured IGF‐1 and IGFBP‐3 concentrations in serum from 600 women enrolled in the health, eating, activity, and lifestyle (HEAL) study, a multiethnic, prospective cohort study of women diagnosed with stage I‐IIIA breast cancer. We evaluated the association between IGF‐1 and IGFBP‐3, and as a ratio, modeled using quintile cut‐points, with risk of breast cancer‐specific (n= 42 deaths) and all‐cause mortality (n= 87 deaths) using Cox proportional hazards models. In models adjusted for body mass index, ethnicity, tamoxifen use at time of blood draw, treatment received at diagnosis and IGFBP‐3, women in the highest quintile of IGF‐1 level had an increased risk of all‐cause mortality (Hazard Ratio (HR) = 3.10, 95% CI 1.21–7.93,p= 0.02), although no dose‐response association was evident. The IGF‐1/IGFBP‐3 ratio, an indicator of free IGF‐I levels, was significantly associated with increasing risk of all‐cause mortality (HR = 2.83, 95% CI 1.25–6.36ptrend= 0.01, uppervs. lower quintile) in a fully adjusted model. In conclusion, high serum levels of IGF‐1 and the IGF‐1/IGFBP‐3 ratio were associated with increased risk of all‐cause mortality in women with breast cancer. These results need to be confirmed in larger breast cancer survivor cohorts.
Effects of an Ostracod (Cypris pubera) on the Rotifer Keratella tropica: Predation and Reduced Spine Development
Authors: Gilbert John J. 
Published: July 2012

AbstractThis study investigates two different effects of an ostracod on a rotifer. The rotifer Keratella tropica and the ostracod Cypris pubera were cultured on the alga Cryptomonas erosa. Adult ostracods (2.2 mm body length) significantly reduced the population growth rate (r day–1) of K. tropica from 0.42 to 0.13. Individuals of this size ingested live rotifers and produced fecal pellets with rotifer loricas. Smaller ostracods (both 0.59 and 1.61 mm body lengths) did not affect K. tropica 's population growth rate. Surprisingly, C. pubera significantly inhibited spine development in K. tropica. Rotifers cultured with juvenile, non‐predatory ostracods had similar lorica lengths but right and left posterior spines that were 10 and 30% shorter, respectively. The spine reduction induced by the ostracod kairomone is in striking contrast to the spine elongation induced in this rotifer by kairomones from copepods, cladocerans and Asplanchna. In shallow ecosystems, large ostracods that swim in the plankton may be important predators of rotifers. In addition, the presence of ostracods in plankton communities may be one of many factors affecting rotifer spine development. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Involvement of the adrenal glands and testis in gap junction formation via testosterone within the male rat anterior pituitary gland
Authors: Sakuma Eisuke , Wada Ikuo , Otsuka Takanobu , Wakabayashi Kenjiro , Ito Kinya , Soji Tsuyoshi , Herbert Damon C. 
Published: July 2012

AbstractWe investigated the influence of testicular and adrenal androgens on the presence of gap junctions between folliculo‐stellate cells in the anterior pituitary glands of 60‐day‐old Wistar‐Imamichi strain male rats. The animals were separated into six groups: Group A served as the controls and had free access to a normal diet and water, Group B was given a normal diet and 0.9% NaCl for their drinking water as the controls of adrenalectomized groups, Group C was castrated, Group D was adrenalectomized, Group E was both castrated and adrenalectomized, and Group F was also both castrated and adrenalectomized. In addition, the animals of Group F were administered a dose of testosterone that is known to produce high physiological levels of the hormones in plasma. Five rats from each group were sacrificed 1, 2, 3, 4, 5, 6, and 7 days after their respective operation, and the anterior pituitary glands were removed and prepared for observation by transmission electron microscopy. We quantified the number of follicles and gap junctions and calculated the rate of occurrence as the ratio of the number of gap junctions existing between folliculo‐stellate cells per intersected follicle profile. Simultaneous removal of adrenal glands with castration resulted in a significantly decrease in the number of gap junctions, whereas the administration of testosterone to these rats compensated for this change. These observations indicate that the preservation of gap junctions between folliculo‐stellate cells is mainly dependent on androgens from both the testes and adrenal glands in adult male rats. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.