bluuebunny/crossref_metadata_2025_split huggingface dataset:
FTMS Studies of Sputtered Metal Cluster Ions: (II) The Chemistry of Nin+ with C2H4 and CH4 at Long Timescales
Authors: Irion Manfred P. , Selinger Adrian 
Published: July 2012

AbstractNickel cluster cations, generated in an external source by sputtering with 20 keV Xe+ were transferred to the ICR cell of a Fourier transform mass spectrometer (FTMS), collisionally cooled, and trapped for long time periods. During storage, the chemistry of Nin+ was studied with ethylene and methane in the range n = 1 … 20. Rather than undergoing adsorption as an intact unit, C2H4 was dehydrogenated in the 1.2‐position to yield HCCH adducts Nin(C2H2)m+ with a dramatic size‐specificity: Whereas Nin+ ions proved absolutely inert for n = 1, 3, 4, they were found highly reactive from n = 5 on. Cyclotroning in the presence of C2H4 for up to 40 s, Ni5+ was found to add on a maximum of nine C2H2 ligands. A second “hidden” size‐specific effect was discovered between n = 11 and n = 12, where dehydrogenation intensifies to yield NinC6+ as final products. These are being discussed in terms of close‐packed lattice structures. Finally, the threshold for methane activation by Ni5+ leading to Ni5C+ was determined to be 2.0 ± 0.5 eV.
A cw Laser Absorption Study of the Reactions of Phenyl Radicals with NO, NO2, O2 and Selected Organics Between 298‐404 K
Authors: Preidel M. , Zellner R. 
Published: July 2012

AbstractRate constant for the reactions of phenyl (C6H5) radicals with NO, NO2, O2, C2H4, 2‐butene, benzene, toluene and CCl4 have been determined using a combined laser photolysis/laser absorption technique. Phenyl radicals were generated by 248 nm excimer laser photolysis of C6H5X, where X = Cl, Br and NO. Their temporal behaviour was monitored using cw‐laser line absorption in the X̃2A1‐Ã2B1 transition at 488 nm. At this wavelength the absorption cross section of phenyl has been determined as (9 ± 4) 10−19 cm2. For the rate coefficients of reaction with (1) NO, (2) NO2 and (3) O2 in the temperature range 298‐404 K the following expressions were obtained. magnified image The magnitude of the rate coefficients k1 and k2 and their negative temperature dependence suggest that the reactions between phenyl and NO/NO2 occur as radical recombination and/or (in the case of NO2) as O‐atom metathesis reaction. The apparent low reactivity of phenyl with O2 is likely to be caused by insufficient thermal stability of the phenylperoxy radical. For the reactions of phenyl with selected organics the following upper limits of the rate coefficient at 298 K were determined: k4 (C2H4) ≤ 8 · 10−17 cm3/s; k5 (C2H2) ≤ 8 · 10−16 cm3/s; k6 (2‐butene) ≤ 8 · 10−17 cm3/s; k7 (benzene) ≤ 3 · 10−15 cm3/s; k8 (toluene) ≤ 2 · 10−14 cm3/s and k9 (CCl4) ≤ 1 · 10−15 cm3/s. These limits did not change significantly even around 400 K.
Complex Formation Constants of Nitrate Complexes of Lanthanides and Actinides in the fourth Oxidation State
Authors: Strnad J. , Kohler H.‐H. 
Published: July 2012

AbstractA simple theoretical model is presented for the nitrato complexation of f‐elements in the fourth oxidation state and their precipitation with cationic surfactants. The model is based on the assumption of independent ligand binding sites and applies to solutions with high nitrate concentrations. It is successfully used to describe the precipitation data of hexanitrato complexes of Th(IV), Ce(IV) and U(IV) with hexadecylpyridinium nitrate.
Laser Microdissection in the Search for the Molecular Basis of Diseases A Molecular Library from a Human Chromosome Segment
Authors: Eckelt A. , Ponelies N. , Bautz E. K. F. , Miller K. , Heuer T. , Tümmler B , Grzeschik K. H. , Wolfrum J. , Greulich K. O. 
Published: July 2012

AbstractIt is shown that a UV Laser microbeam can replace mechanical microdissection for the preparation of human chromosome segment specific DNA libraries. 450 DNA fragments are prepared from segment q22‐32 of human chromosome 7. 220 of them are of low copy number. 20 of the clones analyzed by gel electrophoresis have an average molecular weight of 3.8 kb. Three out of a sample of four clones can be localized to chromosome bands 7q22‐q32.
On the Dielectric Relaxation of Aqueous Myoglobin Solutions
Authors: Dachwitz E. , Parak F. , Stockhausen M. 
Published: July 2012

AbstractThe complex permittivity of aqueous myoglobin (Mb) and (for comparison) aqueous polyvinylpyrrolidone (PVP) solutions was measured at 20°C in the frequency range from 2 MHz to 72 GHz. The data were fitted by a sum of Debye type spectral components. For Mb, five terms are needed which are ascribable to the tumbling of the whole Mb molecule (τ1 ≈ 29000 ps) and to free water (τ4 = 10 ps, τ5 = 5 ps). Special attention has been payed to the intermediate region (τ2 ≈ 2500 ps, τ3 ≈ 200 ps for Mb). The comparison of these relaxation times and of the corresponding relaxation strengths with results on PVP shows clearly that the relaxation at about 200 ps is due to bound water while the relaxation in the nanosecond region involves internal motions of the Mb molecule. For the latter, myoglobin is estimated to contribute an appreciable part of the observed squared dipole moment by the independent fluctuation of amide groups and of charges on the residues GLU, ASP, LYS and ARG, where the amplitudes of the motions are taken from the mean square displacements, 〈x2〉, obtained from X‐ray structure analysis.
Space Charge Regions in Solid Two Phase Systems and Their Conduction Contribution. IV: The Behaviour of Minority Charge Carriers Part A: Concentration Profiles, Conductivity Contribution, Determination by Generalized Wagner‐Hebb‐Procedure
Authors: Maier Joachim 
Published: July 2012

AbstractThe concentration profiles of minority charge carriers in ideal space charge regions are calculated. In most cases the space charge potential and thus also the minority carrier profiles are determined by the interface interaction of the majority charge carriers with the neighbouring coexisting phase. The conductivity effects of the minority charge carriers in space charge regions are derived for macro‐ and micro‐sized systems. The important procedure of Wagner‐Hebb‐polarization for determining these quantities is extended for inhomogeneous systems under consideration.
Space Charge Regions in Solid Two Phase Systems and Their Conduction Contribution. IV: The Behaviour of Minority Charge Carriers Part B: Application to the Interfaces AgCl/γ‐Al2O3 and SnO2/O2
Authors: Maier Joachim 
Published: July 2012

AbstractThe analysis of space charge effects on minority charge carriers are applied to two important examples where the electrons are in minority: a) to an ionically conductive system, where the electronic behavior is shown to be a good probe for the interfacial situation and b) to a semiconductive material, where the conduction properties of the minority charge carriers may represent the overall value. In AgCl (a) both the (mean) n‐ and p‐conductivity are found to be enhanced if “heterogeneously doped” by γ‐Al2O3. The separation into bulk and space charge contribution rendered possible by the analysis of Part A (extension of Wagner‐Hebb‐polarization), shows that this surprising result is in quantitative agreement with the interfacial behavior postulated in such composite electrolytes exhibiting enhanced ionic conductivity. The consideration of the SnO2/O2 interface highlights — representative for similar semiconductor systems with appreciably high ionic point defect concentrations — the importance of ionic defect profiles. Findings such as the beneficial effect of halide contamination on the well‐known O2‐sensing properties of SnO2 surfaces as well as “strange” space charge potentials can be explained in a straight‐forward way.
Electrochemically Prepared Insulation for Carbon Fiber Microelectrodes
Authors: Potje‐Kamloth Karin , Janata Jirí , Josowicz Mira 
Published: July 2012

AbstractA new process for encapsulation of electroactive areas of microelectrodes by electropolymerization is described. The major difference from conventional techniques is the ability to fabricate encapsulated microelectrodes inexpensively regardless of their dimensions and shape by the same procedure. The thickness of the coating is controlled by the deposition time. The voltammetric characteristics and the integrity of the insulation have been evaluated and the response time was also measured. — Procedure for preparation of bipolar ultramicroelectrodes has been developed. For that purpose the integral auxiliary electrode was prepared by deposition of a Pt‐layer on the poly(oxyphenylene) insulation. The electrochemical behavior of both electrodes which are separated by the insulation layer was tested separately.
Cryopreservation of platelets using trehalose: The role of membrane phase behavior during freezing
Authors: Gläfke Christiane , Akhoondi Maryam , Oldenhof Harriëtte , Sieme Harald , Wolkers Willem F. 
Published: July 2012

AbstractIn blood banks, platelets are stored at 20–24°C, which limits the maximum time they can be stored. Platelets are chilling sensitive, and they activate when stored at temperatures below 20°C. Cryopreservation could serve as an alternative method for long term storage of platelet concentrates. Recovery rates using dimethyl sulfoxide (DMSO) as cryoprotective agent, however, are low, and removal of DMSO is required before transfusion. In this study, we have explored the use of trehalose for cryopreservation of human platelets while using different cooling rates. Recovery of membrane intact cells and the percentage of nonactivated platelets were used as a measure for survival. In all cases, survival was optimal at intermediate cooling rates of 20°C min−1. Cryopreservation using DMSO resulted in high percentages of activated platelets; namely 54% of the recovered 94%. When using trehalose, 98% of the platelets had intact membranes after freezing and thawing, whereas 76% were not activated. Using Fourier transform infrared spectroscopy, subzero membrane phase behavior of platelets has been studied in the presence of trehalose and DMSO. Furthermore, membrane hydraulic permeability parameters were derived from these data to predict the cell volume response during cooling. Both trehalose and DMSO decrease the activation energy for subzero water transport across cellular membranes. Platelets display a distinct lyotropic membrane phase transition during freezing, irrespective of the presence of cryoprotective agents. We suggest that concomitant uptake of trehalose during freezing could explain the increased survival of platelets cryopreserved with trehalose. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Biotransformation of 2,6‐diaminopurine nucleosides by immobilized Geobacillus stearothermophilus
Authors: De Benedetti Eliana C. , Rivero Cintia W. , Britos Claudia N. , Lozano Mario E. , Trelles Jorge A. 
Published: July 2012

AbstractAn efficient and green bioprocess to obtain 2,6‐diaminopurine nucleosides using thermophilic bacteria is herein reported. Geobacillus stearothermophilus CECT 43 showed a conversion rate of 90 and 83% at 2 h to obtain 2,6‐diaminopurine‐2′‐deoxyriboside and 2,6‐diaminopurine riboside, respectively. The selected biocatalyst was successfully stabilized in an agarose matrix and used to produce up to 23.4 g of 2,6‐diaminopurine‐2′‐deoxyriboside in 240 h of process. These nucleoside analogues can be used as prodrug precursors or in antisense oligonucleotide synthesis. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Genomic analysis of a hybridoma batch cell culture metabolic status in a standard laboratory 5 L bioreactor
Authors: Kondragunta Bhargavi , Han Jing , Joshi Bharat H , Brorson Kurt A. , Puri Raj K. , Uplekar Shaunak , Moreira Antonio R. , Rao Govind 
Published: July 2012

AbstractCurrently, there is a gap in the knowledge of the culture responses to controlled bioreactor environment during the course of batch cell culture from early exponential phase to stationary‐phase. If available, such information could be used to designate gene transcripts for predicting cell status and as a quality predictor for a controlled bioreactor. In this study, we used oligonucleotide microarrays to obtain baseline gene expression profiles during the time‐course of a hybridoma batch cell culture in a 5 L bench‐scale bioreactor. Gene expression changes that were up or down modulated from early‐to‐late in batch culture, as well as invariant gene profiles with significant expression were identified using microarray. Typical cellular functions that seemed to be correlated with transcriptomics were oxidative stress response, DNA damage response, apoptosis, and cellular metabolism. As confirmatory evidence, microarray findings were verified with a more rigorous semiquantitative gene‐specific Reverse transcriptase‐polymerase chain reaction (RT‐PCR). The results of this study suggest that under predefined bioreactor culture conditions, significant gene changes from lag to log to stationary phase could be identified, which could then be used to track the culture state. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
The obliquus capitis inferior myodural bridge
Authors: Pontell Matthew E. , Scali Frank , Marshall Ewarld , Enix Dennis 
Published: July 2012

AbstractThis study was designed to examine the obliquus capitis inferior (OCI) muscle from a gross anatomical perspective. The objective was to isolate and identify the OCI myodural bridge, while examining its course and contributing elements. An earlier study of the posterior cervical spine briefly reported a connection between the OCI and the cervical dura mater. To the best of our knowledge, a study has not yet been conducted specifically on this muscle and its relation to the dura mater. In this study, the suboccipital regions of nine embalmed cadavers were dissected. A total of 14 OCI muscles were isolated for examination. All findings were documented via photograph. Of the 14 OCI muscles isolated, all emitted fibrous tissue bands from the anterolateral portion of the muscular belly. These fibers attached to the posterolateral cervical dura mater by route of the atlantoaxial interspace. The OCI myodural bridge appeared to coalesce with the rectus capitis posterior major myodural bridge, giving the appearance of a single atlantoaxial structure that links these two muscles to the dura mater. In conclusion, the OCI was attached to the dura mater in all of the 14 muscle specimens. We hypothesize that the OCI myodural bridge may play a physiological role in monitoring dural tension and preventing dural infolding. It may also contribute to certain clinical symptoms manifesting from alterations in dural tone. Clin. Anat. 2013. © 2012 Wiley Periodicals, Inc.
Researcher identity: Exploring the transformatory power of the research experience
Authors: Hamilton Kathy , Dunnett Susan , Downey Hilary 
Published: July 2012

ABSTRACTIn consumer research, we frequently focus on the phenomenon of transformation, whether the transformatory effects of a particular consumption community or the great body of work being carried out under the banner of transformative consumer research. However, there is a particular transformation which occurs in the field of interpretivist consumer research that, we would argue, is overlooked—that of researcher transformation. We present as data our reflexive considerations on the ways in which our own research with vulnerable consumers has affected and changed us. We consider short‐term transformations in the field, reflecting on the various ways that researcher identity is carefully managed and negotiated to fit with the social–cultural setting. We also consider longer term transformations and discuss the enduring impact of the research process—the people we have met, the homes we have visited, and the stories we have heard. By reflecting on the shaping of identities ‘in the field’, we aim to deepen our appreciation of the interpretive consumer research process and contribute to theoretical understanding of transformative identity research. Copyright © 2012 John Wiley & Sons, Ltd.
Gas Permeation through Polydimethylsiloxane Membranes: Comparison of Three Model Combinations
Authors: Lin D. , Ding Z. , Liu L. , Ma R. 
Published: July 2012

AbstractThe modeling of a gas mixture permeating through a polymeric membrane can be achieved by the combination of a mass transfer model with a thermodynamic model. In this study, three model combinations, i.e., the combination of Fick's law with Henry's law (F‐H), that of Fick's law with the UNIQUAC equation (F‐U), and that of the Maxwell‐Stefan equation with the UNIQUAC equation (MS‐U), were solved by iteration computer procedure to predict the separation performance of both binary and ternary gas mixtures permeating through a polydimethylsiloxane membrane. The predicted results were analyzed in detail and compared with experimental results. It was found that there are remarkable differences among the considered model combinations in predicting separation performance, and these differences tend to become larger with increasing solubility. Among the three considered model combinations, MS‐U gives the prediction closest to the experimental results. Its advantage over the other two model combinations should be due to the proper estimation of the permeate solubility by the UNIQUAC equation and the reasonable consideration of mass transfer resistance by the Maxwell‐Stefan equation.
[Ru2Bi14Br4](AlCl4)4by Mobilization and Reorganization of Complex Clusters in Ionic Liquids
Authors: Groh Matthias F. , Isaeva Anna , Ruck Michael 
Published: July 2012

AbstractTwo polymorphs of the new cluster compound [Ru2Bi14Br4](AlCl4)4have been synthesized from Bi24Ru3Br20in the Lewis acidic ionic liquid [BMIM]Cl/AlCl3([BMIM]+: 1‐n‐butyl‐3‐methylimidazolium) at 140 °C. A large fragment of the precursor’s structure, namely the [(Bi8)Ru(Bi4Br4)Ru(Bi5)]5+cluster, dissolved as a whole and transformed into a closely related symmetrical [(Bi5)Ru(Bi4Br4)Ru(Bi5)]4+cluster through structural conversion of a coordinating Bi82+to a Bi5+polycation, while the remainder was left intact. Both modifications have monoclinic unit cells that comprise two formula units (α form:P21/n,a=982.8(2),b=1793.2(4),c=1472.0(3) pm,β=109.05(3)°; β form:P21/n,a=1163.8(2),b=1442.7(3),c=1500.7(3),β=97.73(3)°). The [Ru2Bi14Br4]4+cluster can be regarded as a binuclear inorganic complex of two ruthenium(I) cations that are coordinated by terminal Bi5+square pyramids and a central Bi4Br4ring. The presence of a covalent RuRu bond was established by molecular quantum chemical calculations utilizing real‐space bonding indicator ELI‐D. Structural similarity of the new and parent cluster suggests a structural reorganization or an exchange of the bismuth polycations as mechanisms of cluster formation. In this top‐down approach a complex‐structured unit formed at high temperature was made available for low‐temperature use.
Optically Active α‐Phenylethylamine as Efficient Organocatalyst in the Solvent‐free Reactions Between 2,3‐Butanedione and Conjugated Nitroolefins
Authors: Felluga Fulvia , Forzato Cristina , Nitti Patrizia , Pitacco Giuliana , Prati Fabio , Valentin Ennio , Zangrando Ennio 
Published: July 2012

ABSTRACT(R)‐(+) and (S)‐(−)‐1‐phenylethylamine have been shown to promote highly diastereoselective and complementary enantioselective formal [3 + 2]carbocyclization reactions between 2,3‐butanedione and conjugated nitroalkenes with formation of enantiomerically rich 2‐hydroxy‐3‐nitrocyclopentanone derivatives. The reactions were carried out both in solvent and under solvent‐free conditions. The absolute configurations of the products were assigned by X‐ray and circular dichroism spectra analyses. Chirality 24:1005–1012, 2012. © 2012 Wiley Periodicals, Inc.
Photocatalytic Decolorization Kinetics and Mineralization of Reactive Black 5 Aqueous Solution by UV/TiO2 Nanoparticles
Authors: Sharma Sandeep Kumar , Bhunia Haripada , Bajpai Pramod Kumar 
Published: July 2012

AbstractThe photocatalytic decolorization and mineralization of Reactive Black 5 (RB5) dye in presence of TiO2 Degussa P25 has been studied using artificial light radiation in a shallow pond slurry reactor. The equilibrium adsorption of dye, influence of pH (3–11), catalyst load (0.5–3.0 g/L), and dye concentration (20–100 mg/L) on decolorization kinetics were studied. The effect of area to volume ratio of photoreactor on decolorization kinetics has been also studied. Mineralization studies were performed at optimized conditions of pH (3) and catalyst load (1.5 g/L). The maximum adsorption (26.5 mg/g) of dye was found to occur at pH 3. The apparent pseudo first order decolorization rate constant (kapp) value followed the order pH 3 > pH 11 > pH 9 > pH 7. As compared to available literature reduction in total organic carbon (TOC) was minimal by the time there was complete decolorization. Initial reduction in TOC was followed by subsequent increasing trend till complete decolorization. Final decreasing trend in TOC was observed only after complete decolorization. Twelve hours of treatment under experimental conditions reduced TOC content by 70% only. Discussion of results suggest that photocatalytic treatment of colored effluent under low UV intensity, and low A/V ratio may result in completely decolorized effluent but still having high COD.
Treatment of Domestic Sewage in an Anaerobic–Aerobic Fixed‐bed Reactor with Recirculation of the Liquid Phase
Authors: de Oliveira Netto Antonio Pedro , Zaiat Marcelo 
Published: July 2012

AbstractThis study reports the performance of a combined anaerobic–aerobic packed‐bed reactor that can be used to treat domestic sewage. Initially, a bench‐scale reactor was operated in three experimental phases. In the first phase, the anaerobic reactor was operated with an average organic matter removal efficiency of 77% for a hydraulic retention time (HRT) of 10 h. In the second phase, the reactor was operated with an anaerobic stage followed by an aerobic zone, resulting in a mean value of 91% efficiency. In the third and final phase, the anaerobic–aerobic reactor was operated with recirculation of the effluent of the reactor through the anaerobic zone. The system yielded mean total nitrogen removal percentages of 65 and 75% for recycle ratios (r) of 0.5 and 1.5, respectively, and the chemical oxygen demand (COD) removal efficiencies were higher than 90%. When the pilot‐scale reactor was operated with an HRT of 12 h and r values of 1.5 and 3.0, its performance was similar to that observed in the bench‐scale unit (92% COD removal for r = 3.0). However, the nitrogen removal was lower (55% N removal for r = 3.0) due to problems with the hydrodynamics in the aerobic zone. The anaerobic–aerobic fixed‐bed reactor with recirculation of the liquid phase allows for concomitant carbon and nitrogen removal without adding an exogenous source of electron donors and without requiring any additional alkalinity supplementation.