bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequence Similarity and Cross‐Reactivity of a Diels–Alder Catalyst and an Anti‐Progesterone Antibody
Authors: Haynes Matthew R. , Lenz Martin , Taussig Michael J. , Wilson Ian A. , Hilvert Donald 
Published: November 2013

AbstractAntibody 1E9 catalyzes the bimolecular Diels–Alder reaction between tetrachlorothiophene dioxide and N‐ethylmaleimide with high catalytic efficiency. The genes encoding the heavy and light chains were cloned, sequenced, and expressed as a mouse/human chimera in a murine hybridoma. Comparison with the closely related and structurally characterized anti‐progesterone antibody DB3 has permitted identification of the residues that are likely to line the binding cavity. In addition to confirming the expectation of a highly hydrophobic active site, modeling results suggest that shape complementarity, achieved mainly through van der Waals rather than hydrogen bonding or electrostatic interactions, is likely to be the dominant factor in achieving effective preorganization of the substrates for catalysis. These conclusions can now be investigated through targeted mutagenesis of the putative active site residues exploiting the mammalian expression system.
Electric Field Measurements inside Self‐Assembled Multilayer Films at Electrode Surfaces by Electrochemically Modulated Surface Plasmon Resonance Experiments
Authors: Hanken Dennis G. , Corn Robert M. 
Published: November 2013

AbstractThe new in situ optical technique of electrochemically modulated surface plasmon resonance (EM‐SPR) is described and applied to the measurement of the electrostatic fields inside noncentrosymmetric zirconium phosphonate (ZP) films formed from the asymmetric nonlinear optical material [1‐[4‐[4‐[(N‐(2‐hydroxyethyl)‐N‐methyl)amino]phenyl]azo](5‐phosphonopentyl)] pyridinium bromide (PY‐AZO). In situ EM‐SPR measurements on PY‐AZO films yield a value for the change in electric field strength (ΔE) of 4 × 103 V/cm for a change in electrode potential (Δϕm) at 0.0 V vs. SCE of ±25 mV (8 × 104 V/cm for Δϕm = 1 V). This electric field strength value indicates that there is substantial ion penetration into the film in the electrochemical environment. Both the phase and magnitude of the surface optical response in the EM‐SPR measurements are used to distinguish the molecular and metal electrode contributions to the overall optical signal. These two EM‐SPR contributions are identified and separated in a quantitative fashion through a series of theoretical Fresnel calculations.
Adsorption of Some Atmospherically Important Molecules onto Large Water Clusters: SO2, SO3, HCl, and ClONO2
Authors: Apps C.J. , Watt N.E. , Whitehead J.C. 
Published: November 2013

AbstractThe adsorption of a range of atmospherically important molecules (SO2, SO3, HCl, and ClONO2) on large water clusters have been studied using a supersonic molecular beam expansion to generate water clusters containing 50–450 water molecules. SO2 and HCl were found to stick with low efficiency to the water cluster, retaining their chemical identity. In contrast, both SO3 and ClONO2 undergo heterogeneous reactions on the surface of the water cluster forming, respectively, H2SO4 and HOCl with HNO3. For SO3, calculations show that the large barrier that exists in the gas‐phase to the reaction of SO3 with water is removed for water clusters of a sufficient size because of stabilization of the transition state by solvation. For ClONO2, the barrier to reaction is much larger and cannot be removed by solvation for any size cluster. In this case, it is likely that reaction takes place on the water cluster by the ionic dissociation of ClONO2 in a similar manner to that observed for ClONO2 on ice films.
CVD Diamond Wafers Fabricated by DC Arc Jet
Authors: Windischmann Henry , Simpson Matthew A. 
Published: November 2013

AbstractAs the clock speed and chip power density continue to increase, heat management is becoming an ever‐increasing challenge for package designers. In addition, the demand for a narrow profile in consumer products and compact footprint may disqualify traditional heat dissipation materials as viable solutions. Diamond is a premier candidate for this application because of its unmatched thermal conductivity and low density. However, the outstanding issue is cost and availability. This paper discusses dc arc jet deposition technology and the stress issues that must be addressed to develop a reliable fabrication process. By adopting tight process control and matching the substrate's thermal properties to the film, a crack‐free 175‐mm‐diameter diamond wafer fabrication process has been developed with uniform properties and wafer yields that exceed 90% for thicknesses greater than 200 μm.
Growth and Adhesion Enhancement of Diamond Films Deposited on Steel Substrates by a Cr–N Interlayer
Authors: Glozman Olga , Hoffman Alon 
Published: November 2013

AbstractDiamond film deposition onto iron‐based substrates by chemical vapor deposition methods is complicated by the formation of black carbon or graphitic soot on the substrate surface prior to diamond nucleation and growth, by fast diffusion of carbon into the iron substrate, and by poor adhesion of the deposited film. These complications suggested the use of a buffer layer between the deposited diamond film and the iron‐based substrate. We review different methods used to improve the adhesion of diamond film to steel substrates. In particular we describe in detail our own studies which involve the use of a Cr‐N interlayer. The use of a chromium nitride interlayer has been found to improve significantly the adhesion of diamond films deposited on ferrous substrates. This is achieved by hindering diffusion processes of carbon and iron, very stable mechanical and chemical bonding between the interlayer and the diamond film, and good adhesion of the interlayer to the steel substrate. We also report on our studies related to residual stress present in the films, as well as a correlation between the interlayer properties and adhesion strength of deposited films.
Diamond‐Coated WC–Co Cutting Tools
Authors: Inspector Aaron , Bauer C. Erik , Gates Alfred S. , Oles Edward J. 
Published: November 2013

AbstractThe unique combination of high hardness, high thermal conductivity, and low friction coefficient makes diamond an excellent cutting tool material for the machining of abrasive, non‐ferrous workpieces. This paper reviews basic and applied aspects of the technology as applied to the preparation of diamond coated cutting tools.
Homoepitaxial Diamond Devices
Authors: Fox Bradley A. , Dreifus David L. 
Published: November 2013

AbstractDiamond has been proposed as an excellent material for high‐temperature, high‐power, and high‐frequency applications. The interest in diamond electronics is due to its large electric breakdown field, high‐saturated current velocity and high‐thermal conductivity. As silicon and gallium arsenide devices begin to reach their performance limits, there is a need to develop new, better performing materials such as diamond. Significant progress in the development of diamond as a semiconducting material has been made and diamond has been implemented into numerous conventional and novel device designs. In this work homoepitaxial diamond material properties and device performance are reviewed. In summary, the large activation energy of boron‐doped p‐type diamond and phosphorus‐doped n‐type diamond severely limits diamond's use in conventional semiconductor device designs. The large activation energy reduces the number of charge carriers, which limits the current handling capability and produces temperature‐dependent device performance. To overcome diamond's limitations, novel devices, such as enhancement mode field effect transistors (FETs) that use a hydrogenated surface conducting layer or pulsed doped devices with almost complete ionization, have been investigated. These devices require further development. The initial results show promise for high‐temperature, high‐frequency, and high‐power applications.
Devices at High Temperatures—Status and Prospects
Authors: Kohn Erhard , Ebert Wolfgang , Vescan Andrei 
Published: November 2013

AbstractThe temperature‐handling capability of diamond diode and field effect transistor structures is discussed and compared with recent results on GaN. The main parameters limiting the high‐temperature performance are identified and evaluated. A diamond high‐temperature technology is presented which has allowed 1000°C operation of a diamond Schottky diode, the highest temperature of operation of any semiconductor diode yet.
Laser Studies of Small Radicals in Rich Methane Flames: OH, HCO, and 1CH2
Authors: McIlroy Andrew 
Published: November 2013

AbstractChemical mechanisms for combustion processes are often developed for nearly stoichiometric flames, a perfect balance of fuel and oxidizer. As the fuel content is increased and flames become richer, these models will eventually break down because they lack reactions leading to the formation of larger hydrocarbons and ultimately soot. In this contribution, we investigate the behavior of two methane combustion models, the GRI 2.11 and Prada–Miller mechanisms, in a series of rich flames of stoichiometry 1.0, 1.2, 1.4, and 1.6. Using non‐intrusive laser diagnostics, laser‐induced fluorescence, and cavity ring‐down spectroscopy, the concentration profiles as a function of height above burner for OH, HCO, and 1CH2 have been measured in these rich low‐pressure methane flames. The experimental results are compared to the calculated profiles. In general, good agreement is found for all species over the range of stoichiometries investigated. The agreement of the OH and HCO profiles with the models is particularly striking. For 1CH2, the width, position, and relative height of the profiles match the model predictions for flames of stoichiometry 1.0 and 1.2. Discrepancies are noted for the richer flames investigated, those with stoichiometrics of 1.4 and 1.6. An analysis of the models suggests that additional pathways for 1CH2 formation and removal should be considered. Even under fairly rich conditions, stoichiometry of 1.6, both models perform well for the radicals investigated here. There is no indication of the requirement for >C2 chemistry to reproduce the present data.
Experimental and Numerical Study of the Effect of an Electric Field on a Bunsen‐type Flame
Authors: Hu Jing , Rivin Boris , Sher Eran 
Published: November 2013

AbstractThe effect of an electric field on the behavior of premixed methane‐air flames has been studied. A candle‐type flame has been observed experimentally and analyzed for its geometrical proportions under an electric field. A numerical model has been developed to explain some of the experimental observations. The model employs a two‐dimensional cylindrical coordinate system and assumes axial symmetry. The mass, momentum, species, and energy conservation equations are solved by an integrated version of the PHOENICS and CHEMKIN computer codes. It is concluded that the effect of the electric field on the flame behavior is mainly due to ionic wind effects.
Temperature Dependence of Excited‐State Proton Transfer and Geminate Recombination Processes in Water and in Glycerol‐Doped Ice
Authors: Poles Ehud , Cohen Boiko , Huppert Dan 
Published: November 2013

AbstractThe reversible proton dissociation and geminate recombination of photoacids was studied as a function of temperature in neat water, binary water mixture containing 0.6 mol% glycerol, and doped ice containing 0.6 mol% glycerol. The deuterium isotope effect on both condensed phases was also studied. 8‐hydroxypyrene‐1,3,6 trisulfonate trisodium salt was used as the electronically‐excited‐state proton emitter. The experimental data are analyzed by the Debye–Smoluchowski equation solved numerically with boundary conditions to account for the reversibility of the reaction. We propose a qualitative model to describe the unusual temperature dependence of the proton transfer rate in the liquid phase. We also propose a model for proton transfer in solid ice based on L‐defects transport as proton acceptors. While in the liquid phase at t > 10°C the proton dissociation rate constant is almost temperature independent, in glycerol‐doped ice we find a large temperature dependence.
Ground‐ and Excited‐State Proton Transfer in Some o‐Hydroxy Aromatic Compounds and Solvent Effect
Authors: Guha Dipanwita , Mandal Abhijit , Das Ranjan , Mitra Sivaprasad , Mukherjee Samaresh 
Published: November 2013

AbstractProton transfer reaction in the ground and excited state of 4‐methyl‐2,6‐diformyl phenol (MFOH) and some of its derivatives in different nonpolar and polar solvents has been studied using steady‐state and nanosecond transient emission spectroscopy at room temperature and 77 K. The stable molecular structure in the ground state is an intramolecularly hydrogen‐bonded closed conformer from which the intramolecular proton transfer (ESIPT) takes place in the first excited singlet state in nonpolar solvents. An emission band originates from the proton‐transferred enol tautomer of the closed conformer. From a detailed study of the absorption, emission, and excitation spectra in highly polar protic and aprotic solvents, two other conformers have been identified. At 77 K in nonpolar solvents, emission spectra show phosphorescence only in the case of MFOH and 4‐methyl‐2,6‐diamidophenol (MDOH). In the case of other derivatives, such as 4‐methyl‐2,6‐diacetylphenol (MAOH) and 4‐methyl‐2,6‐dicarbomethoxyphenol (MOOH), phosphorescence is observed only in the presence of a strong base, such as trimethylamine. This conversion of fluorescence into phosphorescence is markedly slow in the case of MDOH, MAOH, and MOOH compared to that of MFOH. The relatively larger values of fluorescence lifetimes at 77 K are consistent with our observation. It is proposed that the occurrence of phosphorescence is from an open conformer and is caused by the rotation of the formyl group. From nanosecond measurements and quantum yields of fluorescence, we have estimated the decay rate constants. The fluorescence decay rates are slower in polar than in nonpolar solvents; nonradiative decay rates are always found to be dominant over the radiative ones.
Proton Solvation and Proton Mobility
Authors: Agmon Noam 
Published: November 2013

AbstractExperimental evidence for proton solvation and proton mobility is analyzed and the results are compared with recent simulations. Three factors contribute to differences in proton solvation energies: hydrogen‐bond cleavage, changes in hydrogen‐bond lengths, and proton derealization. These factors are estimated from experimental attributes. In dilute acidic aqueous solutions H3O+ is more stable than H5O2+ by about 0.6 kcal/mol. This estimate, together with the activation energy for proton mobility, supports the 121 mechanism for proton mobility in which a protonated water monomer is transformed, by second‐shell hydrogen‐bond cleavage, to a protonated dimer and back to another protonated monomer.
Electronic properties of anodized TiO2 electrodes and the effect on in vitro response
Authors: Löberg Johanna , Gretzer Christina , Mattisson Ingela , Ahlberg Elisabet 
Published: November 2013

AbstractFor dental implants, improved osseointegration is obtained by modifying the surface roughness as well as oxide morphology and composition. A combination of different effects contributes to enhanced performance, but with surface roughness as the dominant factor. To single out the effect of oxide conductivity on biological response, oxide films with similar thickness and surface roughness but different electronic properties were formed using galvanostatic anodization. Three different current densities were used, 2.4, 4.8, and 11.9 mA cm−2, which resulted in growth rates ranging from 0.2 to 2.5 V s−1. The electronic properties were evaluated using cyclic voltammetry and impedance spectroscopy, while the biological response was studied by cell activity and apatite formation. The number of charge carrier in the oxide film close to the oxide/solution interface decreased from 5.8 × 10−19 to 3.2 × 10−19 cm−2 with increasing growth rate, that is, the conductivity decreased correspondingly. Cell response of the different surfaces was tested in vitro using human osteoblast‐like cells (MG‐63). The results clearly show decreased osteoblast proliferation and adhesion but higher mineralization activity for the oxide with lower conductivity at the oxide/solution interface. The apatite‐forming ability was examined by immersion in simulated body fluid. At short times the apatite coverage was ∼26% for the anodized surfaces, significantly larger than for the reference with only 3% coverage. After 1 week of immersion the apatite coverage ranged from 73 to 56% and a slight differentiation between the anodized surfaces was obtained with less apatite formation on the surface with lower conductivity, in line with the cell culture results. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 826–839, 2014.
Effects of sterilization methods on the physical, chemical, and biological properties of silk fibroin membranes
Authors: de Moraes Mariana Agostini , Weska Raquel Farias , Beppu Marisa Masumi 
Published: November 2013

AbstractSilk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physical, chemical, and biological characteristics of dense and porous silk fibroin membranes. Silk fibroin membranes were treated by several procedures: immersion in 70% ethanol solution, ultraviolet radiation, autoclave, ethylene oxide, and gamma radiation, and were analyzed by scanning electron microscopy, Fourier‐transformed infrared spectroscopy (FTIR), X‐ray diffraction, tensile strength and in vitro cytotoxicity to Chinese hamster ovary cells. The results indicated that the sterilization methods did not cause perceivable morphological changes in the membranes and the membranes were not toxic to cells. The sterilization methods that used organic solvent or an increased humidity and/or temperature (70% ethanol, autoclave, and ethylene oxide) increased the silk II content in the membranes: the dense membranes became more brittle, while the porous membranes showed increased strength at break. Membranes that underwent sterilization by UV and gamma radiation presented properties similar to the nonsterilized membranes, mainly for tensile strength and FTIR results. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 869–876, 2014.
Kinetics of Fading of Some Triphenylmethane Dyes: Effects of Electric Charge, Substituent, and Aqueous Binary Mixtures of Dimethyl Sulfoxide and 2‐Propanol
Authors: Samiey B. , Dalvand Z. 
Published: November 2013

ABSTRACTThe rate constants of alkaline fading of a number of triphenylmethane (TPM) dyes including methyl green (ME2+), brilliant green (BG+), fuchsin acid (FA2−), and bromophenol blue (BPB2−) were obtained in aqueous binary mixtures of 2‐propanol (protic solvent) and dimethyl sulfoxide (DMSO) (aprotic solvent) at different temperatures. It was observed that the reaction rate constants of BG+ and ME2+ increased and those of FA2− and BPB2− decreased with an increase in weight percentages of aqueous 2‐propanol and DMSO binary mixtures. 2‐Propanol and DMSO interact with the used TPM molecules through hydrogen bonding and ion–dipole interaction, respectively, in addition to their hydrophobic interaction with TPM dyes. The fundamental rate constants of a fading reaction in these solutions were obtained by the SESMORTAC model. Also, the effect of electric charge and substituent groups of a number of TPM dyes on their alkaline fading rate was studied.
Improved voluntary cough immediately following office‐based vocal fold medialization injections
Authors: Ruddy Bari H. , Pitts Teresa E. , Lehman Jeff , Spector Brian , Lewis Vicki , Sapienza Christine M. 
Published: November 2013

Objectives/HypothesisThis study examined changes in voluntary cough airflow measures immediately following in‐office injection of Radiesse in patients diagnosed with glottic insufficiency. Due to significant comorbidities, these patients were poor candidates for medialization under general anesthesia. Each patient presented with dysphonia and dysphagia and ineffective voluntary cough, resulting in a poor clearing of secretions and a presence of ingested fluids on examination.Study DesignProspective cohort and case series study.MethodsThree patients with a diagnosis of glottic insufficiency were included for study based on flexible endoscopy and laryngostroboscopic examination. Voluntary cough airflow measures were obtained approximately 30 minutes before and after the Radiesse injections. The airflow measures were: compression phase duration (CPD), expiratory rise time (EPRT), expiratory phase peak airflow (EPPF), and cough volume acceleration (CVA).ResultsInjection of Radiesse was found to improve voluntary cough airflow measures.ConclusionThe immediate increase in the objective airflow measures obtained from voluntary cough production after Radiesse injections can be used to document airway protection improvements. Cough airflow is a straightforward measure to obtain and is considered an objective measure of cough function.Level of Evidence4. Laryngoscope, 124:1645–1647, 2014
Tagging & Tracking und Kollisionsprävention im Untertagebergbau
Authors: Becker Franz 
Published: November 2013

AbstractBei der Anwendung von Tagging & Tracking (T&T) im Untertagebergbau werden alle Bergleute, Fahrzeuge, Transportbehälter und Betriebsmittel mit einem codierten RFID‐Baustein, dem sogenannten Tag, ausgerüstet. Sein Code kann von im Bergwerk verteilten Lesegeräten empfangen werden, die in das bergwerksweite Datenübertragungsnetz eingebunden sind. Neben der Disposition von Personen, Fahrzeugen und Material liegen die Hauptaufgaben aktueller T&T‐Systeme bei sicherheitlichen Funktionen wie der Ortung von Personen nach Unfällen. Die Komponenten eines weltweit eingesetzten T&T‐Systems werden vorgestellt.Ferner befasst sich der Beitrag mit Aufbau und Funktionsweise eines neuentwickelten Systems zur Vermeidung von Kollisionen zwischen Fahrzeugen und Bergleuten sowie von Fahrzeugen untereinander. Für diesen Zweck wurde die UHF‐Technologie, die für das T&T‐System genutzt wird, um zwei weitere elektromagnetische Verfahren zur Verbesserung der Umfelderkennung erweitert. Über den Aufbau des Kollisionsschutzsystems und erste Erfahrungen im Bergbau wird berichtet.Tagging & Tracking and collision avoidance in underground mining.When Tagging & Tracking (T&T) is used in underground mining, all miners, vehicles and transport containers or equipment be tracked in the mine workings are provided with a coded RFID module, the so‐called tag. Its code can be received by readers distributed in the mine which are integrated in a mine wide communication network. Alongside vehicle, personnel and material scheduling, the main tasks for current T&T systems in underground mining are safety functions such as locating persons after accidents and risk warnings. The components of a T&T system used globally and applications in international mining shall be introduced in this presentation.It also deals with the design and functions of a newly developed concept to avoid collisions between vehicles and miners and to prevent vehicles colliding. For this purpose the UHF technology which is used for the T&T‐system has been supplemented with two additional electromagnetic processes to improve environment detection. The design of the collision protection system and its technologies are explained and initial experiences with use in mining are reported.