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1

Admittances characterizing a partially filled rectangular waveguide with holes in its side face  

Microsoft Academic Search

Admittances characterizing a partially filled rectangular waveguide with holes in its side face have been determined. Sections\\u000a of such waveguides are elements of complex waveguide connections that are used to construct microwave digital telecommunications\\u000a circuits built on rectangular waveguides partially filled with dielectric. Such admittances include transformation ratios\\u000a that were determined in this study by two different techniques: by way

V. N. Pochernyaev

2007-01-01

2

Microcomputer-based instrumentation for multi-frequency Fourier transform alternating current (admittance and impedance) voltammetry  

Microsoft Academic Search

Microcomputer-based instrumentation has been developed which enables high quality Fourier transform alternating current admittance and impedance voltammograms to be obtained over a wide range of frequencies and d.c. potentials. A carefully chosen phase-optimised small amplitude alternating potential waveform containing sets of frequencies which avoid harmonic or intermodular interference are periodically superimposed onto a staircase d.c. ramped voltage. Considerable versatility is

Jeno Házì; Darrell M. Elton; W. Alexander Czerwinski; Jörg Schiewe; Victoria A. Vicente-Beckett; Alan M. Bond

1997-01-01

3

Implementing transformer nodal admittance matrices into backward\\/forward sweep-based power flow analysis for unbalanced radial distribution systems  

Microsoft Academic Search

This paper proposes a new method to handle distribution transformers of various winding connections in the backward\\/forward sweep-based power flow analysis for unbalanced radial distribution systems. The method takes advantage of available nodal admittance matrices of distribution transformers, and can automatically solve the problem of conductively isolated subnetworks to obtain their equivalent phase-to-reference voltages. In addition, this paper presents a

Zhuding Wang; Fen Chen; Jingui Li

2004-01-01

4

Tevatron admittance measurement  

SciTech Connect

We measured the Tevatron beam admittance by the means of exciting the beam with noise and causing emittance growth. The noise power was about 3W with a bandwidth of 100Hz and centered either in the horizontal betatron frequency or vertical betatron frequency. We were able to controllably blow the beam emittance up quickly. From the point where the beam emittance stopped growing, we measured the beam acceptance of the Tevatron.

Zhang, X.L.; Shiltsev, V.; Tan, C.Y.; /Fermilab

2005-05-01

5

Pulse transformer characterization  

NASA Astrophysics Data System (ADS)

The pulse transformer at TNO PML-Pulse Physics, Delft, is characterized. It constitutes the final step of an energy compression system (Kapitza facility) which can amplify the current up to 24 times, and consists of a primary single layer winding of 24 turns enclosed in a secondary winding. There is a sine wave current source with adjustable frequencies for the characterization. The measurements show that the main inductances decrease and the ohmic resistances increase with increasing frequency, due to differential currents, skin and proximity effect, and parasitic currents induced in the aluminum secondary winding. From the measurements a coupling factor of 0.94 is calculated for 200 Hz, which is slightly below the design specification of 0.98.

Mosterdijk, W. H. P.

1992-12-01

6

Effective admittivity of biological tissues as a coefficient of elliptic PDE.  

PubMed

The electrical properties of biological tissues can be described by a complex tensor comprising a simple expression of the effective admittivity. The effective admittivities of biological tissues depend on scale, applied frequency, proportions of extra- and intracellular fluids, and membrane structures. The effective admittivity spectra of biological tissue can be used as a means of characterizing tissue structural information relating to the biological cell suspensions, and therefore measuring the frequency-dependent effective conductivity is important for understanding tissue's physiological conditions and structure. Although the concept of effective admittivity has been used widely, it seems that its precise definition has been overlooked. We consider how we can determine the effective admittivity for a cube-shaped object with several different biologically relevant compositions. These precise definitions of effective admittivity may suggest the ways of measuring it from boundary current and voltage data. As in the homogenization theory, the effective admittivity can be computed from pointwise admittivity by solving Maxwell equations. We compute the effective admittivity of simple models as a function of frequency to obtain Maxwell-Wagner interface effects and Debye relaxation starting from mathematical formulations. Finally, layer potentials are used to obtain the Maxwell-Wagner-Fricke expression for a dilute suspension of ellipses and membrane-covered spheres. PMID:23710251

Seo, Jin Keun; Bera, Tushar Kanti; Kwon, Hyeuknam; Sadleir, Rosalind

2013-04-16

7

External impedance and admittance of buried horizontal wires for transient studies using transmission line analysis  

Microsoft Academic Search

The paper investigates the applicability of some closed form expressions for the ground impedance and ground admittance of buried horizontal wires (bare and insulated) for lightning or switching transient analyses based on transmission line (TL) theory. In view of the frequency contents that typically characterize such transients, the behavior of the ground impedance and admittance is studied for a wide

Nelson Theethayi; Rajeev Thottappillil; Mario Paolone; Carlo Alberto Nucci; Farhad Rachidi

2007-01-01

8

Applications of Admittance Spectroscopy in Photovoltaic Devices Beyond Majority Carrier Trapping Defects: Preprint  

SciTech Connect

Admittance spectroscopy is commonly used to characterize majority-carrier trapping defects. In today's practical photovoltaic devices, however, a number of other physical mechanisms may contribute to the admittance measurement and interfere with the data interpretation. Such challenges arise due to the violation of basic assumptions of conventional admittance spectroscopy such as single-junction, ohmic contact, highly conductive absorbers, and measurement in reverse bias. We exploit such violations to devise admittance spectroscopy-based methods for studying the respective origins of 'interference': majority-carrier mobility, non-ohmic contact potential barrier, minority-carrier inversion at hetero-interface, and minority-carrier lifetime in a device environment. These methods are applied to a variety of photovoltaic technologies: CdTe, Cu(In,Ga)Se2, Si HIT cells, and organic photovoltaic materials.

Li, J. V.; Crandall, R. S.; Repins, I. L.; Nardes, A. M.; Levi, D. H.; Sulima, O.

2011-07-01

9

Validation of a screening oto- admittance instrument.  

PubMed

A within-subject comparison between an American Electromedics 85R screening tympanometer and a Grason-Stadler 1723 clinical otoadmittance meter indicated equivalent results for middle-ear pressure. Tympanometer admittance readings needed to be rescaled to concur with the oto-admittance meter. Screening by acoustic reflex response using the single-intensity stimulus of the tympanometer was problematic and gave many misleading results. PMID:7159796

Wood, E J; Lutman, M E; Fernandes, M A

1982-11-01

10

How to measure the strength of the lithosphere without using the admittance or coherence between gravity and topography  

NASA Astrophysics Data System (ADS)

The lithosphere is modeled using a differential equation. As such it is characterized by a set of parameters, at least one of which, under the assumption of elastic behavior, is generally thought of as a proxy for its strength: the flexural rigidity (D), or, by extension, the elastic thickness. This lithospheric 'system' then takes an input: topographic loading by mountain building and other processes, and maps it into an output: the gravity anomaly and the final, measurable, topography. The input is not measurable but some of its properties can be characterized. The outputs are measurable but the relation between them is obfuscated by their stochastic nature and the presence of unmodeled components (such as non-linearity, non-elasticity, non-stationarity etc). Estimating D, most usually in the spectral domain, generally involves an exercise in constructing summaries of gravity and topography. Both admittance and coherence are popular; both are ratios of the cross-spectral density of gravity and topography to the power spectral densities of either, the whole sometimes squared. Despite the fact that neither admittance nor coherence have a Gaussian distribution, estimating D usually comes down to the least-squares fitting of a parameterized curve to the non-Gaussian data, where Gaussian behavior is tacitly, but still incorrectly, assumed. In this two-step procedure, admittance or coherence are first estimated, usually aided by tapering of the spatial input data prior to Fourier transforming (which introduces bias but lowers the estimation variance), and subsequently inverted for the strength parameters. Rarely, if ever, are lithospheric models found that satisfy both coherence and admittance to within their true error. This has led to much handwringing in the literature, ever since the methods were introduced in the eighties. Yet, if models of the lithosphere are 'true', and 'fit' the data, they should fit both representations, i.e. both statistics of it. Why don't they? Poorly characterized errors of admittance and coherence are not the only problems with this procedure. There is also the implicit annihilation of information during the construction of these 'statistics' (coarsely sampled, sometimes squared, ratios, measures of the data as they are) themselves. Then there is the fact that we do not want to know coherence and admittance at all - we want to know properties of the lithosphere! In this presentation, we intend to abandon coherence and admittance studies for good, by proposing an entirely different method of estimating flexural rigidity, which returns it and its confidence interval, as well as a host of tests for the suitability of the assumptions made along the way, and the possible presence of correlated loads and anisotropy in the response. The crux of the method is that it employs a maximum-likelihood formulation that remains very grounded in the data themselves, and which is formulated in terms of variables that do have a Gaussian distribution.

Simons, Frederik J.; Olhede, Sofia C.

2010-05-01

11

Structures that Contribute to Middle-Ear Admittance in Chinchilla  

PubMed Central

We describe measurements of middle-ear input admittance in chinchillas (Chinchilla lanigera) before and after various manipulations that define the contributions of different middle-ear components to function. The chinchilla’s middle-ear air spaces have a large effect on the low-frequency compliance of the middle ear, and removing the influences of these spaces reveals a highly admittant tympanic membrane and ossicular chain. Measurements of the admittance of the air spaces reveal that the high-degree of segmentation of these spaces has only a small effect on the admittance. Draining the cochlea further increases the middle-ear admittance at low frequencies and removes a low-frequency (less than 300 Hz) level dependence in the admittance. Spontaneous or sound-driven contractions of the middle-ear muscles in deeply anesthetized animals were associated with significant changes in middle-ear admittance.

Rosowski, John J.; Ravicz, Michael E.; Songer, Jocelyn E.

2009-01-01

12

Direct identification offlutter derivatives and aerodynamic admittances ofbridge decks  

Microsoft Academic Search

Flutter derivatives and aerodynamic admittances provide basis ofpredicting the critical wind speed in flutter and buffeting analysis oflong-span cable-supported bridges. In this paper, one popular stochastic system identification technique, covariance- driven stochastic subspace identification (SSI in short), is first presented for estimation of the flutter derivatives and aerodynamic admittances ofbridge decks f rom their random responses in turbulent flow. Numerical

Ming Gu; Xian-Rong Qin

2004-01-01

13

A new aperture admittance model for open-ended waveguides  

Microsoft Academic Search

A new model for the aperture admittance of open-ended waveguide structures radiating into a homogeneous, lossy dielectric is presented. The model is based on the physical and mathematical properties of the driving point admittance of passive, stable one-port networks. The model parameters, which depend upon the geometry of the waveguide and aperture, are determined from a relatively small number of

S. S. Stuchly; C. L. Sibbald; J. M. Anderson

1994-01-01

14

Haptic Rendering of Actuated Mechanisms by Active Admittance Control  

Microsoft Academic Search

Virtual Prototyping with haptic feedback offers great bene- fits in the development process of actuated systems. We present a generic control scheme for the haptic rendering of actuated mechanisms, intro- ducing the active admittance. It extends the conventional admittance control by modeling the actuation and the movable parts of the mecha- nism separately. This allows for an efficient iterative design

Michael Strolz; Martin Buss

2008-01-01

15

Experimental Demonstration of the Grasp Admittance Center Concept  

Microsoft Academic Search

This paper demonstrates a new approach to achieving decoupled dynamic behavior in multifingered robotic hands. The approach is based on a new concept termed the Grasp Admittance Center. This concept is a generalized version of the Compliance Center concept, well known within the robotics literature for over a decade. The proposed admittance center concept provides a framework for simultaneously achieving

A. A. Goldenberg; K. B. Shimoga

1993-01-01

16

Characterization Of Signals By The Ridges Of Their Wavelet Transforms  

Microsoft Academic Search

Many procedures have been developed to characterize a signal by some of the salientfeatures of a specific transform, whether it is the Fourier, the Gabor, the Wigner ormore recently the wavelet transform. Ridges in the modulus of the transform determineregions in the transform domain with a high concentration of energy. For this reasonthey are regarded as natural candidates for the

René A. Carmona; Wen L. Hwang; Bruno Torrésani

1995-01-01

17

Characterization of coreless printed circuit board (PCB) transformers  

Microsoft Academic Search

In this paper, coreless printed-circuit-board transformers are characterized. A range of coreless printed circuit board (PCB) transformers with different geometric parameters have been fabricated and tested. Based on a recently reported analytic method, the self inductance of these transformers is calculated. This analytical method is also extended to cover the prediction of the transformers' mutual inductance. All calculated parameters have

S. C. Tang; S. Y. Hui; H. S.-H. Chung

2000-01-01

18

Series expansion of the quantum admittance in mesoscopic systems  

NASA Astrophysics Data System (ADS)

The quantum admittance of an interacting/coupled mesoscopic system and its series expansion are obtained by using the refermionization method. With the help of these nonperturbative results, it is possible to study the dependencies of the admittance according to the applied dc voltage, temperature, and frequency without any restriction on the relative values of these variables. Explicit expressions of the admittance are derived both in the limits of weak and strong interactions/coupling strength, giving clear indication of the inductive or capacitive nature of the mesoscopic system. They help to determine the conditions under which the phase of the current with respect to the ac voltage is positive.

Crépieux, Adeline

2013-04-01

19

Hydraulic admittance of a partially saturated microfluidic slit  

NASA Astrophysics Data System (ADS)

Hydraulic admittance measurements have previously been performed on simple capillary systems as well as complex porous media such as gas diffusion layers. However, the theory for hydraulic admittance has yet to be developed for noncylindrical geometries in 2D channel studies. Here, hydraulic admittance theory is developed for a slit and experimentally measured for several hydraulic lengths (or partial saturation levels). Finite element modeling was included to address entrance effects associated with the sample. Both the theory and finite element modeling predicted higher hydraulic admittance magnitudes than measured, but the modeling predicted the resonance peak position better than the theory. The weak agreements to both the theory and modeling were mainly attributed to the slit approximation for the sample and additional interfacial curvature. Nonetheless, the resonance peaks were found to shift toward lower frequencies and decrease in magnitude with increasing hydraulic length for the theory, finite element modeling, and measurements.

Cheung, Perry; Schwartz, Daniel T.

2013-08-01

20

Structures that contribute to middle-ear admittance in chinchilla  

Microsoft Academic Search

We describe measurements of middle-ear input admittance in chinchillas (Chinchilla lanigera) before and after various manipulations that define the contributions of different middle-ear components to function. The\\u000a chinchilla’s middle-ear air spaces have a large effect on the low-frequency compliance of the middle ear, and removing the\\u000a influences of these spaces reveals a highly admittant tympanic membrane and ossicular chain. Measurements

John J. Rosowski; Michael E. Ravicz; Jocelyn E. Songer

2006-01-01

21

Molecular Characterization of Spontaneous Mesenchymal Stem Cell Transformation  

Microsoft Academic Search

Background. We previously reported the in vitro spontaneous transformation of human mesenchymal stem cells (MSC) generating a population with tumorigenic potential, that we termed transformed mesenchymal cells (TMC). Methodology\\/Principal Findings. Here we have characterized the molecular changes associated with TMC generation. Using microarrays techniques we identified a set of altered pathways and a greater number of downregulated than upregulated genes

Daniel Rubio; Silvia Garcia; Maria F. Paz; Teresa De la Cueva; Luis A. Lopez-Fernandez; Alison C. Lloyd; Javier Garcia-Castro; Antonio Bernad

2008-01-01

22

Validation of the computation of rocket nozzle admittances with linearized euler equations  

NASA Astrophysics Data System (ADS)

High pressure fluctuations coupled with unsteady heat release can affect a rocket engine seriously. Especially when the oscillations match eigenmodes such as T1, T1L1 and T2, T2L1, the acoustic pressure amplitude can reach a critical level. This paper deals with the investigation of the nozzle admittance, which is an important value to characterize the influence of the nozzle on the pressure inside the combustion chamber. Two different nozzle geometries are investigated experimentally at high frequencies. A method to decouple the acoustic modes is presented. The results are compared against an existing theory and simulated data.

Kathan, R.; Morgenweck, D.; Kaess, R.; Sattelmayer, T.

2013-03-01

23

Enforcing passivity for admittance matrices approximated by rational functions  

Microsoft Academic Search

A linear power system component can be included in a transient simulation as a terminal equivalent by approximating its admittance matrix Y by rational functions in the frequency domain. Physical behavior of the resulting model entails that it should absorb active power for any set of applied voltages, at any frequency. This requires the real part of Y to be

Bjørn Gustavsen; Adam Semlyen

2001-01-01

24

Infrastructure in the Electric Sense: Admittance Data from Shark Hydrogels  

Microsoft Academic Search

Elasmobranchs (sharks, skates, and rays) possess an electrosensory system with an infrastructure of canals connecting the electrosensors to the environment. The electrosensors and canals are filled with a uniform hydrogel, but the gel's function has not yet been determined. We present electrical admittance spectra collected from the hydrogel from 0.05 Hz to 100 kHz, covering the effective range of the

BRANDON R. BROWN; MARY E. HUGHES; CLEMENTINA RUSSO

2004-01-01

25

High Frequency Input Admittance of Continuum Regime Langmuir Probe  

NASA Astrophysics Data System (ADS)

Measurement of probe complex input impedance, or admittance, has been suggested as a way to increase the amount of information obtained from Langmuir probes [1]. In this poster, a spherical probe immersed in a weakly ionized homogeneous plasma is considered in the regime in which the probe radius is small compard with the Debye length. When the magnitude of the probe potential exceeds the plasma temperature in volts, the low frequency AC input admittance of the negatively biaed probe is given by the ion conductivity times 4? times the probe radius plus the admittance associated with the probe vacuum capacitance. The real part of the input admittance falls rapidly when the drive frequency exceeds the reciprocal of the time it takes ions to diffuse a distance on the order of the probe radius. An analytic solution to this problem found by applying the method of matched asymptotic expansions to the describing differential equation is given. Probe circuit models and boundary conditions are reviewed.[4pt] [1] D.N. Walker, R.F. Fernsler, D.D. Blackwell, and W.E. Amatucci, Phys. Plasmas 15, 123506 (2008).

Rappaport, H. L.

2010-11-01

26

Admittance Computations from Lunar Gravity and Topography Data  

Microsoft Academic Search

The admittance transfer function, calculated from the gravity and topography data in the spectral domain, can be used to compute the elastic thickness of a terrestrial planet, the effective thickness of the part of the lithosphere that can support elastic stresses over long time scales. This has been applied extensively in recent years to Venus and Mars due to new

S. Asmar; G. Schubert

2002-01-01

27

Infrastructure in the electric sense: admittance data from shark hydrogels  

Microsoft Academic Search

Elasmobranchs (sharks, skates, and rays) possess an electrosensory system with an infrastructure of canals connecting the electrosensors to the environment. The electrosensors and canals are filled with a uniform hydrogel, but the gel’s function has not yet been determined. We present electrical admittance spectra collected from the hydrogel from 0.05 to 100 kHz, covering the effective range of the electrosensors. We

Brandon R. Brown; Mary E. Hughes; Clementina Russo

2005-01-01

28

Characterizing seismic time series using the discrete wavelet transform  

SciTech Connect

The discrete wavelet transform (DWT) has potential as a tool for supplying discriminatory attributes with which to characterize or cluster groups of seismic traces in reservoir studies. The wavelet transform has the great advantage over the Fourier transform in being able to better localize changes. The multiscale nature and structure of the DWT leads to a method of display which highlights this and allows comparison of changes in the transform with changing data. Many different sorts of wavelet exist and it is found that the quality of reconstruction of a seismic trace wavelet exist and it is found that the quality of reconstruction of a seismic trace segment, using some of the coefficients, is dependent on the choice of wavelet, which leads us to consider choosing a wavelet under a best reconstruction criterion. Location shifts, time zero uncertainties, are also shown to affect the transform, as do truncations, resampling, etc. Using real data, examples of utilizing the DWT coefficients as attributes for whole trace segments or fractional trace segments are given. Provided the DWT is applied consistently, for example with a fixed wavelet, and non-truncated data, the transform produces useful results. Care must be exercised if it is applied to data of different lengths. However, as the algorithm is refined and improved in the future, the DWT should prove increasingly useful.

Grubb, H.J.; Walden, A.T. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Mathematics

1997-03-01

29

TRANSFORMER  

DOEpatents

Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

Baker, W.R.

1959-08-25

30

Cloning, expression, and characterization of chicken transforming growth factor ?4  

Microsoft Academic Search

Transforming growth factor ?4 (TGF-?4) is unique to avian species, though its roles in vivo have not yet been well established. In this paper we describe the expression and partial characterization of recombinant chicken TGF-?4. By using a GC-rich PCR system in a modified 5?RACE methodology we generated the 5?-end of cDNA sequence encoding the TGF-?4 precursor, which was in-frame

Hongjie Pan; Jaroslava Halper

2003-01-01

31

Admittance survey of type 1 coronae on Venus  

NASA Astrophysics Data System (ADS)

In this study, we analyze Magellan gravity and topography data for Type 1 coronae on Venus to estimate crustal thickness (Zc), elastic thickness (Te), and apparent depth of compensation (ZL). We examine the free-air admittance for all 103 Type 1 coronae (defined as having greater than 50% complete fracture annuli) that are resolved in the gravity data. A spatio-spectral method is used to calculate a localized admittance signature of each corona from a global admittance map. This method extracts spectral information from a region in space whose area is varied as a function of degree to make it large enough to yield robust results at every individual wavelength. Elastic flexure models with either bottom- or top-loading compensation are used to fit the data. The estimated lithospheric flexural parameters span the range obtained for other topographic features on Venus, suggesting that the lithosphere on which coronae form is variable. We find no significant difference in lithospheric properties between Type 1 and 2 coronae. Fifty-four percent of all coronae are consistent with local isostasy, which may indicate that they are no longer active. Very few coronae with dome or plateau morphologies have a bottom-loading signature or the small Te and large ZL expected if a mantle plume were present. Approximately 71% have ZL estimates less than 70 km, indicating that compensation probably occurs within the crustal layer. We find no systematic relationship between Te or Zc and corona diameter, as would be expected for the spreading-drop model of formation.

Hoogenboom, Trudi; Smrekar, Suzanne E.; Anderson, F. Scott; Houseman, Greg

2004-03-01

32

PEDOT:PSS polymeric conducting anode for admittance spectroscopy  

Microsoft Academic Search

The carrier mobilities of two hole transporting organic materials were evaluated by admittance spectroscopy (AS). The materials were 4,4?,4?-tris{N,-(3-methylphenyl)-N-phenylamino}triphenylamine (m-MTDATA) and N,N?-diphenyl-N,N?-bis(1,1?-biphenyl)-4,4?-diamine (NPB). They were sandwiched in a configuration of anode\\/organic material\\/cathode. The anode was either indium-tin-oxide (ITO) or poly(3,4-ethylenedioxythiophene) doped with polystrenesulphonic acid (PEDOT:PSS). It is shown that PEDOT:PSS can, respectively, form Ohmic and quasi-Ohmic contact with m-MTDATA and

S. W. Tsang; S. C. Tse; K. L. Tong; S. K. So

2006-01-01

33

Method for measuring transformation energy and quantitative characterization of transformation-induced plasticity  

Microsoft Academic Search

A method for measuring transformation energy (E\\u000a pt) of strain-induced martensite (SIM) and quantitative characterization of transformation-induced plasticity is developed using\\u000a characteristics of the tensile curve of three metastable austenitic stainless steels, 10Cr18.5Ni8.5Mnl.9Si0.9, 19Cr17.5Ni7.4Mn2.3Si1.0,\\u000a and 10Cr16.2Ni11.8Mn1.2Si0.7. The results show that the E\\u000a pt of tested materials at ?196 C is 11.3, 14.7, and 20.1106 J\\/m3, respectively; E\\u000a pt remains constant

W. F. Zhang; Y. M. Chen; J. H. Zhu

2002-01-01

34

Quality control of dairy products using single frequency admittance measurements  

NASA Astrophysics Data System (ADS)

A reusable device for the detection of adulteration in dairy products such as milk and cream has been developed. The ac electrical admittance spectra of different samples have been studied using both uncoated and alkyl mercaptan-coated gold electrodes. Uncoated gold electrodes exhibited a polarization at around 250 Hz for full fat milk, while mercaptan-coated gold electrodes showed a similar effect at around 2 kHz. The characteristics at 100 kHz and 8 °C for all skimmed milk samples revealed a linear decrease in conductance with increasing water content over the entire range of water concentration. In contrast, the conductance of full fat milk, single and double cream, showed a linear decrease only at added water concentration higher than 6%. At lower concentrations, these dairy products exhibited anomalous conductivity maxima.

Mabrook, M. F.; Darbyshire, A. M.; Petty, M. C.

2006-02-01

35

Frequency-dependent admittance of a three-probe mesoscopic conductor  

NASA Astrophysics Data System (ADS)

By considering of two factors, the hopping of electrons between different channels in the scattering on the interfaces of different regions the contact effect, we investigate in a self-consistent manner the frequency-dependent admittance of a three-probe mesoscopic conductor connected with wide reservoirs. Results indicate that the frequency-dependent admittance shows two different responses to an external ac voltage, namely, inductive-like and capacitive-like, which depend on the sign of the matrix elements of the admittance. Importantly, the contact effect can cause a significant difference in the frequency-dependent electrons transport properties, especially in high-frequency cases.

Chuen, J.; Tian, Ying

2013-03-01

36

Fault detection system including a capacitor for generating a pulse and a processor for determining admittance versus frequency of a reflected pulse  

US Patent & Trademark Office Database

A system comprising a portable apparatus and employing a method of admittance versus frequency analysis to detect the existence of a fault in a de-energized electrical line regardless of whether the line contains branches. The portable apparatus comprises a capacitor unit detachably connected to a de-energized line, ground or a neutral conductor, a switch unit detachably connected to a de-energized line, the de-energized line being tested, and an insulated cable connecting the capacitor unit to the switch unit. The switch unit comprises a discharge switch that can be activated by pulling on the hot line tool. The capacitor unit comprises a capacitor which is discharged into the electrical line via the insulated cable and the switch unit when the discharge switch is activated to create a pulse. The capacitor unit comprises circuitry for generating voltage and current samples of pulse response signals and a microprocessor for determining the admittance of the electrical line using Fast Fourier transforms of the current and voltage samples. The admittance of the line is compared with stored data relating to lines having different load impedances and having faults located at various distances from the capacitor unit and detectable at various frequencies to determine the existence of a fault.

Rhein; David Adelbert (Columbia, MO); Beard; Lloyd Ronald (Centralia, MO); Roberts; Gerald Bernard (Paris, MO); Herrick; Thomas Jude (Rolla, MO)

1997-07-22

37

48 CFR 3022.101-70 - Admittance of union representatives to DHS installations.  

Code of Federal Regulations, 2011 CFR

...HSAR) SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Basic Labor Policies 3022.101-70 Admittance...representatives to Transportation Security Administration or United States Secret Service installations and work sites is not...

2011-10-01

38

48 CFR 3022.101-70 - Admittance of union representatives to DHS installations.  

Code of Federal Regulations, 2012 CFR

...HSAR) SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Basic Labor Policies 3022.101-70 Admittance...representatives to Transportation Security Administration or United States Secret Service installations and work sites is not...

2012-10-01

39

Direct identification of flutter derivatives and aerodynamic admittances of bridge decks  

Microsoft Academic Search

Flutter derivatives and aerodynamic admittances provide basis of predicting the critical wind speed in flutter and buffeting analysis of long-span cable-supported bridges. In this paper, one popular stochastic system identification technique, covariance-driven stochastic subspace identification (SSI in short), is first presented for estimation of the flutter derivatives and aerodynamic admittances of bridge decks from their random responses in turbulent flow.

Ming Gu; Xian-Rong Qin

2004-01-01

40

Small signal admittance spectroscopy applied for extraction of charge carrier mobility in thin organic layers  

NASA Astrophysics Data System (ADS)

The work presents new way of extraction of charge carrier mobility from small signal spectra of admittance. It can be a useful method for thin organic layers in a sandwich arrangement. It is better than the version of small signal admittance currently applied for getting charge carrier mobility, since the final result is not charged with uncertainty of geometric capacitance and the upper limit of measurable charge carrier mobility is higher.

Jarosz, G.; Signerski, R.

2011-12-01

41

Characterization of a transformed rat retinal ganglion cell line  

Microsoft Academic Search

The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the ?2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells.

R. R. Krishnamoorthy; P. Agarwal; G. Prasanna; K. Vopat; W. Lambert; H. J. Sheedlo; I.-H. Pang; D. Shade; R. J. Wordinger; T. Yorio; A. F Clark; N. Agarwal

2001-01-01

42

Surface plasmon resonance based sensing of different chemical and biological samples using admittance loci method  

NASA Astrophysics Data System (ADS)

The admittance loci method plays an important role in the design of multilayer thin film structures. In this paper, admittance loci method has been explored theoretically for sensing of various chemical and biological samples based on surface plasmon resonance (SPR) phenomenon. A dielectric multilayer structure consisting of a Boro silicate glass (BSG) substrate, calcium fluoride (CaF2) and zirconium dioxide (ZrO2) along with different dielectric layers has been investigated. Moreover, admittance loci as well as SPR curves of metal-dielectric multilayer structure consisting of the BSG substrate, gold metal film and various dielectric samples has been simulated in MATLAB environment. To validate the proposed simulation results, calibration curves have also been provided.

Brahmachari, Kaushik; Ghosh, Sharmila; Ray, Mina

2013-06-01

43

Gravity/topography admittance inversion on Venus using niching genetic algorithms  

NASA Astrophysics Data System (ADS)

We used niching genetic algorithms (NGAs) to invert localized Venus gravity/topography admittance over lowland regions Atalanta and Lavinia Planitiae, as well as volcanic rise Atla Regio for comparison. Assuming both top (topography) and bottom (mantle density anomalies) loads, we calculated theoretical admittance using thin elastic shell models. We inverted admittance for crustal thickness, elastic lithosphere thickness, mantle density anomaly thickness, and ratio (pz) of mantle density anomaly to topographic load. NGA inversion provides an efficient means of finding globally optimal and sub-optimal solutions. Error analyses of all three regions show that pz is a robust estimate; there is significant trade-off between elastic lithosphere and mantle anomaly thicknesses, while crustal thickness is ill-constrained. Optimal models suggest that mantle density anomalies are ~+1 to 2% underlying lowland regions and ~-3 to -4% underlying Atla Regio.

Lawrence, Kristin P.; Phillips, Roger J.

2003-10-01

44

Transformations  

NSDL National Science Digital Library

In this webquest, fourth grade students will be learning how to transform geometric shapes. They will also learn to define transformation, translation, and reflection. Introduction You are going to become math detectives. You will try and solve what a transformation is and how you use it. When you are finished you will be able to perform many different transformations. You will be able to identify many different geometric ...

Foust, Mrs.

2005-10-31

45

In-situ characterization of transformation plasticity during an isothermal austenite-to-bainite phase transformation  

SciTech Connect

This paper elucidates the stress-induced variant selection process during the isothermal austenite-to-bainite phase transformation in a tool steel. Specifically, a thorough set of experiments combining electron backscatter diffraction and in-situ digital image correlation (DIC) was carried out to establish the role of superimposed stress level on the evolution of transformation plasticity (TP) strains. The important finding is that TP increases concomitant with the superimposed stress level, and strain localization accompanies phase transformation at all stress levels considered. Furthermore, TP strain distribution within the whole material becomes more homogeneous with increasing stress, such that fewer bainitic variants are selected to grow under higher stresses, yielding a more homogeneous strain distribution. In particular, the bainitic variants oriented along [101] and [201] directions are favored to grow parallel to the loading axis and are associated with large TP strains. Overall, this very first in-situ DIC investigation of the austenite-to-bainite phase transformation in steels evidences the clear relationship between the superimposed stress level, variant selection, and evolution of TP strains. - Highlights: Black-Right-Pointing-Pointer Local variations of strain were observed by DIC throughout the phase transformation. Black-Right-Pointing-Pointer The study clearly established the role of the stress-induced variant selection. Black-Right-Pointing-Pointer Variant selection is a key parameter that governs distortion.

Holzweissig, M.J., E-mail: martinh@mail.upb.de [University of Paderborn, Lehrstuhl fuer Werkstoffkunde (Materials Science), 33095 Paderborn (Germany); Canadinc, D., E-mail: dcanadinc@ku.edu.tr [Koc University, Advanced Materials Group, Department of Mechanical Engineering, 34450 Istanbul (Turkey); Maier, H.J., E-mail: hmaier@mail.upb.de [University of Paderborn, Lehrstuhl fuer Werkstoffkunde (Materials Science), 33095 Paderborn (Germany)

2012-03-15

46

A high frequency transformer model for the EMTP  

SciTech Connect

A model to simulate the high frequency behavior of a power transformer is presented. This model is based on the frequency characteristics of the transformer admittance matrix between its terminals over a given range of frequencies. The transformer admittance characteristics can be obtained from measurements or from detailed internal models based on the physical layout of the transformer. The elements of the nodal admittance matrix are approximated with rational functions consisting of real as well as complex conjugate poles and zeros. These approximations are realized in the form of an RLC network in a format suitable for direct use with EMTP. The high frequency transformer model can be used as a stand-alone linear model or as an add-on module of a more comprehensive model where iron core nonlinearities are represented in detail.

Morched, A.; Marti, L.; Ottevangers, J. (Ontario Hydro, Toronto (Canada))

1993-07-01

47

The effect of otitis media in childhood on the development of middle ear admittance on reaching adulthood  

Microsoft Academic Search

OBJECTIVES: To determine the long-term change in static admittance values of subjects with a positive or negative history of otitis media (OM) and ventilation tube (VT) insertion; and to investigate the association between static admittance values and tympanic membrane abnormalities. DESIGN: Prospective follow-up study. SUBJECTS: A total of 358 subjects with or without a history of OM (OM+ or OM-)

Brechtje de Beer; A. F. M. Snik; Anne G. M. Schilder; Kees Graamans; Gerhard A. Zielhuis

2005-01-01

48

Molecular characterization of bacteria isolated from waste electrical transformer oil  

Microsoft Academic Search

Electrical transformer oil (ETO) includes as dielectric fluids hazardous compounds such as PAHs and sometimes PCBs, which\\u000a are highly toxic and resistant to degradation. Three species of bacteria, belonging to Acinetobacter lwoffii, Bacillus amyloliquefaciens, and Bacillus pumilus, were isolated from waste ETO. Phenotypic and molecular assays revealed a high potential of A. lwoffii for catabolism of phenanthrene and ETO as

A. de Sisto; E. Fusella; H. Urbina; V. Leyn; L. Naranjo

2008-01-01

49

Isolation and Characterization of Reticuloendotheliosis Virus Transformed Bone Marrow Cells  

Microsoft Academic Search

Summary Transformed cells have been isolated from the bone marrow of reticuloendotheliosis virus (REV)-infected, moribund chicks. These cells have been maintained in vitro through more than 30 serial passages. The cells induce solid tumors when inoculated into the wing web of day-old chickens, and cell-free filtrates induce reticuloendotheliosis. Virus particles recovered after cocultivation of bone marrow cells and chicken embryo

Ray B. Franklin; Reynaldo L. Maldonado; Henry R. Bose

1974-01-01

50

Identification of defect types in moderately Si-doped GaInNAsSb layer in p-GaAs/n- GaInNAsSb/n-GaAs solar cell structure using admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Bias dependence of the admittance spectroscopy of GaInNAsSb based solar cell structure has been performed to identify and characterize the type of defects, for example interface and/or bulk type defects in a moderately Si doped GaInNAsSb (n-GaInNAsSb) layer in the structure. From the zero bias admittance spectrum, three peaks namely E1, E2, and E3 corresponding to the localized level at 0.03 eV, 0.07 eV, and 0.16 eV below the conduction band edge (EC) of n-GaInNAsSb material, respectively, were found. Constant position of E2 and E3 peak in the admittance spectra in response to the various applied DC reverse bias suggests that E2 and E3 are related to the bulk type defects being spatially homogeneous throughout the bulk of the n- GaInNAsSb film. However, bias dependence admittance of the E1 peak along with the capacitance - voltage (C-V) measurement as well as characteristic feature in the temperature dependent junction capacitance value strongly suggests that E1 peak might be originated due to the free carrier relaxation in the n- GaInNAsSb layer in lower temperature. Conduction mechanism in the freeze-out regime has been discussed. Analysis of the admittance peak, E1 together with the characteristic features in the frequency dependence of the conduction in freeze out regime suggest that conduction properties of the n-GaInNAsSb material in the freeze-out condition is governed by Mott's variable range hopping mechanism.

Monirul Islam, Muhammad; Miyashita, Naoya; Ahsan, Nazmul; Sakurai, Takeaki; Akimoto, Katsuhiro; Okada, Yoshitaka

2012-12-01

51

Calculation of Characteristic Admittances and Coupling Coefficients for Strip Transmission Lines  

Microsoft Academic Search

An integral equation technique is presented which may be used to efficiently compute the Maxwellian capacitance matrix, i.e., the coefficients of capacitance and inductance, for any system of zero-thickness strip conductors located parallel to and between two ground planes, The TEM characteristic admittances for various operating modes and the coupling coefficients can then be obtained from the elements of this

D. W. Kammler

1968-01-01

52

Sensitivity-enhanced admittance-based structure health monitoring using a higher-order resonant circuit  

NASA Astrophysics Data System (ADS)

An admittance-based structure health monitoring method with a higher-order resonant circuit is proposed and investigated in this paper, with the advantage of increased damage detection sensitivity. The change of the stiffness or mass in the structure due to damage can be detected by measuring the admittance from the piezoelectric transducer adhered to the host structure. It is known that designing an inductive circuitry, together with the piezoelectric capacitance, can introduce an additional resonance and yield enhanced sensitivity. In this paper, based on the electrical-mechanical analogy, a novel higher-order resonant circuit is designed and optimized to significantly improve the damage detection capability, i.e. increasing the admittance magnitude and its sensitivity to damage. Theoretical analyses and simulations are carried out. The results show that the peak admittance magnitude is increased by 74 dB for the higher-order circuit without electrical damping and 46 dB with electrical damping, when comparing with the second-order circuit system. The damage detection sensitivity is increased by 33 dB and 36 dB for a stiffness change of 0.5% and 1%, respectively, by using the proposed higher-order circuit, when comparing with the second-order circuit system, and even more when comparing with the traditional method with only a resistor.

Zhou, Wanlu; Zuo, Lei

2012-10-01

53

The effect of an offset impedance sheet on the admittance of a slot antenna  

Microsoft Academic Search

The effect of offsetting a plasma (or dielectric) from an infinite slot antenna excited with a TEM mode in a conducting plane is considered, using an impedance sheet as a model for the plasma. Results are obtained for the change in antenna admittance as a function of offset distance for several different values of plasma (dielectric) surface impedance and characteristic

R. Fante

1967-01-01

54

Voltage dependence of Na channel blockage by amiloride: Relaxation effects in admittance spectra  

Microsoft Academic Search

Summary Amiloride, present in the mucosal solution, causes the appearance of a distinct additional dispersion in the admittance spectrum of the apical membrane of toad urinary bladder. The parameters of this dispersion (characteristic frequency. amplitude) change with amiloride concentration and with membrane voltage. They allow the calculation of the overall rate constants for Na channel blockage by the positively charged

Jens Warncke; Bernd Lindemann

1985-01-01

55

Localized Gravity\\/Topography Correlation and Admittance Spectra one the Moon  

Microsoft Academic Search

Lunar surface and structure can be separate into two parts. The lunar near side crust and far side crust differ remarkably in thickness. This difference probably caused by difference of thermal evolution and state (elastic thickness) and catering history on both side. The correlations and admittance between the topography and gravity anomalies provide important information on the level of isostatic

Y. Ishihara; N. Namiki; S. Sugita; K. Matsumoto; S. Goossens; H. Araki; H. Noda; S. Sasaki; T. Iwata; H. Hanada

2009-01-01

56

A General Formulation for Admittance of an Open-Ended Rectangular Waveguide Radiating into Stratified Dielectrics  

Microsoft Academic Search

A general approach is presented for calculating the aperture admittance of a rectangular waveguide radiating into layered dielectric media. The two specific geometries of stratified, lossy dielectric media that are addressed terminate into either an infinite half-space or a perfectly conducting surface. The geometries describe two prevalent categories of layered dielectric composites and coatings that often are encountered in practical

S. Bakhtiari; S. Ganchev; R. Zoughi

1995-01-01

57

Admittance measurements to assess the total solids and fat contents in liquid whole egg products  

Microsoft Academic Search

In the present research, a method based on admittance measurements able to assess total solids and fat contents (%) in nine different liquid whole egg products was set up. By means of a tetrapolar platinum cell connected to a signal conditioning circuit, an alternating current generator and a data acquisition system, the effect of 15 different combinations of frequencies of

Luigi Ragni; Annachiara Berardinelli; Chiara Cevoli; Federico Sirri

2011-01-01

58

Measurement of the acoustic admittance of the burning surface of gunpowder  

Microsoft Academic Search

The acoustic admittance of a burning surface is a fundamental physical property which defines the tendency of gunpowder to acoustic instability of combustion. Under conditions of acoustic instability of combustion of condensed systems, pressure waves are usually intensified at the burning surface of gunpowder in the narrow zone of intense chemical reactions. The characteristic dimensions of this zone are small

A. D. Margolin; I. B. Svetlichnyi; P. F. Pokhil; A. S. Tsirul'nikov

1970-01-01

59

Effect of Nonzero Surface Admittance on Receptivity and Stability of Compressible Boundary Layer.  

National Technical Information Service (NTIS)

The effect of small-amplitude short-scale variations in surface admittance on the acoustic receptivity and stability of two-dimensional compressible boundary layers is examined. In the linearized limit, the two problems are shown to be related both physic...

M. Choudhari

1994-01-01

60

Admittance and radiation efficiency of the human body in the resonance region  

Microsoft Academic Search

By using the body as a monopole antenna the admittance and radiation efficiency have been measured in the frequency range 30-70 MHz. It is concluded that there are no resonance effects. The efficiency is about -2 dB at the higher frequencies.

J. B. Andersen; P. Balling

1972-01-01

61

TRANSFORMATION  

SciTech Connect

Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

LACKS,S.A.

2003-10-09

62

Isolation and characterization of an anaerobic chlorophenol-transforming bacterium.  

PubMed Central

An obligately anaerobic bacterium which transforms several chlorinated phenols was isolated. Dechlorination of the substituents ortho to the phenolic OH group was preferred, while removal of a meta-substituted chlorine was observed only with 3,5-dichlorophenol. The bacterium was a gram-positive, endospore-forming, motile, slightly curved rod. Sulfate was not reduced. Nitrate was reduced via nitrite to ammonium. The bacterium is related to the genus Clostridium. The highest growth rate was obtained in a medium containing pyruvate and yeast extract. Pyruvate supported growth as the sole source of carbon, and the fermentation of pyruvate produced almost equimolar amounts of acetate. Images

Madsen, T; Licht, D

1992-01-01

63

A Method to Measure the Relationship Between Biodynamic Feedthrough and Neuromuscular Admittance.  

PubMed

Biodynamic feedthrough (BDFT) refers to a phenomenon where accelerations cause involuntary limb motions, which can result in unintentional control inputs that can substantially degrade manual control. It is known that humans can adapt the dynamics of their limbs by adjusting their neuromuscular settings, and it is likely that these adaptations have a large influence on BDFT. The goal of this paper is to present a method that can provide evidence for this hypothesis. Limb dynamics can be described by admittance, which is the causal dynamic relation between a force input and a position output. This paper presents a method to simultaneously measure BDFT and admittance in a motion-based simulator. The method was validated in an experiment. Admittance was measured by applying a force disturbance signal to the control device; BDFT was measured by applying a motion disturbance signal to the motion simulator. To allow distinguishing between the operator's responses to each disturbance signal, the perturbation signals were separated in the frequency domain. To show the impact of neuromuscular adaptation, subjects were asked to perform three different control tasks, each requiring a different setting of the neuromuscular system (NMS). Results show a dependence of BDFT on neuromuscular admittance: A change in neuromuscular admittance results in a change in BDFT dynamics. This dependence is highly relevant when studying BDFT. The data obtained with the proposed measuring method provide insight in how exactly the settings of the NMS influence the level of BDFT. This information can be used to gain fundamental knowledge on BDFT and also, for example, in the development of a canceling controller. PMID:21349792

Venrooij, Joost; Abbink, David A; Mulder, Mark; van Paassen, Marinus M; Mulder, Max

2011-02-24

64

CHARACTERIZATION OF LYMPHOCYTE TRANSFORMATION INDUCED BY ZINC IONS  

PubMed Central

Lymphocyte cultures from all normal human adults are stimulated by zinc ions to increase DNA and RNA synthesis and undergo blast transformation. Optimal stimulation occurs at 0.1 mM Zn++. Examination of the effects of other divalent cations reveals that 0.01 mM Hg++ also stimulates lymphocyte DNA synthesis. Ca++ and Mg++ do not affect DNA synthesis in this culture system, while Mn++, Co++, Cd++, Cu++, and Ni++ at concentrations of 10-7–10-3 M are inhibitory. DNA and RNA synthesis and blast transformation begin to increase after cultures are incubated for 2–3 days with Zn++ and these processes reach a maximum rate after 6 days. The increase in Zn++-stimulated lymphocyte DNA synthesis is prevented by rendering cells incapable of DNA-dependent RNA synthesis with actinomycin D or by blocking protein synthesis with cycloheximide or puromycin. Zn++-stimulated DNA synthesis is also partially inhibited by 5'-AMP and chloramphenicol. Zn++ must be present for the entire 6-day culture period to produce maximum stimulation of DNA synthesis. In contrast to its ability to independently stimulate DNA synthesis, 0.1 mM Zn++ inhibits DNA synthesis in phytohemagglutinin-stimulated lymphocytes and L1210 lymphoblasts.

Berger, Nathan A.; Skinner, Sister Ann Marie

1974-01-01

65

A unified three-phase transformer model for distribution load flow calculations  

Microsoft Academic Search

This paper provides a unified method to model three-phase transformers for distribution system load flow calculations, especially when the matrix singularity caused by the transformer configuration arises. This paper shows that the singularity appears only in certain transformer admittance submatrices and only in certain transformer configurations. The unified method presented in this paper can solve the voltage\\/current equations in the

Peng Xiao; David C. Yu; Wei Yan

2006-01-01

66

Transformation  

NSDL National Science Digital Library

This video clip demonstrates the process of transformation. When a bacterial cell dies, the DNA in the cell breaks into fragments. This free DNA can be taken up by certain bacteria and integrated into their DNA.

American Society For Microbiology;

2002-01-01

67

A Characterization of Attributed Tree Transformations by a Subclass of Macro Tree Transducers  

Microsoft Academic Search

.    We present a characterization of the class of tree transformations computed by (noncircular) attributed tree transducers,\\u000a in terms of a subclass of macro tree transducers, called attributed-like macro tree transducers. In fact, we prove formally\\u000a that attributed tree transducers and attributed-like macro tree transducers generate the same class of tree transformations.\\u000a Moreover, we prove that it is decidable

Zoltán Fülöp; Heiko Vogler

1999-01-01

68

Validation of admittance computed left ventricular volumes against real-time three-dimensional echocardiography in the porcine heart.  

PubMed

The admittance and Wei's equation is a new technique for ventricular volumetry to determine pressure-volume relations that addresses traditional conductance-related issues of parallel conductance and field correction factor. These issues with conductance have prevented researchers from obtaining real-time absolute ventricular volumes. Moreover, the time-consuming steps involved in processing conductance catheter data warrant the need for a better catheter-based technique for ventricular volumetry. We aimed to compare the accuracy of left ventricular (LV) volumetry between the new admittance catheterization technique and transoesophageal real-time three-dimensional echocardiography (RT3DE) in a large-animal model. Eight anaesthetized pigs were used. A 7 French admittance catheter was positioned in the LV via the right carotid artery. The catheter was connected to an admittance control unit (ADVantage; Transonic Scisense Inc.), and data were recorded on a four-channel acquisition system (FA404; iWorx Systems). Admittance catheterization data and transoesophageal RT3DE (X7-2; Philips) data were simultaneously obtained with the animal ventilated, under neuromuscular blockade and monitored in baseline conditions and during dobutamine infusion. Left ventricular volumes measured from admittance catheterization (Labscribe; iWorx Systems) and RT3DE (Qlab; Philips) were compared. In a subset of four animals, admittance volumes were compared with those obtained from traditional conductance catheterization (MPVS Ultra; Millar Instruments). Of 37 sets of measurements compared, admittance- and RT3DE-derived LV volumes and ejection fractions at baseline and in the presence of dobutamine exhibited general agreement, with mean percentage intermethod differences of 10% for end-diastolic volumes, 14% for end-systolic volumes and 9% for ejection fraction; the respective intermethod differences between admittance and conductance in eight data sets compared were 11, 11 and 12%. Admittance volumes were generally higher than those obtained by RT3DE, especially among the larger ventricles. It is concluded that it is feasible to derive pressure-volume relations using admittance catheterization in large animals. This study demonstrated agreements between admittance and RT3DE to within 10-14% mean intermethod difference in the estimation of LV volumes. Further investigation will be required to examine the accuracy of volumes in largest ventricles, where intermethod divergence is greatest. PMID:23435903

Kutty, Shelby; Kottam, Anil T; Padiyath, Asif; Bidasee, Keshore R; Li, Ling; Gao, Shunji; Wu, Juefei; Lof, John; Danford, David A; Kuehne, Titus

2013-02-22

69

Fourier-transform Raman characterization of brazilwood trees and substitutes.  

PubMed

In this work we have applied Fourier-transform Raman spectroscopy to the analysis of several archival samples of brazilwoods from different geographical origins and of different ages. Samples of Caesalpinia echinata Lam. (from Brazil, South America), Caesalpinia sappan L. (East Indies, Asia), Haematoxylum brasiletto Karsten (Central America) and Haematoxylum campechianum L. (North America) were analysed in order to isolate key Raman biomarker bands which could provide the basis for an identification protocol. Previously recorded Raman spectra of brazilin and brazilein pigments extracted from genuine brazilwood of Brazilian origin provided a foundation for the nondestructive spectral discrimination between a sample of false 'brazilwood', which consisted of an inferior wood substratum stained with genuine pigment, and the true specimens. The provision of well-documented specimens of determinable age from the archival collection facilitated the evaluation of the effects of temporal degradation on the observed spectra, which could be used to further test the experimental protocols for nondestructive verification of samples in the archive with questionable assignment or provenance. PMID:12572809

Edwards, Howell G M; de Oliveira, Luiz F C; Nesbitt, Mark

2003-01-01

70

Transformers  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Transformers, is the ninth chapter in Volume II âÂÂAlternating Current (AC). A few of the topics covered in this chapter include: Mutual inductance and basic operation; Step-up and Step-down transformers; Electrical isolation; Phasing; Winding configurations; Voltage Regulation; and finally, Special transformers and applications.. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-03

71

Synthesis, characterization and structural transformation of a discrete tetragonal metalloprism.  

PubMed

A novel M(2)L(4) tetragonal metalloprism, [(NO(3)(-))?{Cu(2)(?-Hdpma)(4)}(NO(3))(2)](NO(3))(5) (1), was prepared from the self-assembly reaction of Cu(NO(3))(2)·3H(2)O and flexible clip-like organic ligand di(3-pyridylmethyl)amine (dpma) under acidic conditions. The cationic prismatic hollow structure of 1 hosts one nitrate anion via both metal-ligand dative bonds and electrostatic interactions. Metalloprism 1 can dissolve in water and its prismatic structure remains intact as supported by ESI-MS data. When metalloprism 1 was treated with sodium thiocyanate and sodium azide in aqueous solutions, two polymeric coordination architectures, [Cu(?-Hdpma)(2)(NCS)(2)](NO(3))(2) (2) and [Cu(?-dpma)(2)(?-1,1-N(3))(?-1,3-N(3))] (3), formed at room temperature, respectively. Polymer 2 has a two-dimensional sheet structure showing a simple rhombic 4(4)-sql topology in network connectivity, whereas polymer 3 gives a three-dimensional uninodal pcu net. The conformation of the flexible ditopic ligand is varied from a trans-trans-syn conformer in 1 to a trans-trans-anti conformer in 2 and to a trans-gauche-anti conformer in 3. The observations imply the occurrence of structural transformation from a discrete metalloprism into polymeric coordination architectures via a decoordination/rearrangement process. Magnetic studies of metalloprism 1 suggest that the two Cu(II) centers are weakly antiferromagnetically coupled. The spins communicate via the nitrate template while the Cu···O(nitrate) interactions are weak. For polymer 3, a ferromagnetically coupled system (J(2) = +17.6 cm(-1)) is operative between two Cu(II) centers bridged by end-on azidos and an antiferromagnetic coupling (J(1) = -7.7 cm(-1)) between two Cu(II) centers with end-to-end azidos. In contrast to relatively large coupling values of the reported examples, the weak ferromagnetic interaction results from insufficient spin delocalization between two Cu(II) centers. PMID:22094892

Wu, Jing-Yun; Zhong, Ming-Shiou; Chiang, Ming-Hsi; Tsai, Meng-Rong; Lai, Long-Li

2011-11-17

72

Transformer \\  

Microsoft Academic Search

Reduction of size and weight in electronic type transformers to keep pace with miniaturization in other phases of electronic component designing has led directly to higher temperature operation. Temperatures in the region of 185°C require inorganic materials throughout, including where used, the dielectric coolant. Design details and materials performance in \\

L. F. Kilham; R. R. Ursch

1956-01-01

73

Transformers  

Microsoft Academic Search

Purpose – The aim of this paper is to examine the current and future outlook of smartphones and how they will transform the loyalty marketing landscape. Design\\/methodology\\/approach – The approoach takes the form of tapping big-name companies, like Nielsen, Ogilvy and Wells Fargo, to provide insight into how marketers are looking to utilize smartphones and to predict where the future

Sharon M. Goldman

2010-01-01

74

76 FR 31306 - Admittance to Practice and Roster of Registered Patent Attorneys and Agents Admitted to Practice...  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF COMMERCE Patent and Trademark Office Admittance to Practice and Roster...Practice Before the United States Patent and Trademark Office (USPTO) (Proposed Addition...SUMMARY: The United States Patent and Trademark Office (USPTO), as part of its...

2011-05-31

75

Full wave coupled resonator filter optimization using a multi-port admittance-matrix  

Microsoft Academic Search

A filter optimization strategy based on full wave EM simulations is proposed. With the introduction of additional internal ports in the filter model, the multi-port admittance-matrix (Y-matrix) is obtained. The main advantage lies in the fact that the filter's basic parameters, as there are the resonant frequency of each resonator, the coupling coefficients and the external Qs are directly accessible

S. Otto; A. Lauer; J. Kassner; A. Rennings

2006-01-01

76

Development of a trans-admittance mammography (TAM) using 60×60 electrode array  

NASA Astrophysics Data System (ADS)

We have developed a trans-admittance mammography (TAM) system as a supplementary or alternative method of the X-ray mammography to diagnose the breast cancer. Mechanical structure of the system is similar to the X-ray mammography with the breast placed between two plates. The pair of plates is movable to accommodate breasts with different sizes and rotatable to provide multiple images with different projection angles. Without using ionizing radiation, it acquires a projection image of tissue admittivity values. One plate is a flat solid electrode where we apply a constant sinusoidal voltage with a variable frequency. The other is equipped with 60×60 array of current-sensing electrodes, of which potentials are kept at the signal reference level. The electrode array is connected to six switching modules and each module routes current signals from 600 electrodes to two ammeter modules. Each ammeter module includes six channels of ammeters and each one of them comprises an independent current-to-voltage converter, voltage amplifier, ADC and digital phase-sensitive demodulator. Each ammeter sequentially measures exit currents from 50 electrodes chosen by the corresponding switching module. An FPGA controls six ammeters to collect real- and imaginary-parts of trans-admittance data from 300 electrodes. A separate FPGA arbitrates data and command exchanges between a DSP-based main controller and ammeter modules. It also generates a sinusoidal voltage signal to be applied to the breast. All the 3600 complex current data from 12 ammeter modules are transferred to the main controller, which is interfaced to a PC through an isolated USB. The system is provided with a program to display real- and imaginary-parts of measured trans-admittance maps. The measured maps at multiple frequencies are incorporated into a frequency-difference anomaly detection algorithm. In this paper, we describe the design and construction of the system.

Zhao, Mingkang; Liu, Qin; In Oh, Tong; Woo, Eung Je; Seo, Jin Keun

2010-04-01

77

A general formulation for admittance of an open-ended rectangular waveguide radiating into stratified dielectrics  

Microsoft Academic Search

A general approach is presented for calculating the aperture admittance of a rectangular waveguide radiating into layered\\u000a dielectric media. The two specific geometries of stratified, lossy dielectric media that are addressed terminate into either\\u000a an infinite half-space or a perfectly conducting surface. The geometries describe two prevalent categories of layered dielectric\\u000a composites and coatings that often are encountered in practical

S. Bakhtiari; S. Ganchev; R. Zoughi

1995-01-01

78

A FORM OF AERODYNAMIC ADMITTANCE FOR USE IN BRIDGE AEROELASTIC ANALYSIS  

Microsoft Academic Search

This paper returns to, and addresses, the question of identifying the nature of aerodynamic admittance in relation to extended-span bridges in wind. Theoretical formulations for the sectional aerodynamic forces acting upon the deck girder of a long-span bridge have conventionally been composed of the sum of two kinds of terms: aeroelastic terms and buffeting terms. The former employ frequency-dependent coefficients

R. H. SCANLAN; N. P. JONES

1999-01-01

79

GHM: A generalized Hamiltonian method for passivity test of impedance\\/admittance descriptor systems  

Microsoft Academic Search

A generalized Hamiltonian method (GHM) is proposed for passivity test of descriptor systems (DSs) which describe impedance or admittance input-output responses. GHM can test passivity of DSs with any system index without minimal realization. This frequency-independent method can avoid the time-consuming system decomposition as required in many existing DS passivity test approaches. Furthermore, GHM can test systems with singular D

Chi-Un Lei; Ngai Wong; Ngai Wong

2009-01-01

80

Current Loop Control with Admittance Compensation for a Single-Phase Grid-Tie Fuel Cell Power Conditioning System  

Microsoft Academic Search

Current loop transfer function of a single-phase grid-tie inverter has been systematically derived with representations of conventional transfer function format and admittance terms for the sake of controller design and feed-forward compensation. A 5 kW grid-tie fuel cell power conditioning system (PCS) example is used in paper to show current loop controller design and admittance compensation technique. A second order

Sung-Yeul Park; Jih-Sheng Lai; Chien-Liang Chen; Seung-Ryul Moon; Tae-Won Chun

2007-01-01

81

Left ventricular epicardial admittance measurement for detection of acute LV dilation.  

PubMed

There are two implanted heart failure warning systems incorporated into biventricular pacemakers/automatic implantable cardiac defibrillators and tested in clinical trials: right heart pressures, and lung conductance measurements. However, both warning systems postdate measures of the earliest indicator of impending heart failure: left ventricular (LV) volume. There are currently no proposed implanted technologies that can perform LV blood volume measurements in humans. We propose to solve this problem by incorporating an admittance measurement system onto currently deployed biventricular and automatic implantable cardiac defibrillator leads. This study will demonstrate that an admittance measurement system can detect LV blood conductance from the epicardial position, despite the current generating and sensing electrodes being in constant motion with the heart, and with dynamic removal of the myocardial component of the returning voltage signal. Specifically, in 11 pigs, it will be demonstrated that 1) a physiological LV blood conductance signal can be derived; 2) LV dilation in response to dose-response intravenous neosynephrine can be detected by blood conductance in a similar fashion to the standard of endocardial crystals when admittance is used, but not when only traditional conductance is used; 3) the physiological impact of acute left anterior descending coronary artery occlusion and resultant LV dilation can be detected by blood conductance, before the anticipated secondary rise in right ventricular systolic pressure; and 4) a pleural effusion simulated by placing saline outside the pericardium does not serve as a source of artifact for blood conductance measurements. PMID:21148342

Porterfield, John E; Larson, Erik R; Jenkins, James T; Escobedo, Daniel; Valvano, Jonathan W; Pearce, John A; Feldman, Marc D

2010-12-09

82

Characterization of Heterogeneously Nucleated Phase Transformations and Characterization of Associated Microstructures.  

National Technical Information Service (NTIS)

Homogeneous and grain boundary heterogeneous nucleation and growth phase transformation processes have been shown to follow four distinct types of kinetic behavior. Kinetics are determined by processing treatment, interfacial and grain boundary energies, ...

J. E. Sanchez

1976-01-01

83

Localization and Characterization of the Carbon Tetrachloride Transformation Activity of Pseudomonas sp. Strain KC  

PubMed Central

Previous research has established that Pseudomonas sp. strain KC rapidly transforms carbon tetrachloride (CT) to carbon dioxide (45 to 55%), a nonvolatile fraction (45 to 55%), and a cell-associated fraction ((equiv)5%) under denitrifying, iron-limited conditions. The present study provides additional characterization of the nonvolatile fraction, demonstrates that electron transfer plays a role in the transformation, and establishes the importance of both extracellular and intracellular factors. Experiments with (sup14)C-labeled CT indicate that more than one nonvolatile product is produced during CT transformation by strain KC. One of these products, accounting for about 20% of the [(sup14)C]CT transformed, was identified as formate on the basis of its elution time from an ion-exchange column, its boiling point, and its conversion to (sup14)CO(inf2) when incubated with formate dehydrogenase. Production of formate requires transfer of two electrons to the CT molecule. The role of electron transfer was also supported by experiments demonstrating that stationary-phase cells that do not transform CT can be stimulated to transform CT when supplemented with acetate (electron donor), nitrate (electron acceptor), or a protonophore (carbonyl cyanide m-chlorophenylhydrazone). The location of transformation activity was also evaluated. By themselves, washed cells did not transform CT to a significant degree. Occasionally, CT transformation was observed by cell-free culture supernatant, but this activity was not reliable. Rapid and reliable CT transformation was only obtained when washed whole cells were reconstituted with culture supernatant, indicating that both extracellular and intracellular factors are normally required for CT transformation. Fractionation of culture supernatant by ultrafiltration established that the extracellular factor or factors are small, with an apparent molecular mass of less than 500 Da. The extracellular factor or factors were stable after lyophilization to powder and were extractable with acetone. Addition of micromolar levels of iron inhibited CT transformation in whole cultures, but the level of iron needed to inhibit CT transformation was over 100-fold higher for washed cells reconstituted with a 10,000-Da supernatant filtrate. Thus, the inhibitory effects of iron are exacerbated by a supernatant factor or factors with a molecular mass greater than 10,000 Da.

Dybas, M. J.; Tatara, G. M.; Criddle, C. S.

1995-01-01

84

Three-phase backward\\/forward power flow solution considering three-phase distribution transformers  

Microsoft Academic Search

This paper proposes a three-phase backward\\/forward power flow solution which can handle distribution transformers of various common winding connections in unbalanced system of multi voltage levels. The proposed algorithm is based on the power summation method and takes the power losses into account considering the mutual coupling between three phases. The transformers are modeled by transformer nodal admittance matrix and

Elahe Mashhour; S. M. Moghaddas-Tafreshi

2009-01-01

85

Fault analysis of Un-transposed three-phase based on Fortescue transformation matrix  

Microsoft Academic Search

Fortescue's transformation is a well-known matrix which can be used for fault analysis of perfectly transposed three- phase lines, but for un-transposed asymmetrical transmission lines, the parameter matrices of line such as impedance matrix and admittance matrix are no longer circulant matrices, It means that the Fortescue transformation matrix can not digitalization of the parameters. Nevertheless, the transformation matrix can

Bo Liu; Qingchao Zhang

2011-01-01

86

Positive screening and transformation of ura5 mutants in the fungus Podospora anserina : characterization of the transformants  

Microsoft Academic Search

To develop a transformation system in the filamentous fungus Podospora anserina we have selected ura5 mutants deficient in orotidylic acid pyrophosphorylase using a positive screening. These mutants could be transformed to prototrophy by an hybrid vector carrying the ura5 gene of this organism. The properties of the transformants have been analysed. In most cases integration of the transforming vector occurred

V. Razanamparany; J. Bégueret

1986-01-01

87

Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.

Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas

2009-06-01

88

Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform  

SciTech Connect

The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.

Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas [Laboratory for Gravitational Physics, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Starodub, Incorporated, 3504 Littledale Road, Kensington, Maryland, 20895 (United States)

2009-06-15

89

Construction and physiological characterization of glyceraldehyde-3-phosphate dehydrogenase overproducing transformants of Aspergillus nidulans.  

PubMed

The construction and characterization of glyceraldehyde-3-phosphate-dehydrogenase (GPD) overproducing transformants of Aspergillus nidulans and their behaviour in acetate-limited continuous cultures and glucose-grown batch cultures are described. The A. nidulans acetamidase deletion strain MH1277 was transformed with the homologous gpdA gene on a vector with the homologous acetamidase-gene (amdS) as a selection marker. Transformant A1 contains about nine integrated copies of the gpdA gene, and shows a proportional gene-dosage GPD production of about 22% of the total soluble cell protein. Compared to the wild-type MH1277, A1 has higher growth yields and reaches higher specific growth rates on both acetate and glucose, which could be due to the key position of GPD in glycolysis and gluconeogenesis. PMID:1367201

Hanegraaf, P P; Punt, P J; van den Hondel, C A; Dekker, J; Yap, W; van Verseveld, H W; Stouthamer, A H

1991-03-01

90

Chemically functionalized carbon nanotubes and their characterization using thermogravimetric analysis, fourier transform infrared, and raman spectroscopy  

Microsoft Academic Search

This article reports key findings on the chemical functionalization of carbon nanotubes (CNT). The functionalization of chemical\\u000a vapor-deposited CNT was carried out by treating tubes with polyvinyl alcohol through ultrasonication in water with the aid\\u000a of a surfactant. The surfactant is expected to promote the unbundling of aggregated CNT. The characterization of functionalized\\u000a samples using thermogravimetric analysis, Fourier transform infrared

E. Titus; N. Ali; G. Cabral; J. Gracio; P. Ramesh Babu; M. J. Jackson

2006-01-01

91

In situ semiconductor materials characterization by emission Fourier transform infrared spectroscopy  

Microsoft Academic Search

The results of a novel emission Fourier transform infrared (E\\/FT-IR) spectrometer for in-situ characterization of semiconductor materials is presented. For the experiments, the wafers were heated and the infrared emission profiles from the substrates were collected by a standard FT-IR spectrometer. Differences in the emission spectra from different substrates are explained through correlation to the optical properties of the corresponding

Zhen-Hong Zhou; Senja Compton; Isabel Yang; Rafael Reif

1994-01-01

92

Characterization of the transformations of lignocellulosic structures upon degradation in planted soil  

Microsoft Academic Search

Analytical pyrolysis (AP) as well as chemical analysis, ESR, FTIR and UV\\/VIS-spectroscopy has been used to characterize effects of modification of industrial lignins (hydrolysis lignin and kraft lignin) with silicon-containing oligomers on their transformation in soil planted with timothy grass (Phleum pratense). Using Py-GC\\/MS it was shown that carbohydrate-originated admixtures of non-modified hydrolysis lignin were degraded preferentially during the first

G. Telysheva; G. Dobele; D. Meier; T. Dizhbite; G. Rossinska; V. Jurkjane

2007-01-01

93

Characterization and application of fusidane antibiotic biosynethsis enzyme 3-ketosteroid-?1-dehydrogenase in steroid transformation.  

PubMed

Microbial ?(1)-dehydrogenation is one of the most important transformations in the synthesis of steroid hormones. In this study, a 3-ketosteroid-?(1)-dehydrogenase (kstD(F)) involved in fusidane antibiotic biosynthesis from Aspergillus fumigatus CICC 40167 was characterized for use in steroid transformation. KstD(F) encodes a polypeptide consisting of 637 amino acid residues. It shows 51% amino acid identity with a kstD from Thermomicrobium roseum DSM 5159. Expression of kstD(F) in Escherichia coli and Pichia pastoris showed that all kstD(F) activity is located in the cytoplasm. This indicates that it is a soluble intracytoplasmic enzyme, unlike most kstDs from bacteria, which are membrane-bound. The expression of kstD(F) was performed in P. pastoris, both intracellularly and extracelluarly. The intracellularly expressed protein displayed good activity in steroid transformation, while the extracellularly expressed protein showed nothing. Interestingly, the engineered P. pastoris KM71 (KM71(I)) and GS115 (GS115(I)) showed different transformation activities for 4-androstene-3,17-dione (AD) when kstD(F) was expressed intracellularly. Under the same conditions, KM71(I) was found capable of transforming 1.0 g/l AD to 1,4-androstadiene-3,17-dione (ADD), while GS115(I) could transform 1.5 g/l AD to both ADD and boldenone (BD). The production of BD is attributed to a 17?-hydroxysteroid dehydrogenase in P. pastoris GS115(I), which catalyzes the reversible reaction between C17-one and C17-alcohol of steroids. The conversion of AD by GS115(I) and KM71(I) may provide alternative means of preparing ADD or BD. In brief, we show here that kstD(F) is a promising enzyme in steroid ?(1)-dehydrogenation that is propitious to construct genetically engineered steroid-transforming recombinants by heterologous overexpression. PMID:22234537

Chen, Miao-Miao; Wang, Feng-Qing; Lin, Liang-Cai; Yao, Kang; Wei, Dong-Zhi

2012-01-11

94

Admittance-based pressure-volume loop measurements in a porcine model of chronic myocardial infarction.  

PubMed

The aim of this study was to validate admittance-based pressure-volume (PV) loop measurements for the assessment of cardiac function in a porcine model of chronic myocardial infarction. The traditional PV loop measurement technique requires hypertonic saline injections for parallel conductance correction prior to signal conversion into volume. Furthermore, it assumes a linear relationship between conductance and volume. More recently, an admittance-based technique has been developed, which continuously measures parallel conductance and uses a non-linear equation for volume calculation. This technique has not yet been evaluated in a large-animal model of myocardial ischaemia. Eleven pigs underwent invasive PV measurements with the admittance system (AS) and the traditional conductance system followed by three-dimensional echocardiography (3DE). After baseline measurements, pigs were subjected to 90 min left anterior descending coronary artery occlusion, followed by the same measurements at 8 weeks follow-up. In the healthy heart, the AS showed good agreement with 3DE for left ventricular volumes and a reasonable correlation for ejection fraction (r = 0.756, P = 0.007). At follow-up, an increase in end-systolic volume was observed with 3DE (+15.4 ± 14.4 ml, P = 0.005) and the AS (+34.6 ± 36.1 ml, P = 0.010). The ejection fraction measured with 3DE (-13.2 ± 5.2%, P < 0.001) and the AS (-20.3 ± 11.2%, P < 0.001) significantly decreased. We conclude that the AS can be used for quantitative monitoring of changes in cardiac function induced by myocardial infarction and provides comparable results to 3DE, rendering it a useful tool for functional testing in large-animal cardiac models. PMID:23955306

van Hout, G P J; de Jong, R; Vrijenhoek, J E P; Timmers, L; Duckers, H J; Hoefer, I E

2013-08-16

95

Admittance Test and Conceptual Study of a CW Positron Source for CEBAF  

SciTech Connect

A conceptual study of a Continuous Wave (CW) positron production is presented in this paper. The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB) operates with a CW electron beam with a well-defined emittance, time structure and energy spread. Positrons created via bremsstrahlung photons in a high-Z target emerge with a large emittance compared to incoming electron beam. An admittance study has been performed at CEBAF to estimate the maximum beam phase space area that can be transported in the LINAC and in the Arcs. A positron source is described utilizing the CEBAF injector electron beam, and directly injecting the positrons into the CEBAF LINAC.

Golge, Serkan [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Hyde, Charles E. [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Universite Blaise Pascal, Clermont-Ferrand (France); Freyberger, Arne [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

2009-09-02

96

Investigation of hole-mobility in a polyfluorene copolymer by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

Transport of holes in a low band gap polyfluorene, APFO-Green6, was investigated by means of admittance spectroscopy in the modulation frequency range 1-106 Hz. At room temperature, hole mobility of APFO-Green6 is dependent on the applied electric field, as commonly observed in disordered organic materials. The excess capacitance toward low frequencies provides evidence for charge relaxation in trap levels. A dispersion parameter of 0.4 was achieved from the trend of hole transit times with the electric field.

Debebe, Siraye E.; Mammo, Wendimagegn; Yohannes, Teketel; Tinti, Francesca; Zanelli, Alberto; Camaioni, Nadia

2010-02-01

97

Characterization and immunotherapeutic potential of a monoclonal antibody against a ras oncogene transformed cell line  

SciTech Connect

Transformed cells express cell surface antigens not present, or present in diminished amounts on normal cells. Monoclonal antibodies can be used to identify and biochemically characterize tumor-associated antigens. Monoclonal antibody (MoAb) 45-2D9 was produced by immunization of BALB/c mice with a transformed cell line (45-2D9) induced by transfection of NIH 3T3 cells with a c-H-ras oncogene in DNA isolated from a human lung carcinoma. By immunoperoxidase staining, this antibody binds to the 45-342 cells as well as to the ras transformed primary and 3 secondary transfectants, including the one used to induce 45-342, but not to other ras transformed cell lines. Murine tumors as well as human fetal and most normal adult tissues are not stained. This antibody does bind to a variety of human tumors, including lung adenocarcinomas, as well as breast, colon and esophageal carcinomas. The ability of MoAb 45-2D9 to target ricin toxin A chain (RTA) and radio-isotopes to gp74 expressing cells was investigated. An immunotoxin generated by conjugating RTA to MoAb 45-2D9 inhibits protein and DNA synthesis by the 45-342 cells. Radiolabeled antibody specifically localizes to and can be used to image subcutaneous and pulmonary gp74 expressing tumors in nu/nu mice. Monoclonal antibodies against oncogene transformed cell lines may be useful for the detection and characterization of tumor-associated antigens as well as for the development of new tumor therapeutic and diagnostic reagents.

Ames, R.S. Jr.

1986-01-01

98

Polarization averaged short-time Fourier transform technique for distributed fiber birefringence characterization using Brillouin gain.  

PubMed

A polarization averaged short-time Fourier transform (PASTFT) technique is developed for distributed fiber birefringence characterization based on counterpropagating stimulated Brillouin scattering (SBS) gain signal. This technique can be used for the birefringence characterization of the general elliptical birefringent fiber. A theoretical model on polarization matching of counterpropagating SBS process is established. The performance of the short-time Fourier transform (STFT) method and the PASTFT technique is analyzed by using the simulation of the theoretical model. Simulation results show that the process of polarization average could effectively reduce the birefringence characterization error caused by the polarization dependence of the local period of SBS gain. A less than 8% normalized root mean square error is achieved for the characterization of the length of the birefringence vector on elliptical birefringent fibers. The PASTFT technique is experimentally verified by the distributed measurement of beat length and differential group delay of a standard single-mode fiber via the Brillouin optical time domain analysis system. PMID:22772108

Xie, Shangran; Chen, Liang; Bao, Xiaoyi

2012-07-01

99

Transformations  

NASA Astrophysics Data System (ADS)

Hot-dip galvanized drawing quality special killed (DQSK) steel and titanium stabilized interstitial free (IF) steel substrates were annealed under varying temperature and time conditions in order to characterize the coating structure development which occurs during the annealing portion of the galvannealing process. Through the use of light optical microscopy, the coating morphology development (Fe-Zn alloy layer growth) observed in cross section on both substrates was defined in three distinct stages. The three characteristic microstructures were classified as type 0 (underalloyed), type 1 (marginally alloyed), and type 2 (overalloyed) morphologies. The morphology transitions were quantitatively defined by total iron content in the coating and by the thickness of an interfacial Fe-Zn gamma phase layer. The DQSK steel coating type 1 to type 2 morphology transition occurred at an iron content of 9 to 10 wt Pct. For the titanium IF material, the same type 1 to type 2 morphology transition occurred at an iron content of 10.5 to 11.5 wt Pct and at an interfacial layer thickness of approximately 1.0 µm. An increased amount of aluminum in the galvanizing bath delayed the alloying reaction during galvannealing for both substrates. The overall inhibition effect of aluminum was less pronounced on the titanium stabilized IF material, indicating that its coating alloying kinetics were not as significantly influenced by bath aluminum content.

Jordan, C. E.; Marder, A. R.

1994-05-01

100

Josephson admittance spectroscopy application for frequency analysis of broadband THz antennas  

NASA Astrophysics Data System (ADS)

Application of Josephson admittance spectroscopy for the spectral analysis of a broad-band log-periodic superconducting antenna was demonstrated at the frequency range from 50 to 700 GHz. The [001]-tilt YBa2Cu3O7-x bicrystal Josephson junctions, integrated with sinuous log-periodic YBa2Cu3O7-x antennas, were fabricated on NdGaO3 bicrystal substrates. A real part of the antenna admittance ReY(f) as a function of the frequency f was reconstructed from the modification of the dc current-voltage characteristic of the junction, induced by the antenna. Resonance features were observed in the recovered ReY(f)-spectra with a periodicity in the logarithmic frequency scale, corresponding to log-periodic geometry of the antenna. The ReY(f)-spectra, recovered by Josephson spectroscopy, were compared with the ReY(f)-spectra, obtained by CAD simulation, and both spectra were shown to be similar in their main features. A value of 23 was obtained for an effective permittivity of the NdGaO3 bicrystal substrates by fitting simulated data to those obtained from Josephson spectroscopy.

Volkov, O. Yu; Divin, Yu Yu; Gubankov, V. N.; Gundareva, I. I.; Pavlovskiy, V. V.

2010-06-01

101

Magnetic resonance imaging characterization of hemorrhagic transformation of embolic stroke in the rat.  

PubMed

Intracranial hemorrhage is a critical factor when considering efficacy and safety of thrombolytic intervention after thromboembolic stroke. This study tested whether magnetic resonance imaging could identify tissue for hemorrhagic transformation after the onset of embolic stroke. Rats subjected to embolic stroke with and without recombinant tissue-type plasmogen activator (rt-PA) treatment were followed-up with magnetic resonance imaging using the inverse of the apparent forward transfer rate for magnetization transfer (k(inv)), gadolinium-chelate contrast-enhanced magnetic resonance imaging, and diffusion-, perfusion-, and T2-weighted imaging. Rats with embolic stroke either were treated with rt-PA 1 (n = 16) or 4 hours (n = 13) after stroke onset or were not treated (n = 15). From these groups, at total of 17 rats had intracerebral hemorrhage. Tissue progressing to hemorrhage and adjacent to the site of hemorrhage was analyzed to identify magnetic resonance imaging markers that characterize hemorrhagic transformation. The parameter maps of k(inv) and contrast-enhanced magnetic resonance imaging showed greater sensitivity in the detection of tissue destined for hemorrhagic transformation compared with the apparent diffusion coefficient of water (ADCw) and CBF. In tissue not destined to undergo hemorrhagic transformation, k(inv) maps and contrast-enhanced magnetic resonance imaging exhibited small increases in k(inv) and contrast-enhanced magnetic resonance imaging signal intensity in the area encompassing the territory supplied by the middle cerebral artery. In contrast, large increases in k(inv) and in signal intensity in the contrast-enhanced magnetic resonance images were detected in the region where gross hemorrhage was confirmed histologically. The values of k(inv), T2, and signal intensity in the contrast-enhanced magnetic resonance images were significantly higher in the region destined for hemorrhagic transformation (k(inv), P < or = 0.033 3-24 hours after embolization; T2, P < or = 0.037 24-48 hours; contrast-enhanced magnetic resonance imaging, P < 0.05 4-7 hours) compared with the nonhemorrhagic transformation ischemic region or in the contralateral homologous regions after onset of ischemia. Of these methods, k(inv) shows the most sensitivity in the detection of hemorrhagic transformation soon after embolization. The authors' data suggest that k(inv) and contrast-enhanced magnetic resonance imaging are potentially important methodologies for detecting tissue destined for hemorrhagic transformation. PMID:11973428

Jiang, Quan; Zhang, Rui Lan; Zhang, Zheng Gang; Knight, Robert A; Ewing, James R; Ding, GuangLiang; Lu, Mei; Arniego, Polly; Zhang, Li; Hu, Jiani; Li, QingJiang; Chopp, Michael

2002-05-01

102

Microstructural characterization of transformable Fe-Mn alloys at different length scales  

SciTech Connect

The as-annealed and deformed Microstructure of transformable Fe-Mn alloys were, comprehensively, characterized over a wide range of length scales. Differential interference contrast optical metallography, combined with a tinting etching method, was employed to examine the grain morphology. A new specimen preparation method, involving electro-polishing and electro-etching, was developed for scanning electron microscopy and electron back-scattered diffraction analysis. This method leads to a very good imaging contrast and thus bridges the length scale gap between optical metallography and transmission electron microscopy. Moreover, it enables simultaneous scanning electron microscopy and electron backscatter diffraction analysis which allows correlations among morphology, crystal orientation and phase analysis in the length scale of microns. Transmission electron microscopy investigations were also made to evaluate the thermal and mechanical transformation products as well as defect structures.

Liang, X.; Wang, X. [Department of Materials Science and Engineering, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4L7 (Canada); Zurob, H.S., E-mail: zurobh@mcmaster.ca [Department of Materials Science and Engineering, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4L7 (Canada)

2009-11-15

103

Characterization of Solid State Phase Transformation in Continuously Heated and Cooled Ferritic Weld Metal  

SciTech Connect

Arc welding processes involve cooling rates that vary over a wide range (1-100 K/s). The final microstructire is thus a product of the heating and cooling cycles experienced by the weld in addition to the weld composition. It has been shown that the first phase to form under weld cooling conditions may not be that predicted by equilibrium calculations. The partitioning of different interstitial/substitutional alloying elements at high temperatures can dramatically affect the subsequent phase transformations. In order to understand the effect of alloying on phase transformation temperatures and final microstructures time-resolved X-ray diffraction technique has been successfully used for characterization. The work by Jacot and Rappaz on pearlitic steels provided insight into austenitization of hypoeutectic steels using a finite volume model. However there is very little work done on the effect of heating and cooling rates on the phase transformation paths in bainitic/martensitic steels and weld metals. Previous work on a weld with higher aluminum content, deposited with a FCAW-S process indicated that even at aluminum levels where the primary phase to solidify from liquid should be delta ferrite, non-equilibrium austenite was observed. The presence of inhomogeneity in composition of the parent microstructure has been attributed to differences in transformation modes, temperatures and microstructures in dual-phase, TRIP steels and ferritic welds. The objectives of the work included the identification of the stability regions of different phases during heating and cooling, differences in the effect of weld heating and cooling rates on the phase transformation temperatures, and the variation in phase fractions of austenite and ferrite in the two phase regions as a function of temperature. The base composition used for the present work is a Fe-1%Al-2%Mn-1%Ni-0.04%C weld metal. A pseudo-binary phase diagram shows the expected solidification path under equilibrium conditions. However, the effect of heating and cooling rates on the phase transformation path due to non-equilibrium partitioning of alloying elements cannot be predicted by equilibrium phase diagrams. Also, it is unclear if there is retention of delta ferrite to room temperature due to compositional or thermal effects. This would dramatically affect the austenite to ferrite transformation due to carbon and nitrogen enrichment in the austenite.

Narayana, B [Ohio State University, The, Columbus; Mills, Michael J. [Ohio State University, The, Columbus; Specht, Eliot D [ORNL; Santella, Michael L [ORNL; Babu, Sudarsanam Suresh [Ohio State University, The, Columbus

2010-12-01

104

Chinchilla middle-ear admittance and sound power: high-frequency estimates and effects of inner-ear modifications.  

PubMed

The middle-ear input admittance relates sound power into the middle ear (ME) and sound pressure at the tympanic membrane (TM). ME input admittance was measured in the chinchilla ear canal as part of a larger study of sound power transmission through the ME into the inner ear. The middle ear was open, and the inner ear was intact or modified with small sensors inserted into the vestibule near the cochlear base. A simple model of the chinchilla ear canal, based on ear canal sound pressure measurements at two points along the canal and an assumption of plane-wave propagation, enables reliable estimates of Y(TM,) the ME input admittance at the TM, from the admittance measured relatively far from the TM. Y(TM) appears valid at frequencies as high as 17 kHz, a much higher frequency than previously reported. The real part of Y(TM) decreases with frequency above 2 kHz. Effects of the inner-ear sensors (necessary for inner ear power computation) were small and generally limited to frequencies below 3 kHz. Computed power reflectance was ~0.1 below 3.5 kHz, lower than with an intact ME below 2.5 kHz, and nearly 1 above 16 kHz. PMID:23039439

Ravicz, Michael E; Rosowski, John J

2012-10-01

105

Chinchilla middle-ear admittance and sound power: High-frequency estimates and effects of inner-ear modifications  

PubMed Central

The middle-ear input admittance relates sound power into the middle ear (ME) and sound pressure at the tympanic membrane (TM). ME input admittance was measured in the chinchilla ear canal as part of a larger study of sound power transmission through the ME into the inner ear. The middle ear was open, and the inner ear was intact or modified with small sensors inserted into the vestibule near the cochlear base. A simple model of the chinchilla ear canal, based on ear canal sound pressure measurements at two points along the canal and an assumption of plane-wave propagation, enables reliable estimates of YTM, the ME input admittance at the TM, from the admittance measured relatively far from the TM. YTM appears valid at frequencies as high as 17 kHz, a much higher frequency than previously reported. The real part of YTM decreases with frequency above 2 kHz. Effects of the inner-ear sensors (necessary for inner ear power computation) were small and generally limited to frequencies below 3 kHz. Computed power reflectance was ?0.1 below 3.5?kHz, lower than with an intact ME below 2.5?kHz, and nearly 1 above 16?kHz.

Ravicz, Michael E.; Rosowski, John J.

2012-01-01

106

Optical Fourier transform based in-plane vibration characterization for MEMS comb structure.  

PubMed

On-line and on-wafer characterizations of mechanical properties of Micro-Electro-Mechanical-System (MEMS) with efficiency are very important to the mass production of MEMS foundry in the near future. However, challenges still remain. In this paper, we present an in-plane vibration characterizing method for MEMS comb using optical Fourier transform (OFT). In the experiment, the intensity distribution at the focal plane was captured to characterize the displacement of the vibrator in the MEMS comb structure. A typical MEMS comb was tested to verify the principle. The shape and the movement of MEMS comb was imitated and tested to calibrate the measurement by using a spatial light modulator (SLM). The relative standard deviations (RSD) of the measured displacements were better than 5%, where the RSD is defined as the ratio of the standard deviation to the mean. It is convinced that the presented method is feasible for on-line and on-wafer characterizations for MEMS with great convenience, high efficiency and low cost. PMID:23482039

Gao, Yongfeng; Cao, Liangcai; You, Zheng; Zhao, Jiahao; Zhang, Zichen; Yang, Jianzhong

2013-02-25

107

Localized Gravity/Topography Correlation and Admittance Spectra one the Moon  

NASA Astrophysics Data System (ADS)

Lunar surface and structure can be separate into two parts. The lunar near side crust and far side crust differ remarkably in thickness. This difference probably caused by difference of thermal evolution and state (elastic thickness) and catering history on both side. The correlations and admittance between the topography and gravity anomalies provide important information on the level of isostatic compensation of the lithosphere at the geological timescale, and reflect its thermo-mechanical state. Therefore, localized correlation and admittance analysis is one of the most important studies of selenodesy. A global correlation between topography and gravity of the Moon obtained by Clementine and Lunar Prospector missions, respectively, reveals high value at long wavelength and low value at short wavelength. Such characteristics are distinguished from those of the Earth and other terrestrial planets, whose global correlation between topography and gravity is low at long wavelength. The distinct correlation between topography and gravity of the Moon may indicate that the lunar topography is supported by multiple compensation mechanism. Further, an incomplete coverage of Doppler tracking data prior to Kaguya (SELENE) gravity experiment probably contributed to the correlation. Because the Moon is synchronously rotating with its revolution around the Earth, a spacecraft orbiting over the far side is not visible from ground stations. In either case, it is significant to decompose local correlation from global ones in order to investigate internal structure of the Moon from spherical harmonic model of gravity (LP75G [1]) and topography (GLTM-2 [2]). Japanese lunar exploration Kaguya (SELENE) has two kinds of selenodesical experiments. One is RSAT/VRAD (gravity mapping with direct tracking over far-side) experiment and another is Laser ALTimeter (LALT; topography mapping) experiment. These two experiments enable us to conduct localized analysis for the Moon. Therefore we attempt localized spectral analysis of the Moon first and then apply possible compensation mechanisms to explain the observed admittance. Kaguya mission has been yielding representation of lunar gravity and topography (shape) substantially superior in resolution and accuracy to earlier solutions. For global lunar gravity field, an accurate spherical harmonic model of gravitational potential up to degree and order 100 (SGM100g) was derived from one year tracking (including 4-way Doppler) data [3]. For topography, LALT has obtained more than 6 million altitude measurements with 5 m precision, from which a spherical harmonic expansion of topography to degree and order 359 (STM359_grid-02) has been determined [4]. In this study, we use those new models. We employ the spatio-spectral localization technique [5] to obtain gravity/shape correlation and admittance spectra as function of position on the Moon. In this analysis, we localize harmonic field with axisymmetric windows of constant diameter, described by Lwin zonal harmonic coefficients. This restricts the permissible range of l in the windowed fields at both the low- (l > Lwin) and high-wave number ends (l < Lobs-Lwin, ; Lobs is the maximum degree of observation) . We chose four fixed windows with Lwin = 5, 10, 17, 26 (equivalent to spatial scales 2200, 1100, 640 and 420 km, respectively). These window sizes correspond to huge-, large-, middle-, and small-size of impact basins. For up to degree 50 with Lwin = 5 scale, it is clearly shown that the near-side contains distinct anti-correlation regions whereas the far-side is mostly occupied by high correlation regions. This difference is mainly due to large mascon basins in near-side, such as mare Imbrium. For Lwin = 10 and 17 scales, we can see anti-correlation regions at not only near-side but also far-side. Locations of anti-correlation regions in the far-side correspond to impact basins (Type II basin [6]). However, lots of far side basins (Type I basin [6]) are not indicated by anti-correlations for these window sizes. For Lwin = 26 scale, we can see we

Ishihara, Y.; Namiki, N.; Sugita, S.; Matsumoto, K.; Goossens, S.; Araki, H.; Noda, H.; Sasaki, S.; Iwata, T.; Hanada, H.

2009-04-01

108

Application of the A.C. Admittance technique to double layer studies on polycrystalline gold electrodes  

NASA Astrophysics Data System (ADS)

A detailed examination of the dependence of the a.c. admittance of a cell containing a polycrystalline gold electrode has been made in the double layer region as a function of d.c. potential, a.c. frequency, and electrode history. It is shown that the interfacial impedance of a gold electrode with a carefully prepared surface can be treated under these circumstances as a constant phase element when it is in contact with an aqueous solution containing 0.05 M KClO4. Analysis of the frequency dependence of the cell impedance gives the surface inhomogeneity parameter n which turns out to be very close to unity. Although the electrode surface is only slightly inhomogeneous on a microscopic scale, a very large frequency dispersion of the impedance is observed experimentally. A method of estimating the true specific capacity of the electrode is presented, and conditions for carrying out the experiments in a reproducible manner are discussed.

Fawcett, W. R.; Kovacova, Zuzana; Motheo, Arthur J.; Foss, Colby A., Jr.

1992-02-01

109

Determination of electron mobility in tris(8-hydroxy-quinolinato) aluminum by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

The electron mobilities of tris(8-hydroxy-quinolinato) aluminum (Alq3) thin films at various thicknesses (70-280 nm) have been determined by using admittance spectroscopy measurements. Our results show that the electric field dependence of electron mobilities exhibits different behaviors at different thicknesses of Alq3 films. Clearly, when the thickness of Alq3 film is less than 150 nm, the electron mobilities slightly decrease with increasing the electric field. For the thickness of Alq3 film more than 150 nm, however, the mobilities increase as the electric field increases. The phenomena are well discussed by energetic disorder. Using temperature dependent I-V characteristics, we further calculated the density of traps.

Wang, Yanping; Chen, Jiangshan; Dong, Lisong; Ma, Dongge

2013-09-01

110

Bias stress instability in organic transistors investigated by ac admittance measurements  

NASA Astrophysics Data System (ADS)

In this paper, the bias stress effect (BSE) in organic field-effect transistors has been analyzed by an alternative experimental approach based on ac admittance (Y=G+j?C) measurements. conductance (C) and capacitance (G) curves have been recorded as a function of frequency at different times of the bias stress experiments and simultaneously fitted through a transmission line circuit, able to separately model the conducting properties of the channel and contact regions. The determination of the time behavior of the model fitting parameters is assumed as the starting point for a quantitative analysis of the BSE occurrence. This experimental procedure clarifies that both channel resistance (Rch) and contact resistance (Rc) are largely affected by the BSE, while the channel capacitance (Cch), related to the charge accumulation sheet, and the contact capacitance (Cc) result almost unchanged.

di Girolamo, F. V.; Barra, M.; Capello, V.; Oronzio, M.; Romano, C.; Cassinese, A.

2010-06-01

111

High density trans-admittance mammography development and preliminary phantom tests  

PubMed Central

Background Malignant breast tumor tissue has a significantly different electrical impedance spectrum than surrounding normal tissues. This has led to the development of impedance imaging as a supplementary or alternative method to X-ray mammography for screening and assessment of breast cancers. However low spatial resolution and poor signal to noise ratio has limited the clinical application. Methods In order to improve spatial resolution we developed a trans-admittance mammography (TAM) system including an array of 60×60 current sensing electrodes. We adopted a similar setup to X-ray mammography where the breast is situated between two holding plates. The top plate is a large solid metal electrode for applying a sinusoidal voltage over a range of frequencies from 50 Hz to 500 kHz. The bottom plate has 3600 current sensing electrodes that are kept at the ground potential. Currents are generated from the top voltage-applying electrode and spread throughout the breast, entering the TAM system through the array of current sensing electrodes on the bottom plate. The TAM system measures the exit currents through 6 switching modules connected to 600 electrodes each. Each switching module is connected to 12 ammeter channels which are switched sequentially to 50 of the 600 electrodes each measurement time. Each ammeter channel is comprised of a current-to-voltage converter, a gain amplifier, filters, an analog to digital converter, and a digital phase sensitive demodulator. Results We found an average noise level of 38 nA, amplitude stability of less than 0.2%, crosstalk of better than -60 dB and 70 dB signal to noise ratio over all channels and operating frequencies. Images were obtained in time difference and frequency difference modes in a saline phantom. Conclusion We describe the design, construction, and calibration of a high density TAM system in detail. Successful high resolution time and frequency difference images showed regions of interest with the expected admittivity changes in the frequency spectrum.

2012-01-01

112

The effect of flying and low humidity on the admittance of the tympanic membrane and middle ear system.  

PubMed

Many passengers experience discomfort during flight because of the effect of low humidity on the skin, eyes, throat, and nose. In this physiological study, we have investigated whether flight and low humidity also affect the tympanic membrane. From previous studies, a decrease in admittance of the tympanic membrane through drying might be expected to affect the buffering capacity of the middle ear and to disrupt automatic pressure regulation. This investigation involved an observational study onboard an aircraft combined with experiments in an environmental chamber, where the humidity could be controlled but could not be made to be as low as during flight. For the flight study, there was a linear relationship between the peak compensated static admittance of the tympanic membrane and relative humidity with a constant of proportionality of 0.00315 mmho/% relative humidity. The low humidity at cruise altitude (minimum 22.7 %) was associated with a mean decrease in admittance of about 20 % compared with measures in the airport. From the chamber study, we further found that a mean decrease in relative humidity of 23.4 % led to a significant decrease in mean admittance by 0.11 mmho [F(1,8)?=?18.95, P?=?0.002], a decrease of 9.4 %. The order of magnitude for the effect of humidity was similar for the flight and environmental chamber studies. We conclude that admittance changes during flight were likely to have been caused by the low humidity in the aircraft cabin and that these changes may affect the automatic pressure regulation of the middle ear during descent. PMID:23887775

Morse, Robert Peter

2013-07-26

113

Three-phase transformer models for load flow calculations in power systems  

Microsoft Academic Search

Transformer models are important in performing load flow procedure, especially in distribution power systems. This paper summarizes the detailed transformer models with various connection types using phase coordinates, such as two-winding transformers, open wye-delta with a mid-tap grounded on the secondary side and other special connection types. But in some conditions, the nodal admittance submatrices of these transformers become singular

Jun Kang; Lijun Fu

2008-01-01

114

Thin multilayers characterization by grazing X-ray reflectometry and use of Fourier transform  

NASA Astrophysics Data System (ADS)

Grazing X-ray reflectometry is used in order to characterize thin layer stacks, in particular periodic multilayers. The specular reflectivity depends on the thickness, the complex refractive index of each layer and on the roughness of the interfaces. By a trial and error method, the experimental reflectivity curve can be fitted with a theoretical one, and so, the parameters of the stack can be obtained. This numerical method needs usually initial guess of the kind of results. Fourier transform method allows to obtain directly the values of distances between interfaces, with a good approximation depending on the maximum angular scan of the measure. It can also reveal some particularity of the multilayer, i.e. periodic multilayered structures with more than two layers per period. As an illustration of this characterization method, some examples in XUV optical domain will be shown. This method can also be used for the characterization of many kinds of multilayer stacks, in particular semi-conductor heterostructures ones, under the condition that adjacent layers have sufficient contrast index at the wavelength of the X-ray source.

Bridou, F.; Gautier, J.; Delmotte, F.; Ravet, M.-F.; Durand, O.; Modreanu, M.

2006-10-01

115

Transforming growth factor-alpha: Characterization of the BamHl, Rsal, and Taql polymorphic regions  

SciTech Connect

The authors have characterized the nature of structural alleles of the transforming growth factor-alpha (TGF[alpha]) locus by restriction-enzyme digestion with BamHI, RsaI, and TaqI. The BamHl polymorphic site is located within exon Vi, which codes for the 3' untranslated region. The two BamHI alleles differ by a single point mutation at the restriction site. The RsaI and TaqI polymorphic sites are located within intron V. The two alleles differ at the restriction site, either by a point mutation (RsaI) or by a 4-bp deletion (TaqI). This analysis permits the authors to devise a PCR method coupled with restriction digestions to directly identify the TGF[alpha] polymorphisms. Analysis of 99 Caucasian controls has revealed a highly significant (P < .001) association between the RsaI and the BamHI genotype. The frequency of the rare BamHI allele was significantly higher (P < .001) in transformed cell lines (.30) than in controls (.076). 28 refs., 4 figs., 5 tabs.

Qian, J.F.; May, E. (Institut de Recherches Scientifiques sur le Cancer, Villejuif (France)); Feingold, J. (INSERM Unite, Paris (France)); Stoll, C. (Institut de Puericulture, Strasbourg (France))

1993-07-01

116

Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy.  

PubMed

The magnetomechanical properties of ferromagnetic shape memory alloy Ni-Mn-Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni-Mn-Ga single crystal. Experiments were performed in the martensite phase at 25 degrees C and in the austenite phase at 55 degrees C. Two distinct twinning surface reliefs were observed at room temperature. At elevated temperature (55 degrees C), the surface relief of one twinning mode disappeared while the other relief remained unchanged. When cooled back to 25 degrees C, the twin surface relief recovered. The relief persisting at elevated temperature specifies the positions of twin boundaries that were present when the sample was polished prior to surface characterization. AFM and MFM following thermomechanical treatment provide a nondestructive method to identify the crystallographic orientation of each twin and of each twin boundary plane. Temperature dependent AFM and MFM experiments reveal the twinning history thereby establishing the technique as a unique predictive tool for revealing the path of the martensitic and reverse transformations of magnetic shape memory alloys. PMID:20589105

Reinhold, Matthew; Watson, Chad; Knowlton, William B; Müllner, Peter

2010-06-01

117

Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy  

PubMed Central

The magnetomechanical properties of ferromagnetic shape memory alloy Ni–Mn–Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni–Mn–Ga single crystal. Experiments were performed in the martensite phase at 25 °C and in the austenite phase at 55 °C. Two distinct twinning surface reliefs were observed at room temperature. At elevated temperature (55 °C), the surface relief of one twinning mode disappeared while the other relief remained unchanged. When cooled back to 25 °C, the twin surface relief recovered. The relief persisting at elevated temperature specifies the positions of twin boundaries that were present when the sample was polished prior to surface characterization. AFM and MFM following thermomechanical treatment provide a nondestructive method to identify the crystallographic orientation of each twin and of each twin boundary plane. Temperature dependent AFM and MFM experiments reveal the twinning history thereby establishing the technique as a unique predictive tool for revealing the path of the martensitic and reverse transformations of magnetic shape memory alloys.

Reinhold, Matthew; Watson, Chad; Knowlton, William B.; Mullner, Peter

2010-01-01

118

Infrared absorption and admittance spectroscopy of Ge quantum dots on a strained SiGe layer  

NASA Astrophysics Data System (ADS)

A combined infrared absorption and admittance spectroscopy is carried out in examining the energy level structure and the hole emission process in self-assembled Ge quantum dots (QDs) placed on a strained Si0.65Ge0.35 quantum well (QW), which, in turn, is incorporated in a Si matrix. In the midinfrared spectral range, the dots exhibit three dominant absorption bands peaked at 130, 250 and 390 meV. By a comparison between absorption measurements and six-band {\\bf k}\\;{\\bm \\cdot}\\;{\\bf p} calculations, the long-wave (~130 meV) resonance is attributed to a transition from the QD hole ground state to the two-dimensional heavy-hole states confined in the Si0.65Ge0.35 layer. The mid-wave absorption band around 390 meV is ascribed to a transition from the QD hole ground state to the three-dimensional continuum states of the Si matrix. An equivalent absorption cross section for these two types of transitions is determined to be 1.2 × 10-15 cm2 and 1.2 × 10-16 cm2, respectively. The origin of the transmission minimum around 250 meV is more ambiguous. We tentatively propose that it can be due to transition either from the highest heavy-hole subband of the Si0.65Ge0.35 QW to continuum states above the Si barrier or from the dot states to the light-hole and split-off subbands of the Si0.65Ge0.35 layer. The photoinduced bleaching of the near-infrared absorption is detected under interband optical excitation of undoped samples. This finding is explained by blocking the interband transitions inside the dots due to the state filling effect. By using the admittance spectroscopy, the mechanism of hole escape from QDs in the presence of an ac vertical electric field is identified. A thermally activated emission from the QD ground state into the two-dimensional states of the Si0.65Ge0.35 well is observed. From the temperature- and frequency-dependent measurements the QD hole ground state is determined to be located ~160 meV below the heavy-hole subband of the Si0.65Ge0.35 layer in good agreement with the results obtained by infrared absorption spectroscopy and six-band {\\bf k}\\;{\\bm \\cdot}\\;{\\bf p} theory. The information acquired from our experimental observations is valuable for feasible device applications.

Yakimov, A. I.; Nikiforov, A. I.; Timofeev, V. A.; Dvurechenskii, A. V.

2011-12-01

119

Transformation method for problems involving perfect electromagnetic conductor (PEMC) structures  

Microsoft Academic Search

Perfect electric conductor (PEC) and perfect magnetic conductor (PMC) can be generalized to perfect electromagnetic conductor (PEMC), a medium where certain linear combinations of electromagnetic fields are required to vanish. In differential-form representation, the corresponding medium is characterized as the simplest possible medium. It is defined through a scalar admittance parameter, whose zero and infinite limits yield the PMC and

Ismo V. Lindell; Ari H. Sihvola

2005-01-01

120

Characterization of Barrett esophagus and esophageal adenocarcinoma by Fourier-transform infrared microscopy.  

PubMed

The objective of this exploratory study was to evaluate the feasibility of using Fourier-Transform Infrared (FTIR) spectromicroscopy to characterize formalin-fixed, paraffin-embedded human esophageal tissues. Matched histologically normal esophageal squamous epithelium (NS), premalignant Barrett esophagus (BE), and primary esophageal adenocarcinoma (EADC) tissues, each defined according to strict clinicopathologic criteria, were obtained from patients who underwent esophageal resection. Using confocal IR microscopy, measurements in the mid-IR spectral region were carried out in transflection configuration, scanning regions of interest in 15 microm steps. A multidimensional dataset reporting the spectroscopic properties at each sampled point were analyzed by performing a hierarchical cluster analysis on the second derivative of spectral traces. Normal esophageal epithelia were characterized by a few well defined regions, mostly of large size (tens of contiguous pixels), which correlated with tissue histology, specifically the basal cell layer. BE tissues had characteristic regions localized to gland crypts, ranging in size from one pixel to a few tens of pixels, which displayed IR spectra with defined absorption features characteristic of glycoproteins. The incorporation of synchrotron light to improve the resolution of individual cells in BE tissues has demonstrated that these glycoproteins are associated with goblet cells, the characteristic cell type defining BE. Whereas the highly fragmented regions identified in EADC likely reflect tumor heterogeneity, FTIR mapping would appear to be a potentially useful technique to identify premalignant BE tissues. The technical feasibility of using FTIR to characterize formalin-fixed, paraffin-embedded human esophageal tissues demonstrates the potential of this technique to study archival human BE tissue specimens via automated screening techniques. PMID:19475154

Quaroni, Luca; Casson, Alan G

2009-02-11

121

Computerized characterization of masses on mammograms: the rubber band straightening transform and texture analysis.  

PubMed

A new rubber band straightening transform (RBST) is introduced for characterization of mammographic masses as malignant or benign. The RBST transforms a band of pixels surrounding a segmented mass onto the Cartesian plane (the RBST image). The border of a mammographic mass appears approximately as a horizontal line, and possible speculations resemble vertical lines in the RBST image. In this study, the effectiveness of a set of directional textures extracted from the images before the RBST. A database of 168 mammograms containing biopsy-proven malignant and benign breast masses was digitized at a pixel size of 100 microns x 100 microns. Regions of interest (ROIs) containing the biopsied mass were extracted from each mammogram by an experienced radiologist. A clustering algorithm was employed for automated segmentation of each ROI into a mass object and background tissue. Texture features extracted from spatial gray-level dependence matrices and run-length statistics matrices were evaluated for three different regions and representations: (i) the entire ROI; (ii) a band of pixels surrounding the segmented mass object in the ROI; and (iii) the RBST image. Linear discriminant analysis was used for classification, and receiver operating characteristic (ROC) analysis was used to evaluate the classification accuracy. Using the ROC curves as the performance measure, features extracted from the RBST images were found to be significantly more effective than those extracted from the original images. Features extracted from the RBST images yielded an area (Az) of 0.94 under the ROC curve for classification of mammographic masses as malignant and benign. PMID:9571620

Sahiner, B; Chan, H P; Petrick, N; Helvie, M A; Goodsitt, M M

1998-04-01

122

Thermomechanical modeling of polycrystalline SMAs under cyclic loading, Part II: material characterization and experimental results for a stable transformation cycle  

Microsoft Academic Search

Material characterization of polycrystalline Shape Memory Alloys (SMAs) during a stable phase transformation cycle is presented in this paper using the constitutive model established by Bo and Lagoudas (Z. Bo, D.C. Lagoudas, accepted for publication in International Journal of Engineering Science) in the first paper of this series, to be referenced here as Part I. In addition to the constitutive

Dimitris C. Lagoudas; Zhonghe Bo

1999-01-01

123

Characterization of spectral regrowth in microwave amplifiers based on the nonlinear transformation of a complex Gaussian process  

Microsoft Academic Search

A statistical technique is presented for the characterization of spectral regrowth at the output of a nonlinear amplifier driven by a digitally modulated carrier in a digital radio system. The technique yields an analytical expression for the autocorrelation function of the output signal as a function of the statistics of the quadrature input signal transformed by a behavioral model of

Kevin G. Gard; Hector M. Gutierrez; Michael B. Steer

1999-01-01

124

Parametric study and characterization of the isobaric thermomechanical transformation fatigue of nickel-rich NiTi SMA actuators  

Microsoft Academic Search

The recent development of various aerospace applications utilizing Ni-rich NiTi Shape memory Alloys (SMAs) as actuators motivated the need to characterize the cyclic response and the transformation fatigue behavior of such alloys. The fatigue life validation and certification of new designs is required in order to be implemented and used in future applications. For that purpose, a custom built fatigue

Olivier W. Bertacchini; Justin Schick; Dimitris C. Lagoudas

2009-01-01

125

Treatment of frequency-dependent admittance boundary conditions in transient acoustic finite/infinite-element models.  

PubMed

The paper addresses the handling of frequency-dependent, local admittance boundary conditions in acoustic transient finite/infinite-element models. The proposed approach avoids the evaluation of a convolution integral along the related boundary. Based on a similar technique developed in an aeroacoustic/finite difference context, the spatially local boundary condition is rewritten in a discrete form that involves normal accelerations and pressure time derivatives at the current time step and few steps before. The incorporation of such a discrete (in time) boundary condition in a finite/infinite-element context is addressed. The infinite-element scheme selected for that purpose relies on the conjugated Astley-Leis formulation. Implementation aspects cover the handling of frequency-dependent boundary conditions along both finite- and infinite-element edges. Numerical examples (waveguide, single source in a half-space bounded by an impedance plane, diffraction by an acoustically treated screen) are presented in order to demonstrate the efficiency of the proposed approach. PMID:11681354

Van den Nieuwenhof, B; Coyette, J P

2001-10-01

126

Characterization, design and modeling of on-chip interleaved transformers in CMOS RFICs  

Microsoft Academic Search

This paper discusses the impacts of key geometrical parameters on the performance of interleaved transformers in CMOS radio\\u000a frequency integrated circuits (RFICs). It also presents a compact circuit model for the transformer based on the “2-?” model\\u000a of on-chip spiral inductors. All the RLC circuit elements can be calculated from the transformer’s geometrical and process\\u000a parameters. Verification with accurately calibrated

Dan Zhao; Kiat Seng Yeo; Manh Anh Do; Chirn Chye Boon

2011-01-01

127

Fabrication and characterization of a switchable flux transformer using a DC-SQUID  

Microsoft Academic Search

We have investigated a switchable flux transformer which consists of a superconducting loop and a DC-SQUID. The effective magnetic flux in the DC-SQUID was controlled by a control current, which was injected in the segment of the SQUID loop. The equation describing the behavior of the circulating current in the transformer was derived. We fabricated the flux transformer coupled with

Y. Shimazu; T. Niizeki; Y. Wada

2006-01-01

128

Cloning, expression, and characterization of chicken transforming growth factor beta 4.  

PubMed

Transforming growth factor beta 4 (TGF-beta 4) is unique to avian species, though its roles in vivo have not yet been well established. In this paper we describe the expression and partial characterization of recombinant chicken TGF-beta 4. By using a GC-rich PCR system in a modified 5'RACE methodology we generated the 5'-end of cDNA sequence encoding the TGF-beta 4 precursor, which was in-frame cloned into pcDNA3.1/V5-His-TOPO and transfected into the Chinese hamster ovary cell line (CHO-K1). A cell line stably expressing TGF-beta 4 precursor protein was established from CHO-K1 cells. Acid-activated mature TGF-beta 4 inhibited the growth of mink lung epithelial (Mv1Lu) cell line. TGF-beta 4 also stimulated the expression of type I procollagen and enhanced heat shock protein 47 (Hsp47) expression in chicken tendon fibroblasts. Hsp47 expression by TGF beta 4 is likely regulated through activation of heat shock transcription factor 1 (HSF1). Because the presence of TGF-beta 1 has not been documented in avian cells and our data show that TGF-beta 4 elicits biological activities in chicken tendon cells, which closely parallel that of TGF-beta 1, we propose that TGF-beta 4 plays roles in avian species similar to what TGF-beta 1 plays in mammalian species. PMID:12646161

Pan, Hongjie; Halper, Jaroslava

2003-03-28

129

Chemical characterization of lased root surfaces using Fourier transform infrared photoacoustic spectroscopy.  

PubMed

Recently lasers have been recommended as an alternative or adjunctive therapy in the control and treatment of periodontally diseased root surfaces. The purpose of this in vitro investigation was to characterize the chemical structure of lased root surfaces using Fourier transform infrared photoacoustic spectroscopy (FTIR/PAS). Cementum samples, 6 mm x 2 mm, were cut from the root surface of extracted non-carious, unerupted human molars. The experimental samples were lased with a Nd:YAG laser at an average energy of 80 mJ at 10 pulses per second. Total lasing time ranged from 1 minute 45 seconds to 4 minutes. A non-lased cementum sample served as the control. All spectra were recorded from 4000 to 400 cm-1 using the photoacoustic cell attachment on an Analect RFX-65 FTIR Spectrometer. Photoacoustic FTIR spectra of lased cementum samples showed a decrease in the protein/mineral ratio in comparison to the control. Breakdown of protein at the root surface potentially contributed to an ammonium band at 2010 cm-1. The decreased protein/mineral ratio and the potential surface contamination with protein by-products, may ultimately affect cell reattachment at the cementum surface. PMID:1507041

Spencer, P; Trylovich, D J; Cobb, C M

1992-07-01

130

Characterization of primary human keratinocytes transformed by human papillomavirus type 18  

SciTech Connect

Primary human epithelial cells were cotransfected with pHPV-18 and pSV2neo, and cell strains were generated by selecting in G418. Southern blot analysis revealed the presence of at least one intact, integrated viral genome in these cells. FE-A cells showed altered growth properties, characterized by a change in morphology, and clonal density. Differentiation markers analyzed by Western blotting (immunoblotting), such as cytokeratins and involucrin, indicated that the cells resembled a partially differentiated epithelial population. Increased expression of the 40-kilodalton cytokeratin was observed in FE-A cells, similar to that observed in simian virus 40-immortalized human keratinocytes. Calcium and 12-O-tetradecanoyl-phorbol-13-acetate treatment induced normal epithelial cells to differentiate, whereas the human papillomavirus 18 (HPV-18)-containing keratinocytes were resistant to these signals, indicating their partially transformed nature. These cells were not able to induce tumors in nude mice over a period of up to 8 months. A second cell strain, FE-H18L, also generated by transfecting HPV-18, also exhibited an extended life span and similar alterations in morphology. Viral RNA transcribed from the early region of HPV-18 was detected in both cell strains by Northern (RNA) blot analysis. These cell strains should provide a useful model for determining the role of HPV in carcinogenesis.

Kaur, P.; McDougall, J.K. (Fred Hutchinson Cancer Research Center, Seattle, WA (USA))

1988-06-01

131

Characterization of transforming growth factors beta1 and 2 in ferrets (Mustela putorius furo).  

PubMed

Unwanted scar tissue after surgical procedures remains a central problem in medicine. Nowhere is this problem more evident than within the pediatric airway, where excess scarring, termed subglottic stenosis, can compromise breathing. Recent advances in molecular biology have focused on ways to decrease scar formation through understanding of the wound repair process. Transforming growth factor beta (TFGbeta) plays a central role in this pathway. Ferrets serve as an ideal model for the pediatric airway, and reproduction of subglottic stenosis in ferrets is possible. However, ferret cytokine profiles have not been established. In this study, we characterized the presence and nucleotide sequence of the TGFbeta1 and 2 genes in ferrets by using total RNA isolated from airways. Amino acid sequence homology between human and ferret was determined to be 96.6% for TGFbeta1 and 99.3% for TGFbeta2. Given the nearly total homology between TGFbetas of ferret and human origin, the ferret may serve as an ideal model for future molecular studies. PMID:18246873

Senchak, Andrew J; Sato, Aileen K; Vazquez, Raymond; Keller, Christopher E; Cable, Benjamin B

2007-12-01

132

Novel Thermographic Method for Characterizing Transformation Temperatures of Thin-Film Shape Memory Alloys Aimed at Combinatorial Approach  

NASA Astrophysics Data System (ADS)

A novel characterization method for the two-way martensitic transformation temperatures of thin-film shape memory alloys (SMAs) is proposed. The method uses thermography to detect the transformation as a change in emissivity. The proposed method was demonstrated for a Ti--Pd--Ni thin-film SMA along with electrical resistivity monitoring. Definite emissivity changes were observed during both heating and cooling. Furthermore, the changes in emissivity corresponded to changes in the electrical resistivity. To confirm the validity of the proposed method, the results were compared with results obtained using conventional differential scanning calorimetry (DSC). The reverse-martensitic transformation temperature was found to agree with the results of the proposed method. However, the martensitic transformation temperature did not agree well. The reason for this disagreement is the differences in the definition of the transformation temperature and stress conditions used. We expect that the proposed method will enable high-throughput characterization of SMAs by a combinatorial approach in the future.

Aono, Yuko; Sakurai, Junpei; Shimokohbe, Akira; Hata, Seiichi

2011-06-01

133

An analysis of light-induced admittance changes in rod outer segments  

PubMed Central

1. Measurements were made of the time course and amplitude of the change in real part of admittance, ?G, of a suspension of frog rod outer segments, following a flash of light bleaching about 1% of the rhodopsin content of the rods. The measurements, based on the use of a specially designed marginal oscillator, covered the frequency range between 500 Hz and 17 MHz. 2. The components of response, previously described for rods prepared by a method involving exposure to strongly hypertonic sucrose solutions, are present in similar form when rods are isolated and maintained in isotonic solutions made up with equi-osmotic concentrations of NaCl and sucrose or with Na2SO4. 3. Component I, identified as a slowly developing positive ?G apparent at very low frequencies, is frequency-independent up to the characteristic frequency of admittance for the suspension, fY (about 2 MHz for rods suspended in a solution having the conductivity of Ringer solution), but decreases at still higher frequencies. 4. Component II, identified as a rapidly developing positive ?G which appears only above a critical frequency about 2·5 decades below fY, increases approximately logarithmically with frequency to reach a limiting amplitude in the region of fY. 5. The amplitude of component II, ?GII, measured in the region of fY, varies linearly with the conductivity of the suspending medium, Go, under conditions in which the conductivity of the rod interior is also a linear function of the external conductivity. The relation for a flash bleaching 1% of the rhodopsin content of the dark-adapted rod is [Formula: see text] 6. Measurements made on rods suspended in a low-conductivity solution, which has the effect of reducing the conductivity of the rod interior to about one ninth its value for rods suspended in Ringer solution, reveal a decline in component II for frequencies above 8 MHz. 7. To explain the frequency dependence of component II and its dependence on conductivity, it is proposed that component II arises from a light-induced increase in conductance of the disk membranes which obstruct the longitudinal flow of current through the rod interior except at very high frequencies. 8. The disk-membrane conductance increase for rods suspended in a solution having the conductivity of Ringer solution is calculated to be 4·3 × 10-11 mho/rhodpsin molecule bleached, a value which is similar to what has been found for ionic channels operated by membrane potential change in the nerve membrane and by synaptic transmitter in the postjunctional membrane. 9. No component of response has been observed which could be reliably attributed to a surface membrane conductance decrease of the type observed in receptor cells in the retina.

Falk, G.; Fatt, P.

1973-01-01

134

Isolation and characterization of bacteria degrading polychlorinated biphenyls from transformer oil  

Microsoft Academic Search

Polychlorinated biphenyls from transformer oil were degraded in liquid culture under aerobic conditions using a mixed bacterial\\u000a culture isolated from a transformer oil sample with a high content of polychlorinated biphenyls and other hydrocarbons. Four\\u000a strains were identified, three of them corresponded to genusBacillus, the other one toErwinia. Bacteria in the transformer oil could remove as much as 65% of

N. G. Rojas-Avelizapa; R. Rodríguez-Vázquez; J. Martínez-Cruz; F. Esparza-García; A. Montes de Oca-García; E. Ríos-Leal; G. Fernández-Villagómez

1999-01-01

135

ZnO thin film characterization by X-ray reflectivity optimization using genetic algorithm and Fourier transformation  

NASA Astrophysics Data System (ADS)

Zinc oxide (ZnO) thin film was fabricated by sol-gel spin coating method on glass substrate. X-ray reflectivity (XRR) and its optimization have been used for characterization and extracting physical parameters of the film. Genetic algorithm (GA) has been applied for this optimization process. The model independent information was needed to establish data analyzing process for X-ray reflectivity before optimization process. Independent information was exploited from Fourier transform of Fresnel reflectivity normalized X-ray reflectivity. This Fourier transformation (Auto Correlation Function) yields thickness of each coated layer on substrate. This information is a keynote for constructing optimization process. Specular X-ray reflectivity optimization yields structural parameters such as thickness, roughness of surface and interface and electron density profile of the film. Acceptable agreement exists between results obtained from Fourier transformation and X-ray reflectivity fitting.

Solookinejad, Ghahraman; Rozatian, Amir Sayid Hassan; Habibi, Mohammad Hossein

2011-10-01

136

Characterization of masses on mammograms: significance of using the rubber band straightening transform  

NASA Astrophysics Data System (ADS)

The rubber-band straightening transform (RBST) was developed for characterization of mammographic masses as malignant or benign. The RBST maps a region surrounding a segmented mass on a mammogram onto the Cartesian plane. In this study, the effectiveness of texture features extracted from the RBST images was compared with the effectiveness of those extracted from the original images. Texture features were extracted from (1) a region of interest (ROI) centered at the mass; (2) a 40-pixel-wide gray-scale region surrounding the perimeter of the mass; and (3) the RBST image. Two types of texture features were extracted; spatial gray level dependence (SGLD) features and run-length statistics (RLS) features. Linear discriminant analysis and leave-one-case- out methods were used for classification in the individual or combined feature spaces. The classification accuracy was evaluated by receiver operating characteristic (ROC) analysis and the area Az under the ROC curve. CLABROC analysis was used to estimate the statistical significance of the difference between features extracted using the three different approaches. On a database of 255 ROIs containing biopsy-proven masses, the Az value was 0.92 when combined SGLD and RLS features extracted from RBST images were used for classification. In comparison, the combined texture features extracted from the entire ROIs and the mass perimeter regions resulted in Az values of 0.83 and 0.85, respectively. The improvement in Az obtained by using RBST images was statistically significant (p less than 0.05). Similar levels of significance were observed when the classification was performed in the SGLD feature space alone or the RLS feature space alone.

Sahiner, Berkman; Chan, Heang-Ping; Petrick, Nicholas; Goodsitt, Mitchell M.; Helvie, Mark A.

1997-04-01

137

Stream flow characterization and feature detection using a discrete wavelet transform  

Microsoft Academic Search

An exploration of the wavelet transform as applied to daily river discharge records demonstrates its strong potential for quantifying stream flow variability. Both periodic and non-periodic features are detected equally, and their locations in time preserved. Wavelet scalograms often reveal structures that are obscure in raw discharge data. Integration of transform magnitude vectors over time yields wavelet spectra that reflect

Laurence C. Smith; Donald L. Turcotte; Bryan L. Isacks

1998-01-01

138

Agronomic performance and genetic characterization of sugarcane transformed for resistance to sugarcane yellow leaf virus  

Microsoft Academic Search

Sugarcane yellow leaf virus (SCYLV, a Poleovirus of the Luteoviridae family) is already widespread in Florida, and resistance in the Canal Point (CP) sugarcane population is limited. Genetic transformation of sugarcane for disease resistance holds promise but tissue culture and transformation processes produce undesirable agronomic characteristics necessitating thorough field evaluation. A 3-year sugarcane (a complex hybrid of Saccharum species) field

R. A. Gilbert; N. C. Glynn; J. C. Comstock; M. J. Davis

2009-01-01

139

Causes of death after surgery for colon cancer-impact of other diseases, urgent admittance, and gender.  

PubMed

Abstract Objective. In patients with colon cancer, high age and comorbidity is common. In this population-based retrospective study we have investigated causes of death and the influence of urgent operation, and gender on survival. Material and methods. Medical records of 413 patients with verified colon cancer were reviewed. The diagnosis was made during 2000-2006 and operation was performed in 385 patients (93%). Results. The overall 5-year survival after surgery was 48.3%. At the end of the follow-up, 128 patients (54.9%) had verified colon cancer when they died but 105 patients (45.1%) had no signs of colon cancer. Their 5-year survival was 5.5% and 41.9%, respectively (p < 0.0001). Median survival time was significantly shorter after urgent compared with elective admittance, 20.7 months versus 77.9 months, and the 5-year survival 32.4% versus 57.9% (p = 0.0001). The tumor stage at operation was more favorable in patients dying with no signs of colon cancer than in those dying with cancer regarding stage I-II (66.7% versus 16.4%), and stage IV (1.0% versus 53.1%), but not regarding stage III (30.5% versus 29.7%). The overall survival in women who were operated was longer than in men (p = 0.045) as well as survival after elective admittance (p = 0.013). Conclusion. After a median follow-up of 56.1 months almost half of the patients who were dead had died from other causes than colon cancer. Ten percent of those patients had an incorrectly reported diagnosis of colon cancer as cause of death. Urgent admittance was associated with reduced survival time. The median survival time was longer in women than in men. PMID:23964717

Sjödahl, Rune; Rosell, Johan; Starkhammar, Hans

2013-08-22

140

Isolation and characterization of three fungi with the potential of transforming glycyrrhizin.  

PubMed

Three fungi with different types of transformation of glycyrrhizin (GL) were isolated from the soil samples of glycyrrhiza glabra planting area in China. According to their morphologies and 18 S rDNA gene sequence analysis, the three fungi were identified and named as Penicillium purpurogenum Li-3, Aspergillus terreus Li-20 and Aspergillus ustus Li-62. Transforming products analysis by TLC and HPLC-MS indicated that P. purpurogenum Li-3, A. terreus Li-20 and A. ustus Li-62 could stably transform GL into GAMG, GAMG and GA, and GA, respectively. P. purpurogenum Li-3 was especially valuable to directly prepare GAMG for applications in the pharmaceutical industry. PMID:23247917

Wang, Chao; Guo, Xiao-Xiao; Wang, Xiao-Yan; Qi, Feng; Feng, Shi-Jiang; Li, Chun; Zhou, Xiao-Hong

2012-12-18

141

Applications of Fourier Transform Infrared Photoacoustic Spectroscopy to Solid Propellant Characterization.  

National Technical Information Service (NTIS)

Fourier transform infrared photoacoustic spectroscopy (FT-IR-PAS) has been used to examine surfaces of composite solid propellants. Depletion of crystalline energetic material from extruded surfaces and of plasticizer from aged surfaces has been documente...

R. A. Fifer R. A. Pesce-Rodriguez

1991-01-01

142

Transformation from layered to tunnel structures: Synthesis, characterization, and applications of manganese oxide octahedral molecular sieves  

NASA Astrophysics Data System (ADS)

Manganese oxide based octahedral molecular sieves (OMS) have been found to have a wide variety of applications as catalysts, absorbents, and battery materials due to their unique structures and physical and chemical properties. OMS materials are made up of manganese oxide octahedral building blocks sharing comers and edges to form tunnel structures. Manganese species in the framework of OMS materials are mixed valent with various ion-exchangeable cations residing in the tunnels playing important roles in charge balancing and special chemical activities. With different synthetic parameters such as the template used, temperature, pressure, and the pH of the synthetic media, layered birnessite materials were hydrothermally transformed into distinct tunnel structures with different tunnel sizes, including Mg-3x3 (OMS-1), NH4-2x2 (NH4-OMS-2), Na-2x4 (OMS-5), and other manganese oxides. Characterization of the OMS materials with a wide variety of instruments has revealed that most of them are nano-fibrous hollow crystals ith large surface areas, high ion-exchange capabilities, and relatively high thermal stabilities. The Na-2x4 tunnel structure sodium MnOx has been synthesized for the first time and studied in detail, including synthetic strategies, structural analyses, and other physical and chemical property analyses. As catalysts, the synthetic OMS materials show high catalytic activities and shape-selective properties. For example, the results of the competitive oxidation of cycloalkanes with tertiary butyl hydrogen peroxide (TBHP) over different tunnel sized ONIS materials have proven that the OMS materials with larger tunnels are more favorable for the oxidation of the biggest molecule, cyclooctane, than the smallest one, cyclohexane. Besides the tunnel size effects, tunnel cations in the OMS materials also have influences on their catalytic activities. The study of carbon monoxide cleanup for fuel cell applications demonstrates that Ag-OMS-2 (a hollandite structured OMS catalyst with Ag cations residing in the tunnels) is the best oxidative catalyst among many other catalysts. The amount of Ag loading and the average oxidation state of Mn in a Ag-OMS-2 catalyst are the major influences on their catalytic performance. A suitable working temperature range for complete removal of CO from hydrogen-rich reformates using a Ag-OMS-2 catalyst may be adjusted by changing the Ag loading.

Xia, Guan-Guang

143

Characterization of the transformation from calcium-deficient apatite to ?-tricalcium phosphate  

Microsoft Academic Search

The structural changes that occur during the transformation of a Ca-deficient apatite, prepared by a wet chemical method, to ß-TCP were investigated. X-ray diffraction (XRD) analysis of as-prepared samples and samples calcined at temperatures between 500 and 1100 °C showed that the transformation occurs over the temperature range 710–740 °C, under non-equilibrium conditions. The change in crystallite size with increasing

I. R. Gibson; I. Rehman; S. M. Best

2000-01-01

144

Force Control and Nonlinear Master-Slave Force Profile to Manage an Admittance Type Multi-Fingered Haptic User Interface  

SciTech Connect

Natural movements and force feedback are important elements in using teleoperated equipment if complex and speedy manipulation tasks are to be accomplished in remote and/or hazardous environments, such as hot cells, glove boxes, decommissioning, explosives disarmament, and space to name a few. In order to achieve this end the research presented in this paper has developed an admittance type exoskeleton like multi-fingered haptic hand user interface that secures the user’s palm and provides 3-dimensional force feedback to the user’s fingertips. Atypical to conventional haptic hand user interfaces that limit themselves to integrating the human hand’s characteristics just into the system’s mechanical design this system also perpetuates that inspiration into the designed user interface’s controller. This is achieved by manifesting the property differences of manipulation and grasping activities as they pertain to the human hand into a nonlinear master-slave force relationship. The results presented in this paper show that the admittance-type system has sufficient bandwidth that it appears nearly transparent to the user when the user is in free motion and when the system is subjected to a manipulation task, increased performance is achieved using the nonlinear force relationship compared to the traditional linear scaling techniques implemented in the vast majority of systems.

Anthony L. Crawford

2012-08-01

145

[Predictors of unawareness of HIV serostatus among women submitted to the rapid HIV test at admittance for delivery].  

PubMed

This article aims to analyze factors associated with unawareness of prenatal HIV serostatus at admittance for delivery. A cross-sectional study was performed in 2006 in "Friends of Children" Hospitals from the High-risk Pregnancy System, belonging to the Unified Health System, in Rio de Janeiro City. Data were collected through interviews applied to 873 rooming-in mothers submitted to a rapid HIV test at the hospital. Prevalence ratios (PR) of the lack of HIV serologic status were estimated by Poisson regression with robust variance, controlled by maternal and familiar socio-demographic characteristics, pregnancy and prenatal care. Prevalence of unawareness of HIV status was 32.2%. Mothers with low educational level, low-income, more than one relationship in the last year, enrolling late in prenatal care, and low number of prenatal visits were more likely to have unknown HIV status. The main predictor for unawareness of HIV serostatus at hospital admittance was the low number of prenatal visits. It is recommended that coverage of HIV testing during prenatal care be broadened with timely delivery of results, improving early access of pregnant women and increasing the number of prenatal visits, focusing on clients with low socio-economic level. PMID:23670459

Soares, Marcelo de Lima; de Oliveira, Maria Inês Couto; Fonseca, Vânia Matos; Brito, Alexandre dos Santos; da Silva, Kátia Silveira

2013-05-01

146

In situ characterization of phase transformations in a magnetic field in Fe-Ni alloys  

NASA Astrophysics Data System (ADS)

We have investigated the effect of magnetic field on the austenite(?)-ferrite(?) equilibrium in Fe-xNi alloys with x = 0, 2, 4 wt%. The ??? and ??? transformations have been followed as a function of applied magnetic field by a laser dilatometer installed in a 16T superconducting magnet. In addition, magnetic measurements at high temperature have been used to follow the magnetic behavior of each alloy composition during a complete heat treatment. We observe a shift of the phase diagram to higher temperature as the magnetic field is increased. We also find that the ?-phase is either in the paramagnetic or in the ferromagnetic state as the transformation proceeds, depending on the amount of Ni. This results in an increase of the transformation temperature which is respectively proportional to the magnetic field if ferrite is formed in the ferromagnetic state and proportional to the square of the magnetic field if ferrite is paramagnetic.

Garcin, T.; Rivoirard, S.; Beaugnon, E.

2009-03-01

147

Characterization of phase transformation in shape memory alloys by atomic force microscope  

NASA Astrophysics Data System (ADS)

An atomic force microscope operated at various temperatures is introduced to evaluate phase transformation temperature and to observe microstructure for a shape memory alloy at same time in this paper. A commercial hot-rolled TiNi shape memory alloy bar is ground, polished and etched. The specimen is then observed by atomic force microscopy at the temperature range of 20 100 ?C in nitrogen gas. The topographies of a TiNi specimen show twinning martensite with rough surface and smooth austenite at various temperatures. The shape memory effect of the TiNi alloy is analyzed based on the shifts of the topographies obtained at various temperatures, which are used to evaluate the phase transformation temperature between martensite and austenite. The phase transformation temperature is also confirmed in a differential scanning calorimeter (DSC) experiment.

Xu, S. S.; Xu, C. H.; Woo, C. H.; Surya, C.

2008-08-01

148

Pseudolymphomas of the stomach: a lesion characterized by progressively transformed germinal centres.  

PubMed

Pseudolymphomas of the stomach are frequently associated with chronic peptic ulcer. Out of the 11 cases studied, there were characteristic pathohistological signs of chronic ulceration in eight and suspicion of chronic ulcer in three. Thus it seems that pseudolymphomas frequently represent an exaggerated lymphocytic reaction to chronic ulcer. The pseudolymphomatous reaction is essentially a follicular hyperplasia with the gradual development of progressively transformed germinal centres. These large nodular structures are usually found in the submucosa and, at first inspection, the transformed follicle can easily be mistaken for a possibly malignant diffuse lymphomatous lesion. However, once the existence of the condition is realized, its recognition by the pathologist should be easy. A heavy plasma cell infiltration of polytypic immunoglobulin type associated with progressively transformed germinal centres might be a consequence of long-standing antigenic stimulation. PMID:7056512

Hyjek, E; Kelényi, G

1982-01-01

149

In situ characterizations of phase transformations kinetics in the Ti17 titanium alloy by electrical resistivity and high temperature synchrotron X-ray diffraction  

Microsoft Academic Search

The ?(BCC)??(HCP)+?(BCC) phase transformation kinetics of the ?-metastable titanium alloy Ti17 was studied by in situ high energy X-ray diffraction (XRD) and electrical resistivity. The use of synchrotron radiation (E=89.12?keV, ?=0.01402?nm) allowed to characterize specimens 6?mm in diameter, limiting thus oxidation effects. The ?+??? phase transformation kinetics was characterized during continuous heating up to the ? temperature range. The ???+?

Fabien Bruneseaux; Elisabeth Aeby-Gautier; Guillaume Geandier; Julien Da Costa Teixeira; Benoît Appolaire; Patrick Weisbecker; Anthony Mauro

2008-01-01

150

Hydrocarbon characterization by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry  

SciTech Connect

The ultrahigh-resolution capabilities of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) have been demonstrated for accurate mass measurements of complex hydrocarbon mixtures. Ultrahigh resolution is achievable over a wide mass range by the use of stored waveform inverse Fourier transform (SWIFT) ejection to eliminate space-charge effects. The mass measurement stability under different ionization conditions eliminates the need of mass reference standards during acquisition of sample spectra, thereby increasing sensitivity of the accurate mass measurements under low-voltage electron ionization conditions. 27 refs., 4 figs., 2 tabs.

Hsu, C.S. (Exxon Research and Engineering Company, Annandale, NJ (United States)); Liang, Z. (Exxon Research and Engineering Company, Annandale, NJ (United States) Millipore Corporation, Madison, WI (United States)); Campana, J.E. (Millipore Corporation, Madison, WI (United States))

1994-03-15

151

Establishment and characterization of hamster cell lines transformed by restriction endonuclease fragments of adenovirus 5.  

PubMed Central

We have established a library of hamster cells transformed by adenovirus 5 DNA fragments comprising all (XhoI-C, 0 to 16 map units) or only a part (HindIII-G, 0 to 7.8 map units) of early region 1 (E1: 0 to 11.2 map units). These lines have been analyzed in terms of content of viral DNA, expression of E1 antigens, and capacity to induce tumors in hamsters. All cells tested were found to express up to eight proteins encoded within E1A (0 to 4.5 map units) with apparent molecular weights between 52,000 (52K) and 25K. Both G and C fragment-transformed lines expressed a 19K antigen encoded within E1B (4.5 to 11.2 map units), whereas an E1B 58K protein was detected in C fragment-transformed, but not G-fragment-transformed, lines. No clear distinction could be drawn between cells transformed by HindIII-G and by XhoI-C in terms of morphology or tumorigenicity, suggesting that the E1B 58K antigen plays no major role in the maintenance of oncogenic transformation, although possible involvement of truncated forms of 58K cannot be ruled out. Sera were collected from tumor-bearing animals and examined for ability to immunoprecipitate proteins from infected cells. The relative avidity of sera for different proteins was characteristic of the cell line used for tumor induction, and the specificity generally reflected the array of viral proteins expressed by the corresponding transformed cells. However, one notable observation was that even though all transformed lines examined expressed antigens encoded by both the 1.1- and 0.9-kilobase mRNAs transcribed from E1A, tumor sera made against these lines only precipitated products of the 1.1-kilobase message. Thus, two families of E1A proteins, highly related in terms of primary amino acid sequence, appear to be immunologically quite distinct. Images

Rowe, D T; Branton, P E; Yee, S P; Bacchetti, S; Graham, F L

1984-01-01

152

Characterization of pyrogenic black carbon by desorption atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

We present a new method for molecular characterization of intact biochar directly, without sample preparation or pretreatment, on the basis of desorption atmospheric pressure photoionization (DAPPI) coupled to Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Conventional ionization methods (e.g., electrospray or atmospheric pressure photoionization) for characterization of natural organic matter have limited utility for the characterization of chars due to incomplete solubility in common solvents. Therefore, direct ionization techniques that do not require sample dissolution prior to analysis are ideal. Here, we apply DAPPI FTICR mass spectrometry to enable the first molecular characterization of uncharred parent oak biomass and after combustion (250 °C) or pyrolysis (400 °C). Parent oak is primarily composed of cellulose-, lignin-, and resin-like compounds. Oak combusted at 250 °C contains condensed aromatic compounds with low H/C and O/C ratios while retaining compounds with high H/C and O/C ratios. The bimodal distribution of aromatic and aliphatic compounds observed in the combusted oak sample is attributed to incomplete thermal degradation of lignin and hemicellulose. Pyrolyzed oak constituents exhibit lower H/C and O/C ratios: approximately three-quarters of the identified species are aromatic. DAPPI FTICR MS results agree with bulk elemental composition as well as functional group distributions determined by elemental analysis and solid state (13)C NMR spectroscopy. Complete molecular characterization of biomass upon thermal transformation may provide insight into the biogeochemical cycles of biochar and future renewable energy sources, particularly for samples currently limited by solubility, separation, and sample preparation. PMID:22242739

Podgorski, David C; Hamdan, Rasha; McKenna, Amy M; Nyadong, Leonard; Rodgers, Ryan P; Marshall, Alan G; Cooper, William T

2012-01-18

153

Characterization of cancer and normal tissue fluorescence through wavelet transform and singular value decomposition  

Microsoft Academic Search

The statistical and characteristic features of the polarized fluorescence spectra from cancer, normal and benign human breast tissues are studied through wavelet transform and singular value decomposition. The discrete wavelets enabled one to isolate high and low frequency spectral fluctuations, which revealed substantial randomization in the cancerous tissues, not present in the normal cases. In particular, the fluctuations fitted well

Anita H. Gharekhan; Nrusingh C. Biswal; Sharad Gupta; Asima Pradhan; M. B. Sureshkumar; Prasanta K. Panigrahi

2008-01-01

154

Using wavelet transforms for ECG characterization. An on-line digital signal processing system  

Microsoft Academic Search

The rapid and objective measurement of timing intervals of the electrocardiogram (ECG) by automated systems is superior to the subjective assessment of ECG morphology. The timing interval measurements are usually made from the onset to the termination of any component of the EGG, after accurate detection of the QRS complex. This article describes a real-time system that uses wavelet transforms

J. S. Sahambi; S. N. Tandon; R. K. P. Bhatt

1997-01-01

155

Cytological characterization of four meiotic mutants of Arabidopsis isolated from T-DNA-transformed lines  

Microsoft Academic Search

A secondary screen of the Feldmann collection of T-DNA transformed Arabidopsis lines identified several meiotic mutants. We used a spreading technique combined with DAPI staining in a detailed cytogenetic analysis of meiotic chromosome behaviour in four of these mutants, all of which are putatively T-DNA tagged and therefore candidates for molecular and functional analysis of the mutated genes. Two of

K. J. Ross; P. Fransz; S. J. Armstrong; I. Vizir; B. Mulligan; F. C. H. Franklin; G. H. Jones

1997-01-01

156

Characterization of grapefruit plants ( Citrus paradisi Macf.) transformed with citrus tristeza closterovirus genes  

Microsoft Academic Search

Grapefruit (Citrus paradisi Macf. cv Duncan) plants were transformed with several sequences from citrus tristeza closterovirus (CTV) that varied in terms of position in the CTV genome and virus strain origin in an attempt to obtain resistant plants. The sequences included the capsid protein gene from three different strains, a nontranslatable version of the capsid protein gene, the replicase (RdRp),

V. J. Febres; C. L. Niblett; R. F. Lee; G. A. Moore

2003-01-01

157

Terahertz Fourier transform characterization of biological materials in a liquid phase  

Microsoft Academic Search

Significant progress has been achieved during the last several years relating to experimental and theoretical aspects of terahertz (or submillimetre wave) Fourier transform spectroscopy of biological macromolecules. However, previous research in this spectral range has been focused on bio-materials in solid state since it was common opinion that high water absorption will obscure the spectral signatures of the bio-molecules in

Tatiana Globus; Dwight Woolard; Thomas W. Crowe; Tatyana Khromova; Boris Gelmont; Jeffrey Hesler

2006-01-01

158

Homologous transformation of the edible basidiomycete Agrocybe aegerita with the URA1 gene: characterization of integrative events and of rearranged free plasmids in transformants  

Microsoft Academic Search

The URA1 gene, encoding dihydroorotate dehydrogenase of the pyrimidine pathway, cloned into pUC18 (pUra1-1) was used to develop an homologous transformation system for the cultivated mushroom Agrocybe aegerita. Protoplasts of a ura1 auxotrophic strain were transformed by electroporation with efficiencies ranging from 1 to 26 transformants per µg of DNA. The phenotype of the stable Ura+transformants suggested a strong nuclear

Thierry Noël; Jacques Labarère

1994-01-01

159

Characterization and transformation of unstructured control flow in bulk synchronous GPU applications  

Microsoft Academic Search

In this paper we identify important classes of program control flows in applications targeted to commercially available graphics processing units (GPUs) and characterize their presence in real workloads such as those that occur in CUDA and OpenCL. Broadly, control flow can be characterized as structured or unstructured. It is shown that most existing techniques for handling divergent control in bulk

Haicheng Wu; Gregory Diamos; Jin Wang; Si Li; Sudhakar Yalamanchili

2012-01-01

160

Phase transformation modeling to characterize carbon diffusivity in steel in the presence of Cr  

SciTech Connect

In a previous publication, a type of macro-microscopic approach is used to develop a numerical model to simulate austenite-pearlite transformation in Fe-C eutectoid steel. The primary aim was to gain some understanding about the mechanisms of pearlite growth suggested in the literature. This was achieved by modeling the eutectoid reaction kinetics based on some simple assumptions. The theories of pearlite growth are well established and to a certain extent, efforts have been made to understand the effect of alloying elements on pearlite transformation. In the present work, an attempt has been made to study the effect of Cr quantitatively on carbon diffusion in order to estimate the diffusion coefficient leading to the pearlite growth.

Munirajulu, M.; Dhindaw, B.K. [I.I.T. Kharagpur (India). Dept. of Metallurgical and Materials Engineering; Biswas, A. [Usha Scientific Research Inst., Tatisilwai (India)

1997-12-01

161

Bio-telemetric device for measurement of left ventricular pressure-volume loops using the admittance technique in conscious, ambulatory rats  

PubMed Central

This paper presents the design, construction and testing of a device to measure pressure volume loops in the left ventricle of conscious, ambulatory rats. Pressure is measured with a standard sensor, but volume is derived from data collected from a tetrapolar electrode catheter using a novel admittance technique. There are two main advantages of the admittance technique to measure volume. First, the contribution from the adjacent muscle can be instantaneously removed. Second, the admittance technique incorporates the nonlinear relationship between the electric field generated by the catheter and the blood volume. A low power instrument weighing 27 g was designed, which takes pressure-volume loops every 2 minutes and runs for 24 hours. Pressure-volume data are transmitted wirelessly to a base station. The device was first validated in thirteen rats with an acute preparation with 2-D echocardiography used to measure true volume. From an accuracy standpoint, the admittance technique is superior to both the conductance technique calibrated with hypertonic saline injections, and calibrated with cuvettes. The device was then tested in six rats with a 24-hour chronic preparation. Stability of the animal preparation and careful calibration are important factors affecting the success of the device.

Raghavan, Karthik; Feldman, Marc D; Porterfield, John E; Larson, Erik R; Jenkins, J Travis; Escobedo, Daniel; Pearce, John A

2011-01-01

162

Characterization of an RNA bulge structure by Fourier transform infrared spectroscopy  

Microsoft Academic Search

There may be several advantages associated with an antisense oligonucleotide that induces a bulged structure into its RNA target molecule. Many structures of RNA bulges are elucidated from single-stranded RNA models. However, a two-component system is the minimum requirement for a realistic antisense model. We have used Fourier transform infrared spectroscopy to investigate a single-stranded RNA oligonucleotide with known NMR

Martina Banyay; Jessica Sandbrink; Roger Strömberg; Astrid Gräslund

2004-01-01

163

Ideutilication and Characterization of Human ß2-Chimaerin: Association with Malignant Transformation in Astrocytoma1  

Microsoft Academic Search

Molecular processes resulting in the malignant transformation from low- to high-grade astrocytoma remain poorly understood. Using reverse transcriptase PCR, we identified a gene that is differentially expressed in normal brain and low-grade astrocytoma compared to glioblastoma tis sues. This gene is identical to human ß2-chimaerin, which encodes a 468-amino acid GTPase-activating protein for pllrac. The gene was localized to human

Shixing Yuan; David W. Miller; Gene H. Barnett; Joseph F. Hahn; Bryan R. G. Williams

1995-01-01

164

Horticultural characterization of Angelonia salicariifolia plants transformed with wild-type strains of Agrobacterium rhizogenes  

Microsoft Academic Search

Genetic transformation was carried out with wild-type strains of Agrobacterium rhizogenes for introducing a dwarf trait into the Scrophulariaceous ornamental plant, angelonia ( Angelonia salicariifolia). Leaf segments of two angelonia genotypes (Ang.1 and Ang.2) were co-cultivated with mikimopine-type strains of A. rhizogenes. Adventitious roots that showed vigorous growth and increased lateral branching when cultured on half-strength Murashige and Skoog's (MS)

Y. Koike; Y. Hoshino; M. Mii; M. Nakano

2003-01-01

165

Establishment and characterization of hamster cell line transformed by restriction endonuclease fragments of Adenovirus 5  

SciTech Connect

The authors have established a library of hamster cells transformed by adenvirus 5 DNA fragments comprising all or only a part of early region 1. These lines have been analyzed in terms of content of viral DNA, expression of E1 antigens, and capacity to induce tumors in hamsters. All cells tested were found to express up to eight proteins encoded within E1A (0 to 4.5 map units) with apparent molecular weights between 52,000 (52K) and 25K. No clear distinction could be drawn between cells transformed by HindIII-G and by Xhol-I-C in terms of morphology or tumorigenicity, suggesting that the E1B 58K antigen plays no major role in the maintenance of oncogenic transformation, although possible involvement of truncated forms of 58K cannot be ruled out. Sera were collected from tumor-bearing animals and examined for ability to immunoprecipitate proteins from infected cells. The relative avidity of sera for different proteins was characteristic of the cell line used for tumor induction, and the specificity generally reflected the array of viral proteins expressed by the corresponding transformed cells. However, one notable observation was that even though examined expressed antigens enoded by both the 1.1- and 0.9-kilobase mRNAs transcribed from E1A, tumor sera made against these lines only precipitated products of the 1.1-kilobase message. Thus, two families of E1A proteins, highly related in terms of primary amino acid sequence, appear to be immunologically quite distinct.

Rowe, D.T.; Branton, P.E.; Yee, S.P.; Bacchetti, S.; Graham, F.L.

1984-01-01

166

Open-path Fourier transform infrared spectrometry characterization of low temperature combustion gases in biomass fuels  

Microsoft Academic Search

Accurate determination of gas concentration emitted during thermal degradation (pyrolysis) of biomass in forest fires is one of the keypoints in recent research on physical-based fire spread models. However, it is a very cumbersome task not well solved by classical invasive sensors and procedures. In this work, a methodology to use open-path Fourier transform-based infrared (OP-FTIR) spectrometry has been applied

A. J. de Castro; A. M. Lerma; F. López; M. Guijarro; C. Díez; C. Hernando; J. Madrigal

2007-01-01

167

Water sorption induced transformations in crystalline solid surfaces: characterization by atomic force microscopy.  

PubMed

The effect of water sorption on the mobility of molecules on the surface of a crystalline anhydrous solid was investigated to understand the mechanism of its transformation to the corresponding hydrate. Theophylline was chosen as the model compound. The transition water activity for anhydrate to hydrate transformation, RH(T), and the deliquescence RH, RH(0), was determined to be 62% and 99%, respectively (25 degrees C). Atomic force microscopy (AFM) was used to study the surface changes of theophylline above and below the transition water activity. Contact-mode AFM showed that the jump-to-contact distance increased appreciably above RH(T), suggesting formation of solution on the surface. At RH(T) < RH < RH(0), using dynamic (AC/"tapping" mode) AFM, the movements of surface steps were visualized. These results from AFM indicated that, below RH(0), the formation of a thin solution film significantly increased surface mobility. Furthermore, when the anhydrate crystal surface was seeded with the hydrate, the propagation of a new hydrate phase was observed by polarized light microscopy. In conclusion, atomic force microscopy provided direct evidence that the phase transformation of anhydrous theophylline to theophylline monohydrate in the solid-state is mediated by a surface solution as a result of water adsorption. PMID:20574999

Chen, Dabing; Haugstad, Greg; Li, Zheng Jane; Suryanarayanan, Raj

2010-09-01

168

The role of cesium carbonate on the electron injection and transport enhancement in organic layer by admittance spectroscopy  

NASA Astrophysics Data System (ADS)

The effect of cesium carbonate (Cs2CO3) doping on the electron transport properties of 4,7-diphenyl-1, 10-phenanthroline (BPhen) layer has been investigated in organic light-emitting diodes (OLEDs). Temperature-dependent admittance spectroscopy studies show that the incorporation of Cs2CO3 from 0 to 42 wt. % can decrease the activation energy of the BPhen layer from 1.3 to 0.18 eV, resulting in the enhanced electron injection and transport with respect to reduced injection barrier and increased conductivity of the BPhen layer. This is consistent with the performance improvement in OLEDs, which yields better electrical characteristics and enhanced luminance efficiency.

Zhao, Jin; Cai, Yong; Yang, Jin-Peng; Wei, Huai-Xin; Deng, Yan-Hong; Li, Yan-Qing; Lee, Shuit-Tong; Tang, Jian-Xin

2012-11-01

169

Isolation and characterization of mutants as an approach to a transformation system in Kluyveromyces marxianus.  

PubMed

A method to obtain K. marxianus mutants has been developed. Different auxotrophic mutants were isolated by nystatin and snail-enzyme enrichment procedures using an incubation time of 2 h before adding the antibiotic or the enzyme respectively. All his mutants analyzed by complementation tests turned out to belong to the same complementation group. Some of them were transformed and complemented by the S. cerevisiae HIS3 gene. These non-reverting his3 mutants contain no heterologous sequence, which is essential to make them acceptable for application in the food industry. PMID:8662215

Basabe, L; Cabrera, N; Yong, V; Menéndez, J; Delgado, J M; Rodríguez, L

1996-06-01

170

Processing and characterization of transformation-toughened ceramics with strength retention to elevated temperatures. Final report  

SciTech Connect

Monolithic and three-layered Al{sub 2}O{sub 3} -- 15 vol % ZrO{sub 2} composites were fabricated by slip casting aqueous slurries. The outer and inner layers of three-layer composites contained unstabilized and partially stabilized ZrO{sub 2}, respectively. Transformation of part of the unstabilized ZrO{sub 2} led to surface compressive stresses in the outer layers. Strain gage, x-ray, indentation crack length, and strength measurements were used to determine the magnitude of residual stresses in the composites. The strength of the three-layer composites ({approx}1200 MPa) was 500--700 MPa higher than that of the monolithic outer layer composites at room temperature and 350 MPa higher at 750{degree}C. The strength differential decreased rapidly above the m {yields} t transformation temperature. Three-layered composites showed excellent damage resistance and improved reliability. Cam follower rollers were fabricated to demonstrate the applicability of this technique for making automotive components.

Cutler, R.A.; Brinkpeter, C.B. [Ceramatec, Inc., Salt Lake City, UT (United States); Vircar, A.V.; Shetty, D.K. [Univ. of Utah (United States)

1994-09-01

171

Characterization of Staphylococcus aureus plasmids introduced by transformation into Bacillus subtilis.  

PubMed Central

Covalently closed circular DNA from five Staphylococcus aureus plasmids has been introduced into Bacillus subtilis. Four of these plasmids (pUB110, pCM194, pSA2100, and pSA0501) have been selected for further study. These plasmids replicate as multicopy autonomous replicons in both Rec+ and Rec- B. subtilis strains. They may be transduced between B. subtilis strains or transformed at a frequency of 10(4) to 10(5) transformants per microgram of DNA. The molecular weights of these plasmids were estimated, and restriction endonuclease cleavage site maps are presented. Evidence is given that pSA2100, an in vivo recombinant of pSA0501 and pCM194 (S. Iord?nescu, J. Bacteriol. 124:597-601, 1975), arose by a fusion of the latter plasmids, possibly by insertion of one element into another as a translocatable element. Genetic information from three other S. aureus plasmids (pK545, pSH2, and pUB101) has also been introduced into B. subtilis, although no covalently closed circular plasmid DNA was recovered. Images

Gryczan, T J; Contente, S; Dubnau, D

1978-01-01

172

Matrix Representation of Three-Phase N-Winding Transformers for Steady-State and Transient Studies  

Microsoft Academic Search

Detailed transformer representations are needed in the analysis of electromagnetic transients and in the analysis of unbalanced steady-state conditions. This paper describes the derivation of mdels for three- phase and single-phase N-winding transformers in the form of branch impedance or admittance matrices, which can be calculated from available test data of positive and zero sequence short-circuit and excitation tests. The

V. Brandwajn; H. W. Donnel; I. I. Dommel

1982-01-01

173

Fourier Transform Infrared Characterization of Moisture Absorption in SiOF Films  

Microsoft Academic Search

In this paper, the water absorption characteristics of as-deposited and annealed liquid-phase-deposited fluorinated silicon oxide (LPD-SiOF) films were investigated to clarify the film properties. The stability of moisture absorption was characterized under an air-exposure environment of 23°C and 65% humidity. The as-deposited LPD-SiOF film was found to easily absorb moisture from air and therefore to become unstable in terms of

Wai-Jyh Chang; Mau-Phon Houng; Yeong-Her Wang

1999-01-01

174

Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy  

Microsoft Academic Search

The magnetomechanical properties of ferromagnetic shape memory alloy Ni-Mn-Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni-Mn-Ga single crystal. Experiments were performed in the martensite phase at 25 °C

Matthew Reinhold; Chad Watson; William B. Knowlton; Peter Müllner

2010-01-01

175

Transformation twinning of Ni–Mn–Ga characterized with temperature-controlled atomic force microscopy  

Microsoft Academic Search

The magnetomechanical properties of ferromagnetic shape memory alloy Ni–Mn–Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni–Mn–Ga single crystal. Experiments were performed in the martensite phase at 25 °C

Matthew Reinhold; Chad Watson; William B. Knowlton

2010-01-01

176

Radial current high power dummy load for characterizing the high power laser triggered transformer-type accelerator  

NASA Astrophysics Data System (ADS)

A radial-current aqueous resistive solution load was applied to characterize a laser triggered transformer-type accelerator. The current direction in the dummy load is radial and is different from the traditional load in the axial. Therefore, this type of dummy load has smaller inductance and fast response characteristic. The load was designed to accommodate both the resistance requirement of accelerator and to allow optical access for the laser. Theoretical and numerical calculations of the load's inductance and capacitance are given. The equivalent circuit of the dummy load is calculated in theory and analyzed with a PSPICE code. The simulation results agree well with the theoretical analysis. At last, experiments of the dummy load applied to the high power spiral pulse forming line were performed; a quasisquare pulse voltage is obtained at the dummy load.

Yin, Yi; Zhong, Hui-Huang; Liu, Jin-Liang; Ren, He-Ming; Yang, Jian-Hua; Zhang, Xiao-Ping; Hong, Zhi-Qiang

2010-09-01

177

Radial current high power dummy load for characterizing the high power laser triggered transformer-type accelerator.  

PubMed

A radial-current aqueous resistive solution load was applied to characterize a laser triggered transformer-type accelerator. The current direction in the dummy load is radial and is different from the traditional load in the axial. Therefore, this type of dummy load has smaller inductance and fast response characteristic. The load was designed to accommodate both the resistance requirement of accelerator and to allow optical access for the laser. Theoretical and numerical calculations of the load's inductance and capacitance are given. The equivalent circuit of the dummy load is calculated in theory and analyzed with a PSPICE code. The simulation results agree well with the theoretical analysis. At last, experiments of the dummy load applied to the high power spiral pulse forming line were performed; a quasisquare pulse voltage is obtained at the dummy load. PMID:20886974

Yin, Yi; Zhong, Hui-Huang; Liu, Jin-Liang; Ren, He-Ming; Yang, Jian-Hua; Zhang, Xiao-Ping; Hong, Zhi-qiang

2010-09-01

178

Development and testing of a fast Fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization  

NASA Astrophysics Data System (ADS)

A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200 000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range.

Thoen, D. J.; Bongers, W. A.; Westerhof, E.; Oosterbeek, J. W.; de Baar, M. R.; van den Berg, M. A.; van Beveren, V.; Bürger, A.; Goede, A. P. H.; Graswinckel, M. F.; Hennen, B. A.; Schüller, F. C.

2009-10-01

179

Characterization of RNA from Noninfectious Virions Produced by Sarcoma Positive-Leukemia Negative Transformed 3T3 Cells  

PubMed Central

RNA from noninfectious virions produced by two established clonal lines of sarcoma positive-leukemia negative (S+L-)-transformed 3T3 cells has been characterized. RNA from virions or nucleoids of S+L--(C243) cells consisted of three to four sizes: ±44 S (6%), 28 S (17%), 18 S (38%), and <18 S (39%). 28S virion RNA contained some virus-specific information demonstrable by RNA·DNA hybridization with a DNA probe derived from the RNA-directed DNA polymerase product of murine sarcoma-leukemia virus, while parallel studies indicated that 28S ribosomal RNA from ribosomal subunits of transformed and nontransformed 3T3 cells did not contain virus-specific information. In contrast to the S+L-(C243) virions, RNA from virions or nucleoids of S+L-(D56) cells consisted of five sizes: 80 S (6%), 68 S (8%), 56 S (5%), 28 S (28%), and <28 S (53%). Thermal dissociation studies suggested that this S+L- genome is comprised of 28S RNA subunits. From these studies we postulate that the 28S viral RNA is most probably the monomeric genome of S+L- virions.

Phillips, Leo A.; Hollis, Vincent W.; Bassin, Robert H.; Fischinger, Peter J.

1973-01-01

180

Long-term batch study of sorption, transformation and extractability to characterize the fate of the veterinary antibiotic sulfadiazine  

NASA Astrophysics Data System (ADS)

The occurrence of veterinary antibiotic substances in various environmental compartments is of growing concern. Once released into the environment (e.g. via manure), these organic substances can cause changes in the composition of microbial populations, provoke the development and spreading of resistance genes and finally reach the food chain. The substance under study is the veterinary antibiotic sulfadiazine (SDZ), which belongs to the chemical group of the sulfonamides. These compounds are widely applied in animal husbandry. There are hardly any studies on the macroscopic sorption and desorption behaviour in combination with transformation processes, particularly investigating the sorbed fraction. We are conducting long-term batch sorption experiments to characterize the partitioning between the liquid and the solid phases as well as formation of transformation products. A sequential extraction procedure enables us to analyse the composition of the various sorbed fractions. We applied 14C-labelled SDZ in aqueous solution to fresh soil, originating from an agricultural field (silty loam). Adsorption and desorption studies are conducted for the duration of 60 d and 80 d, respectively. Unique setups for single time-steps allow us to trace the development of the partition process between the liquid and the solid phase and also partitioning within the solid phase. The composition of these liquid phases concerning the parent substance and the transformation products is analyzed. Using Radio-HPLC we find at least five transformation products: 4-hydroxy-sulfadiazine (4-OH-SDZ), 4-(2-iminopyrimidin-1(2H)-yl)-aniline (An-SDZ) and additionally three yet unknown products. By means of a sequential extraction, differently strong bound fractions of the compound can be distinguished. Extractions consist of a mild method (0.01 M CaCl2-solution; 24 h) followed by a methanol extraction (4 h). Finally, a residual fraction is gained by microwave extraction at an elevated temperature (150°C) and pressure (mixture of water and acetonitril, 4:1). Bound residues are determined by combustion. The course of the kinetic adsorption/desorption processes as well as the partitioning of the compound over the various solid phase fractions is observed. Sorption is time-dependent and strongly non-linear. The topsoil shows a significantly higher sorption affinity than the subsoil. While the amount of radioactivity sorbed to the soil matrix increases with time, the extractability decreases significantly, i. e. at the end of the experimental time there is no yield with mild extraction methods. On the contrary, after 60 d, there is still a considerably mass gained with the microwave extraction. Desorption is very slow due to hysteresis. In the topsoil transformation occurs with higher rates, leading to more detectable transformation products as in the subsoil. With our experimental setup it will be possible to set up a kinetic modell for the partitioning of the solute between the liquid and the solid phase. This description will also include an estimation of the transformation parameters.

Sittig, Stephan; Kasteel, Roy; Groeneweg, Joost; Vereecken, Harry

2010-05-01

181

Plant bio-transformable HMG-CoA reductase gene loaded calcium phosphate nanoparticle: in vitro characterization and stability study.  

PubMed

Encapsulation of plasmid DNA in nanoparticle is expected to enhance the stability of DNA, reproducibility and frequency of the genetic transformation in plants. Here we report the formulation of HMG Co-A reductase gene loaded calcium phosphate nanoparticles (Cap nanoparticles) and their in-vitro, in-vivo characterization. The developed Cap nanoparticles were characterized by DSC, FT-IR, and XRD. Developed Cap nanoparticles were spherical in shape having the particle size and zeta potential in the range of 10.86±0.09nm to 33.42±0.18nm and -25.5±0.07mV to -31.7±0.07mV (for Cap-I to Cap-IV). DNA releasing in acidic media showed, initially slow release followed by fast release with a maximum release of Cap-I (95.77±1.39%) > Cap-II (87.32±2.07%) > Cap-III (76.54±2.01%) > Cap-IV (72.93±1.75%) over 60min. Cap nanoparticles were quite stable at storage condition of 40±0.5°C/75±5%RH, 25±0.5°C/60±RH, 4±0.5°C/ambient humidity and the integrity of pDNA encapsulated was confirmed by gel electrophoresis. Compared to wild type C. intybus, transformation efficiency and enhanced biosynthesis of esculin with the DNA nanoparticles in C. intybus were about 10% and 71%, respectively. Antioxidant activity capacity of the biotransformed plants was significantly higher than the normal plant due to high accumulation of esculin. PMID:22564167

Ohadi R, Mehrnaz S; Alvari, Amene; Samim, M; Abdin, Malik Z

2013-03-01

182

Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution  

NASA Astrophysics Data System (ADS)

This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm × 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45° beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

Laroche, G.; Vallade, J.; Bazinette, R.; van Nijnatten, P.; Hernandez, E.; Hernandez, G.; Massines, F.

2012-10-01

183

Isolation and characterization of mink lung epithelial cell mutants resistant to transforming growth factor. beta  

SciTech Connect

Mink lung epithelial cells resistant to growth inhibition by transforming growth factor ..beta.. (TGF-..beta..) have been isolated by chemical mutagenesis and growth in the presence of platelet extracts enriched in TGF-..beta... Several resistant clones were isolated, at least one of which stably retained its resistance to TGF-..beta.. when grown in the absence of the factor. The cells of this clone were similar to the parent cells in morphology and growth properties. However, unlike the parent cells, the resistant cells did not show any of the following responses to /sup 125/I TGF-..beta..: (1) inhibition of DNA synthesis and proliferation; (2) morphological changes involving increased cell spreading; or (3) stimulation of synthesis of a 48-kilodalton secreted /sup 35/S-protein. The resistant cells do, however, retain a functional TGF-..beta.. receptor. The TGF-..beta.. resistant cell lines may be useful in genetic studies designed to identify the biochemical events required for inhibition of epithelial cell growth by this factor.

Chinkers, M.

1987-01-01

184

Transformation strain based method for characterization of convective heat transfer from shape memory alloy wires  

NASA Astrophysics Data System (ADS)

While shape memory alloys (SMAs) have many actuation benefits, their frequencies are commonly restricted by slow cooling times caused by limitations in convective heat transfer. To increase the cooling speed and at the same time reduce excess power consumption from overheating, it is critical to understand the heat transfer from SMA wires. This requires accurate surface temperature measurement under a fixed input power, which is difficult to obtain using traditional methods because of the nature of SMAs (thin wires, large strains, heat activation, ambient environment, etc). This paper introduces a non-invasive technique for calculating the convective coefficient for SMAs by employing the temperature-induced transformation strain of SMAs to estimate the surface temperature. This method was experimentally validated for measurement of the convective coefficient in air where infrared cameras can operate, and then used to indirectly measure the convective coefficient across a range of commonly utilized SMA wire diameters and ambient media where traditional methods are limited. Formulated empirical correlations to the collected data provide a mathematical relationship to calculate the convective coefficient in material models which serve as better estimates of convection, and may be used for optimization of SMA actuators for increased frequency performance while ensuring that power draw is minimized.

Pathak, Anupam; Brei, Diann; Luntz, Jonathan

2010-03-01

185

Isolation and characterization of efficient isoxaben-transforming Microbacterium sp strains from four European soils.  

PubMed

Nutrient-agar plates containing isoxaben (500 mg litre(-1)) were used to isolate isoxaben-metabolising bacteria from four European soils incubated with the herbicide under laboratory conditions. In flask experiments, inoculation of a basal salts medium containing nitrogen and [phenyl-U-14C]isoxaben with an isolate (B2b) resulted in 33% recovery of the initial radioactivity as [14C]carbon dioxide after 2 weeks. A major metabolite identified by GC-MS and NMR analysis as 3-(1-ethyl-1-methylpropyl)isoxazol-5-ylamine accumulated both in basal salts and nutrient broth media. 2,6-Dimethoxybenzoic acid, a suspected metabolite of isoxaben, was not detected in either liquid media. However, the capability of the B2b isolate to use 2,6-dimethoxybenzoic acid as a source of carbon was demonstrated. Soil inoculation with the B2b strain resulted in an increase in the recovery of [14C] carbon dioxide from both [phenyl-U-14C] and [isoxazole-5-14C]isoxaben. The metabolite identified as 3-(1-ethyl-1-methylpropyl)isoxazole-5-ylamine only accumulated if the soil was autoclaved before inoculation. This metabolite was rapidly mineralized by the microflora of a natural soil without history of isoxaben treatment. Homology patterns of sequenced 16S rDNA between isoxaben-transforming isolates and reference strains showed that the four isolates identified belonged to the genus Microbacterium. PMID:12476996

Arrault, Sandra; Desaint, Stephane; Catroux, Colette; Sémon, Etienne; Mougin, Christian; Fournier, Jean Claude

2002-12-01

186

DNA binding to crystalline silica characterized by Fourier-transform infrared spectroscopy.  

PubMed

The interaction of DNA with crystalline silica in buffered aqueous solutions at physiologic pH has been investigated by Fourier-transform infrared spectroscopy (FT-IR). In aqueous buffer, significant changes occur in the spectra of DNA and silica upon coincubation, suggesting that a DNA-silica complex forms as silica interacts with DNA. As compared to the spectrum of silica alone, the changes in the FT-IR spectrum of silica in the DNA-silica complex are consistent with an Si-O bond perturbation on the surface of the silica crystal. DNA remains in a B-form conformation in the DNA-silica complex. The most prominent changes in the DNA spectrum occur in the 1225 to 1000 cm-1 region. Upon binding, the PO2- asymmetric stretch at 1225 cm-1 is increased in intensity and slightly shifted to lower frequencies; the PO2- symmetric stretch at 1086 cm-1 is markedly increased in intensity and the band at 1053 cm-1, representing either the phosphodiester or the C-O stretch of DNA backbone, is significantly reduced in intensity. In D2O buffer, the DNA spectrum reveals a marked increase in intensity of the peak at 1086 cm-1 and a progressive decrease in intensity of the peak at 1053 cm-1 when DNA is exposed to increasing concentrations of silica. The carbonyl band at 1688 cm-1 diminishes and shifts to slightly lower frequencies with increasing concentrations of silica. The present study demonstrates that crystalline silica binds to the phosphate-sugar backbone of DNA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7705292

Mao, Y; Daniel, L N; Whittaker, N; Saffiotti, U

1994-12-01

187

Aqueous uranium(VI) hydrolysis species characterized by attenuated total reflection Fourier-transform infrared spectroscopy.  

PubMed

The speciation of uranium(VI) in micromolar aqueous solutions at ambient atmosphere was studied by attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy and by speciation modeling applying the updated NEA thermodynamic database. It can be shown that reliable infrared spectra of micromolar U(VI) solutions are obtained abolishing the restrictions of previous spectroscopic investigations to millimolar concentrations and, consequently, to the acidic pH range. A significant change of the U(VI) speciation can be derived from the spectral alterations of the absorption band representing the antisymmetric stretching mode (nu3) of the UO2(2+) ion observed upon lowering the U(VI) concentration from the milli- to the micromolar range at a constant pH 4 value. The acquisition of spectra of diluted U(VI) solutions allows the increase of the pH up to 8.5 without the risk of formation of colloidal or solid phases. The infrared spectra are compared to the results of the computed speciation patterns. Although a complete interpretation of the spectra can not be given at this state of knowledge, the spectral data strongly suggest the presence of monomeric U(VI) hydroxo species already showing up at a pH value > or = 2.5 and dominating the speciation at pH 3. This is in contradiction to the predicted speciation where the fully hydrated UO2(2+) is expected to represent the main species at pH values below 4. At ambient pH, a more complex speciation is suggested compared to the results of the computational modeling technique. The predicted dominance of the UO2(CO3)3(4-) complex at pH > or = 8 was not confirmed by the infrared data. However, the infrared spectra indicate the formation of hydroxo complexes obviously containing carbonate ligands. PMID:18831578

Müller, Katharina; Brendler, Vinzenz; Foerstendorf, Harald

2008-10-03

188

A Novel High Performance Fourier Transform Ion Cyclotron Resonance Cell for Improved Biopolymer Characterization  

SciTech Connect

A new trapped ion cell design for use with Fourier transform ion cyclotron resonance mass spectrometry is described. The design employs 15 cylindrical ring electrodes to generate trapping potential wells and 32 separately assignable rod electrodes for excitation and detection. The rod electrodes are positioned internal to the ring electrodes and provide excitation fields that are thereby linearized along the magnetic field over the entire trapped ion volume. The new design also affords flexibility in the shaping of the trapping field using the 15 ring electrodes. Many different trapping well shapes can be generated by applying different voltages to the individual ring electrodes, ranging from quadratic to linearly ramped along the magnetic field axis, to a shape that is nearly flat over the entire trap volume, but rises very steeply near the ends of the trap. This feature should be useful for trapping larger ion populations and extension of the useful range of ion manipulation and dissociation experiments since the number of stages of ion manipulation or dissociation is limited in practice by the initial trapped ion population size. Predicted trapping well shapes for two different ring electrode configurations are presented and these and several other possible configurations are discussed, as are the predicted excitation fields based on the use of rod electrodes internal to the trapping ring electrodes. Initial results are presented from an implementation of the design using a 3.5 T superconducting magnet. It was found that ions can be successfully trapped and detected with this cell design and that selected ion accumulation can be performed with the utilization of four rods for quadrupolar excitation. The initial results presented here illustrate the feasibility of this cell design and demonstrate differences in observed performance based upon different trapping well shapes.

Bruce, James E. (BATTELLE (PACIFIC NW LAB)); Anderson, Gordon A. (BATTELLE (PACIFIC NW LAB)); Lin, Chuan-Yuan (ASSOC WESTERN UNIVERSITY); Gorshkov, Michael V. (OFFICE OF FELLOWSHIP PROG); Rockwood, Alan L. (BATTELLE (PACIFIC NW LAB)); Smith, Richard D. (BATTELLE (PACIFIC NW LAB))

2000-02-22

189

DNA binding to crystalline silica characterized by Fourier-transform infrared spectroscopy.  

PubMed Central

The interaction of DNA with crystalline silica in buffered aqueous solutions at physiologic pH has been investigated by Fourier-transform infrared spectroscopy (FT-IR). In aqueous buffer, significant changes occur in the spectra of DNA and silica upon coincubation, suggesting that a DNA-silica complex forms as silica interacts with DNA. As compared to the spectrum of silica alone, the changes in the FT-IR spectrum of silica in the DNA-silica complex are consistent with an Si-O bond perturbation on the surface of the silica crystal. DNA remains in a B-form conformation in the DNA-silica complex. The most prominent changes in the DNA spectrum occur in the 1225 to 1000 cm-1 region. Upon binding, the PO2- asymmetric stretch at 1225 cm-1 is increased in intensity and slightly shifted to lower frequencies; the PO2- symmetric stretch at 1086 cm-1 is markedly increased in intensity and the band at 1053 cm-1, representing either the phosphodiester or the C-O stretch of DNA backbone, is significantly reduced in intensity. In D2O buffer, the DNA spectrum reveals a marked increase in intensity of the peak at 1086 cm-1 and a progressive decrease in intensity of the peak at 1053 cm-1 when DNA is exposed to increasing concentrations of silica. The carbonyl band at 1688 cm-1 diminishes and shifts to slightly lower frequencies with increasing concentrations of silica. The present study demonstrates that crystalline silica binds to the phosphate-sugar backbone of DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Mao, Y; Daniel, L N; Whittaker, N; Saffiotti, U

1994-01-01

190

Validation of antibody-based recognition by piezoelectric transducers through electroacoustic admittance analysis  

Microsoft Academic Search

The development of immunosensors based on piezoelectric transducers is widely investigated due to their attractive potentialities. The quartz crystal microbalance (QCM) may give a direct response signal which characterizes the binding event between a sensitive layer, immobilized onto the surface transducer, and the analyte to be detected. However, for small biomolecules, such as some antigens, it is quite difficult to

K. Bizet; C. Gabrielli; H. Perrot; J. Therasse

1998-01-01

191

Yeast two-hybrid system for studying protein-protein interactions--stage 2: Transforming and characterizing the library.  

PubMed

An important element in the characterization of the function of a protein is the identification of other proteins with which it interacts. A powerful genetic strategy for this purpose, termed the "yeast two-hybrid system," uses transcriptional reporters in yeast to indirectly reflect the interaction between two proteins. The term "two-hybrid" derives from the two classes of chimeric, or "hybrid," proteins used in each screen. The first, commonly referred to as the "bait," is a fusion of a protein of interest "x" with a DNA-binding domain (DBD-x). The second, sometimes called the "prey," is a fusion of a cDNA library "y" to a transcriptional activation domain (AD-y). Together, DBD-x and AD-y provide the basis of the detection system. The two-hybrid approach has gained wide popularity because of the relative ease and speed with which it can be used to identify novel protein-protein interactions and to analyze known interactions. The second stage of the method, described in this protocol, includes the transformation of yeast with a cDNA library, followed by library characterization. It can be performed in parallel with construction of a bait protein (stage 1). PMID:20439417

Serebriiskii, Ilya

2010-05-01

192

Synthesis of dual-band bandpass filters using successive frequency transformations and circuit conversions  

Microsoft Academic Search

A novel method is proposed to synthesize dual-band bandpass filters (BPFs) from a prototype low-pass filter. By implementing successive frequency transformations and circuit conversions, a new filter topology is obtained which consists of only admittance inverters and series resonators, and is thereby easy to be realized by using conventional distributed elements. A dual-band BPF with center frequencies of 1.8GHz and

Xuehui Guan; Zhewang Ma; Peng Cai; Yoshio Kobayashi; Tetsuo Anada; Gen Hagiwara

2006-01-01

193

Hydrothermal synthesis and characterization of a zigzag chain and transformation between isomeric iron–sulfate chains  

Microsoft Academic Search

A new organically directed iron sulfate (C6N2H14)[Fe(SO4)2(OH)]·H2O with zigzag chains has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy and thermo-gravimetric analysis. The compound crystallizes in monoclinic space group C2\\/c, crystal data: a=18.6419(18)Å, b=12.0129(12)Å, c=12.4794(12)Å, ?=108.275(2), V=2653.7(4)Å3, Z=8, M=395.17. The inorganic moiety of the title compound is constructed from the tancoite-type unit

Yunlong Fu; Yu Zhang; Zhiwei Xu

2008-01-01

194

Determination of interface states and their time constant for Au/SnO2/n-Si (MOS) capacitors using admittance measurements  

NASA Astrophysics Data System (ADS)

The frequency dependence of admittance measurements (capacitance-voltage (C-V) and conductance-voltage (G/?-V)) of Au/SnO2/n-Si (MOS) capacitors was investigated by taking into account the effects of the interface states (Nss) and series resistance (Rs) at room temperature. Admittance measurements were carried out in frequency and bias voltage ranges of 1 kHz-1 MHz and (-5 V)-(+9 V), respectively. The values of Nss and Rs were determined by using a conductance method and estimating from the admittance measurements of the MOS capacitors. At low frequencies, the interface states can follow the AC signal and yield excess capacitance and conductance. In addition, the parallel conductance (Gp/?) versus log(f) curves at various voltages include a peak due to the presence of interface states. It is observed that the Nss and their time constant (?) range from 1.23 × 1012 eV-1 cm-2 to 1.47 × 1012 eV-1 cm-2 and from 7.29 × 10-5 s to 1.81 × 10-5 s, respectively.

M. Baran, H.; Tataro?lu, A.

2013-04-01

195

Fourier Transform Infrared Characterization of Moisture Absorption in SiOF Films  

NASA Astrophysics Data System (ADS)

In this paper, the water absorption characteristics of as-deposited and annealed liquid-phase-deposited fluorinated silicon oxide (LPD-SiOF) films were investigated to clarify the film properties. The stability of moisture absorption was characterized under an air-exposure environment of 23°C and 65% humidity. The as-deposited LPD-SiOF film was found to easily absorb moisture from air and therefore to become unstable in terms of the dielectric property. To obtain a highly stable dielectric film, a hydrofluosilicic acid concentration of 2.2 M (with the corresponding fluorine content of 4.9 at.%) is suggested because it has a minimum water absorption change (<3%). The related OH concentration was comparable (or even smaller) to those of other SiOF films grown by chemical vapor deposition. Moreover, high-temperature annealing in nitrogen ambient was utilized to drive out the moisture absorbed in an LPD-SiOF film. The annealing process after deposition tends to render the film surface hydrophobic. The resulting OH bonds were found to disappear after annealing and did not reappear even after long time of air exposure.

Chang, Wai-Jyh; Houng, Mau-Phon; Wang, Yeong-Her

1999-08-01

196

The change in the acoustic admittance phase angle: a study in children suffering from acute otitis media.  

PubMed

Middle ear mechanics, in normal and in pathological conditions, is the subject of this research, with acoustic impedance measurements as the cornerstone. Previous studies have established the importance of admittance-phase tympanograms, mainly in frequencies higher than the conventional 226 Hz. The purpose of the present study was to record how acute otitis media (AOM) affects the middle ear system and function by evaluating the recordings of the change in phase angle parameter (deltatheta) provided by an automated tympanometer using the sweep-frequency technique. Multifrequency and conventional tympanograms were obtained from 70 children suffering from AOM on consecutive visits. Values of deltatheta from these subjects were compared to normative data previously acquired in our Department. It appears that changes in the mechanical status of the middle ear after AOM are reflected in abnormal deltatheta values, despite the normal findings of conventional tympanometry. A positive history of AOM did not seem to influence the behaviour of the middle ear. In most cases, abnormal deltatheta values coexisted with abnormal values of resonance frequency (RF), i.e. the frequency at which mass and stiffness of the middle ear are in balance, and total susceptance (deltaB) reaches 0mmhos and the converse. The deltatheta seems to be an important indicator of middle ear mechanical status that can record changes occurring in the system after AOM and undetected by low probe-tone tympanometry. PMID:11330915

Vlachou, S G; Tsakanikos, M; Douniadakis, D; Apostolopoulos, N

2001-01-01

197

Transformation 2 - Transformation Methods  

NSDL National Science Digital Library

This lesson explains the procedure of introducing a new gene into a plant cell (transformation). It discusses the main goals of the transformation process and describes the four main methods of transformation.

198

Fourier transform ion cyclotron resonance mass spectral characterization of metal-humic binding.  

PubMed

The interaction between metals and naturally occurring humic substances and the thereby induced issues of bioavailability and hydrogeochemical turnover of metal ions in natural waters have been the subject of intense study for decades. Traditional bulk techniques to investigate metal-humic binding (e.g. potentiometry and inductively coupled plasma mass spectrometry (ICP-MS)) can provide quantitative results for the relative abundance and distribution of metal species in humic samples and/or overall binding constants. The shortcoming of these bulk techniques is the absence of structural detail. Ultra-high-resolution mass spectrometry, currently the only technique demonstrated to resolve individual humic ions, is not generally employed to provide the missing qualitative information primarily because the identification of metal complexes within the already complex mixtures of humic substances is non-trivial and time-consuming to the extent of eliminating any possibility for real-time manipulation of chelated analytes. Here, it is demonstrated that with tailored selection of the metal ion, it is possible to visually identify large numbers of metal-humic complexes ( approximately 500 for Be2+, approximately 1100 for Mn2+, and approximately 1500 for Cr3+) in real-time as the spectra are being acquired. Metal ions are chosen so that they form primarily even-m/z complexes with humic ions. These even-m/z complexes stand out in the spectrum and can readily be characterized based on molecular formulae, which here revealed for example that Suwannee River fulvic acid (SRFA) complexes encompassed primarily highly oxygenated fulvic acids of relatively low double-bond equivalence. Facile, real-time identification of even-m/z metal-humic complexes additionally allows for the specific selection of metal-humic complexes for MS(n) analysis and in-trap ion-neutral reactions enabling investigation of metal-humic complex structure. MS/MS data were collected to demonstrate the potential of the technique as well as highlight some of the remaining challenges. PMID:19142858

Stenson, Alexandra C

2009-02-01

199

Synthesis and characterization of catalysts for the selective transformation of biomass-derived materials  

NASA Astrophysics Data System (ADS)

The experimental work in this thesis focuses on generating catalysts for two intermediate processes related to the thermal conversion of lignocellulosic biomass: the synthesis and characterization of mesoporous silica supported cobalt catalysts for the Fischer-Tropsch reaction, and an exploration of the reactivity of bulk and supported molybdenum-based nitride catalysts for the hydrodeoxygenation (HDO) of guaiacol, a lignin model compound. The first section of the work details the synthesis of a series of silica-supported cobalt Fischer-Tropsch catalysts with pore diameters ranging from 2-23 nm. Detailed X-ray diffraction measurements were used to determine the composition and particle diameters of the metal fraction, analyzed as a three-phase system containing Cofcc, Cohcp and CoO particles. Catalyst properties were determined at three stages in catalyst history: (1) after the initial calcination step to thermally decompose the catalyst precursor into Co3O4, (2) after the hydrogen reduction step to activate the catalyst to Co and (3) after the FT reaction. From the study, it was observed that larger pore diameters supported higher turnover frequency; smaller pore diameters yielded larger mole fraction of CoO; XRD on post-reduction and post-FTS catalyst samples indicated significant changes in dispersivity after reduction. In the next section, the catalytic behaviors of unsupported, activated carbon-, alumina-, and SBA-15 mesoporous silica-supported molybdenum nitride catalysts were evaluated for the hydrodeoxygenation of guaiacol (2-methoxy phenol) at 300°C and 5 MPa. The nitride catalysts were prepared by thermal decomposition of bulk and supported ammonium heptamolybdate to form MoO 3 followed by nitridation in either flowing ammonia or a nitrogen/hydrogen mixture. The catalytic properties were strongly affected by the nitriding and purging treatment as well as the physical and chemical properties of support. The overall reaction was influenced by the crystalline phase present in the catalyst, dispersion of molybdenum nitride/oxynitride, and the porosity of the support. The hydrodeoxygenation of guaiacol followed two proposed reaction pathways: demethylation (DME) of guaiacol to form catechol, followed by dehydroxylation to form phenol; or a direct demethoxylation (DMO) to form phenol. The selectivity of the reaction was expressed in terms of the phenol/catechol ratio. Phenol was the predominant product for all the catalysts studied, except for the alumina-supported catalysts (an effect of the alumina support). The results from this thesis are encouraging for the application of Mo nitride based catalysts for hydrodeoxygenation of whole pyrolysis oil.

Ghampson, Isaac Tyrone

200

Characterization of vegetable oils: detailed compositional fingerprints derived from electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Adulteration of vegetable oil is of concern for both commercial and health reasons. Compositional based fingerprints can potentially reveal both the oil source and its possible adulteration. Here, electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) resolves and identifies literally thousands of distinct chemical components of commercial canola, olive, and soybean oils, without extraction or other wet chemical separation pretreatment. In negative-ion ESI FT-ICR MS, the acidic components of soybean oil are easily distinguished from those of canola and olive oil based on relative abundances of C(18) fatty acids, whereas olive oil differs from canola and soybean oil based on relative abundances of tocopherols. In positive-ion ESI FT-ICR MS, the three oils are readily distinguished according to the relative abundances of di- and triacylglycerols with various numbers of double bonds in the fatty acid chains. We demonstrate the detection of soybean oil as an adulterant of olive oil, based on relative abundances of members of each of several chemical families. We suggest that the detailed chemical compositions of vegetable oils can be used to characterize them and to detect and identify adulterants. PMID:15315364

Wu, Zhigang; Rodgers, Ryan P; Marshall, Alan G

2004-08-25

201

A Paraneoplastic Syndrome Characterized by Extremity Swelling with Associated Inflammatory Infiltrate Heralds Aggressive Transformation of Myelodysplastic Syndromes/Myeloproliferative Neoplasms to Acute Myeloid Leukemia: A Case Series  

PubMed Central

There has been a long history of reports describing a variety of paraneoplastic phenomena associated with myelodysplastic syndromes, particularly those with autoimmune manifestations. We report here a series of patients with an antecedent myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN) that underwent aggressive transformation to acute myeloid leukemia (AML). In each case, the transformation to AML was preceded by an inflammatory syndrome characterized by unilateral extremity swelling and an associated inflammatory skin infiltrate, as well as other signs of inflammation, including profound hyperferritinemia without evidence of a hemophagocytic syndrome. We suggest that such an inflammatory syndrome may herald aggressive transformation of MDS/MPN to AML. Patients with known MDS/MPN who present with these features may benefit from early bone marrow examination to assess disease status. Early intervention with corticosteroids in select patients may result in improvement or resolution of the symptoms and permit intensive therapy for AML to be delivered.

Mangan, James K.; Luger, Selina M.

2012-01-01

202

Application of Hilbert-Huang transform to characterize soil liquefaction and quay wall seismic responses modeled in centrifuge shaking-table tests  

Microsoft Academic Search

In this paper, a Hilbert-Huang Transform data-processing technique is successfully used to characterize the seismic responses of soil–quay wall systems using measured data in a series of geotechnical centrifuge shaking-table tests. The predominant frequency of a liquefied deposit shifts down to a low frequency level; however, “de-liquefaction” leads to frequent, local higher-frequency spikes in the time histories of predominant instantaneous

Yu-Chen Wei; Chung-Jung Lee; Wen-Yi Hung; Huei-Tsyr Chen

2010-01-01

203

Natural Transformation in Mesophilic and Thermophilic Bacteria: Identification and Characterization of Novel, Closely Related Competence Genes in Acinetobacter sp. Strain BD413 and Thermus thermophilus HB27  

Microsoft Academic Search

The mesophile Acinetobacter sp. strain BD413 and the extreme thermophile Thermus thermophilus HB27 display high frequencies of natural transformation. In this study we identified and characterized a novel competence gene in Acinetobacter sp. strain BD413, comA, whose product displays significant similarities to the competence proteins ComA and ComEC in Neisseria and Bacillus species. Transcription of comA correlated with growth phase-dependent

ALEXANDRA FRIEDRICH; THOMAS HARTSCH; BEATE AVERHOFF

2001-01-01

204

Étude par spectroscopie d'admittance et MEB de la dégradation électrique des couches minces de CuAlS{2} non dopé déposées sous vide  

NASA Astrophysics Data System (ADS)

We have accelerated the ageing of CuAlS2 by the application of a static electrical field for different degradation times. We have investigated the admittance spectroscopy and the scanning electron microscopy to follow and understand the (mass-charge) coupled transport processes produced in the volume and on the surface of these films. The electrical constraint induces, after an incubation phase, an activated decrease of the resistance, followed by a susbstantial increase correlated to the formation of an open circuit. This degradation occurs more rapidly for the films having initially a lower resistance, due to the thermal dissipation which increases considerably the temperature to about 140 °C. Admittance spectra reveal, at low frequencies, a capacitive loop related to the formation of a charge space induced by copper diffusion. Such migration develop induces the formation of copper arborescences, spreading from the cathode towards the anode. The effect of these structures on the properties of the degraded films is discussed in relation to electromigration and associated processes (whiskers, fracture, healing, bridge-building, ...). Also, we have noticed their similarity with fractal phenomena such as electrodeposition and dielectric breakdown. Nous avons accéléré le vieillissement des couches minces de CuAlS2 par l'application d'un champ électrique statique pendant des durées variables. Nous avons fait appel à la spectroscopie d'admittance et la microscopie électronique à balayage, pour suivre et comprendre les processus de transport couplé (masse- charge) qui se produisent en volume et en surface de ces couches. L'effet de la contrainte électrique s'est traduit, après une phase d'incubation, par une décroissance activée de la résistance, suivie d'une phase d'emballement reliée à la formation d'un circuit ouvert. Cette fracturation se manifeste plus rapidement pour les couches ayant initialement une faible résistance, suite à l'effet de la dissipation thermique qui peut augmenter notablement leur température (140 °C). Les spectres d'admittance révèlent, vers les basses fréquences, une boucle capacitive reliée à la formation d'une charge d'espace induite par la diffusion du cuivre. Une telle migration développe, sur la surface depuis la cathode, des arborescences de cuivre orientées vers l'anode. L'effet de ces structures sur les propriétés des couches dégradées a été discuté en mettant en cause le phénomène d'électromigration et ses mécanismes associés (whiskers, fracture, “healing", pontage, ...). De même, nous avons noté leur similarité avec des phénomènes fractals tels que l'électrodéposition ou le claquage diélectrique.

Helali, N.; Bouricha, B.; Rezig, B.

1998-07-01

205

Relationship between Dielectric Properties and Admittance Spectra of Oxide Ion Conductor Ce0.9Y0.1O2-?  

NASA Astrophysics Data System (ADS)

The frequency dependences of the dielectric properties \\varepsilonr{}' and \\varepsilonr{}'' for 10 at. % Y-doped CeO2 (Ce0.9Y0.1O2-?), which is a typical oxide-ion conductor, were investigated in a frequency range from 5 Hz to 13 MHz and in a temperature range from 673 to 1073 K in air. The complex dielectric constants were successfully analyzed, assuming both the polarizations of dopant-vacancy associates and charging or loss currents. The dielectric parameters estimated from the frequency dependences of dielectric constants were discussed in relation to admittance spectra, in addition to ac conductivity (?ac) and dielectric loss tangent (\\tan?).

Yamamura, Hiroshi; Satake, Jun; Saito, Miwa

2010-10-01

206

Isolation and immunological characterization of an iron-regulated, transformation-sensitive cell surface protein of normal rat kidney cells.  

PubMed

We have analyzed the surfacr proteins of cultured normal rat kidney (NRK) cells and virus-transformed NRK cells subjected to iron deprivation. Such a treatment specifically induces two transformation-sensitive plasma membrane-associated glycoproteins with a subunit molecular weight of 160,000 (160 K) and 130,000 (130 K) daltons in NRK cells. In these cells the 160 K glycoprotein is readily available to lactoperoxidase-mediated iodination, and the 130 K is apparently inaccessible to iodination. Major differences were revealed when iodinated membrane proteins of normal and virus-transformed cells subjected to iron deprivation were compared. In Kirsten sarcoma virus-transformed NRK cells the 160 K glycoprotein was weakly labeled. In two clones of simian virus 40-transformed NRK cells the 160 K glycoprotein was weakly labeled or not at all. The 130 K glycoprotein was inaccessible to iodination in all virus-transformed cell lines. The 160 K and 130 K glycoproteins were isolated from plasma membranes of NRK cells using preparative SDS gel electrophoresis. Antibodies generated against these glycoproteins stained the external surfaces of NRK cells and induced antigen redistribution. Evidence presented suggests that 160 K and 130 K are plasma membrane-associated procollagen molecules. A possible interaction of these proteins with transferrin is also described. The data suggest that these proteins may have an important role in the sequence of events leading to transformation. PMID:232520

Fernandez-Pol, J A

1979-01-01

207

Deep level defect studies in semi-insulating 4H- and 6H-silicon carbide using optical admittance spectroscopy  

NASA Astrophysics Data System (ADS)

The objective of this study is to determine the deep vanadium defect levels in semi-insulating 4H- and 6H- silicon carbide using optical admittance spectroscopy. Also infrared spectroscopy and electron paramagnetic resonance spectroscopy are conducted to support the evidence of vanadium donor and acceptor levels obtained from OAS measurements. Vanadium acts as an amphoteric impurity in silicon carbide with a V3+/4+ acceptor level and V4+/5+ donor level. Although the value for the donor level is well established, the V3+/4+ defect level remains controversial. OAS shows that the vanadium donor level is isolated near Ec-1.7 eV, and the vanadium acceptor level is located at Ec-0.75 eV at a cubic site and Ec-0.94 eV at a hexagonal site in 4H-SiC, while the vanadium donor level of 6H-SiC samples is about Ec-1.5 eV. The acceptor levels of 6H-SiC were assigned to Ec-0.67 eV, E c -0.70 eV at two cubic sites, and Ec-0.87 eV at a hexagonal site. IR spectra demonstrated that the signatures of the vanadium V 3+ and V4+ charge states are present in the samples. EPR and photo-induced EPR are used to identify the V3+/4+ and V4+/5+ levels as well as the V3+ and V 4+ charge states. EPR spectra represent both V3+ and V4+ in 4H- and 6H samples consistent with FTIR data. EPR and photo-induced EPR suggest that the va nadium acceptor level is between 0.7 eV and 0.86 eV, while the donor level is near Ec-1.5 eV in 6H-SiC. The donor level of 4H-SiC is located at Ec-1.6 eV. Thus, the data obtained from EPR and FTIR support the assignment of the vanadium defect levels determined by OAS. Vanadium complexes induced by other elements such as titanium, hydrogen, and nitrogen atoms are also observed in OAS spectra and will be discussed in the text.

Lee, Wonwoo

208

Carbonmonoxy dopamine beta-hydroxylase. Structural characterization by Fourier transform infrared, fluorescence, and x-ray absorption spectroscopy.  

PubMed

The carbon monoxide complex of ascorbate-reduced dopamine beta-hydroxylase has been prepared and characterized by Fourier transform infrared, fluorescence, and x-ray absorption spectroscopies. CO has previously been shown to be a competitive inhibitor with respect to O2, and binds to only one of the two copper atoms/active site (Blackburn, N. J., Pettingill, T. M., Seagraves, K. S., and Shigeta, R. T. (1990) J. Biol. Chem. 265, 15383-15386). Thus, it acts as an excellent probe of the O2-binding site. A single C-O infrared absorption band is observed at 2089 cm-1, shifting by 46 cm-1 to lower energy on substitution with either 13C16O or 12C18O. The 13C isotope shift is reversed to the position expected for 12CO upon vacuum flushing with 12CO gas, indicating that formation of the CO adduct is a fully reversible process. Binding of the substrate tyramine does not eliminate the infrared peak but causes a 3-cm-1 shift to lower energy. On the other hand, binding of a bifunctional inhibitor which cross-links the substrate and O2-binding site does eliminate the CO peak. These data, in conjunction with the competitive nature of CO binding with respect to O2, identify the CO-binding site as the O2-binding site, and place it in close proximity to the substrate-binding site. CO-dopamine beta-hydroxylase exhibits no luminescence in the visible region, suggesting a structure different from carbonmonoxy hemocyanin, and in all probability mononuclear. Analysis of extended x-ray absorption spectroscopy data is most consistent with an average coordination per Cu of 2-3 histidines, 0.5 CO, and 0.5 S atoms as ligands, and absorption edge comparisons indicates pseudo-4 coordination as the most likely geometry at each Cu(I) center. The results can be interpreted by a model involving inequivalent 4-coordination at each Cu(I) center in the CO adduct with CuAHis3S...CuBHis2CO-X as the coordination most consistent with all of the data. PMID:1894598

Pettingill, T M; Strange, R W; Blackburn, N J

1991-09-15

209

Admittance spectroscopy on buried GaSb junctions due to defect distribution in GaAs/GaSb metalorganic vapor phase epitaxy heterostructures  

NASA Astrophysics Data System (ADS)

Admittance spectroscopy was employed to investigate the electrical properties of buried GaSb homojunctions. A strong p-type surface layer was obtained in n-type GaSb bulk crystals through diffusion of Zn atoms. The acceptor impurities were introduced into Te-doped substrates by epitaxially growing a heavily p(Zn)-doped GaAs layer. Current-voltage investigation, after the removal of the GaAs cap layer, demonstrated the formation of the GaSb p-n homojunction. However, the p-n interface of the junctions resulted to be not due to the presence of Zn. In fact, secondary ion mass spectrometry pointed out only a small penetration depth of Zn atoms in the GaSb substrate (~100 nm), whereas electron beam induced current investigation demonstrated that the p-n junction interface was located more deeply into the substrate (~1 ?m). Admittance spectroscopy and capacitance-voltage investigations led to attribute the change of conduction type from n to p of GaSb beyond the Zn penetration depth to the formation of lattice acceptor defects, influenced by the thermal annealing processes during and after the GaAs growth. An attempt to explain the formation of the buried junction in terms of atomic inter-diffusion is provided, in order to justify, from a microscopic point of view, the low diffusivity of Zn in GaSb, and the depth of the p-n junction interface in the substrate.

Baldini, M.; Gombia, E.; Parisini, A.; Ghezzi, C.; Gorni, M.

2013-10-01

210

The isolation and characterization of growth regulatory factors produced by a herpes simplex virus Type 2 transformed mouse tumor cell line, H238  

SciTech Connect

This study was performed in an attempt to associate HSV-2-transformation with specific growth factors in order to develop a testable model for HSV-2-transformation. We report here the isolation and characterization of four growth regulatory factors produced by H238, an HSV-2-transformed mouse tumor cell line. These factors were separated from the H238-CM by heparin-sepharose affinity chromatography into three peaks of mitogenic activity and a fourth containing inhibitory activity for splenocytes. The three peaks of mitogenic activity have been identified based on physiochemical characteristics: the first supported the anchorage-independent growth of EGF treated NRK-c-49 cells and resembles transforming growth factor-{beta} (TGF-{beta}); the second bound to lectin-coated sepharose beads and was sensitive to trypsin, neuroaminidase, and the reducing agent dithiothreitol (DTT) and, resembled a platelet-derived growth factor (PDGF)-like factor; and the third displaced ({sup 125}I)-labeled basic fibroblast growth factor (bFGF) in a dose-dependent fashion when tested with a radioimmune assay. The fourth peak was inhibitory for a variety of splenocyte function assays. A model for the interaction of these factors in vivo is presented with an emphasis on testability.

Stagg, R.B.

1988-01-01

211

Characterization of human vascular smooth muscle cells transformed by the early genetic region of SV40 virus.  

PubMed Central

Human arterial smooth muscle cells transfected with the plasmid pSV3-neo, which contains the SV40 virus early region and the neor gene, developed colonies of morphologically transformed cells. Five cell strains were initiated from these colonies and could be subcultivated for up to 9 months before entering a stage of crisis that ended their life span. Deoxyribonucleic acid (DNA) molecules containing viral sequences were found free and integrated in the transformed cells. The intranuclear SV40 large T antigen and the p53 cellular protein were expressed in the transformed cells. Most of the transformed cells were spindle shaped but some were large and multinucleated. The modal chromosome numbers were in the triploid range, and aberrations, particularly dicentrics, were common. The transcripts for smooth muscle actins were significantly reduced and there were less alpha-actin filaments detected by immunofluorescence. Cytochemical staining disclosed a large accumulation of lipid droplets in the transformed cells incubated with rabbit hypercholesterolemic beta-very-low-density lipoprotein. Chemical analysis showed that cholesteryl esters were significantly elevated in these cells. Phenotypic changes induced in human vascular smooth muscle cells by SV40 early genes are similar to those found in smooth muscle cells from atherosclerotic lesions and may indicate common pathogenetic mechanisms. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Legrand, A.; Greenspan, P.; Nagpal, M. L.; Nachtigal, S. A.; Nachtigal, M.

1991-01-01

212

Characterization of the Arabidopsis Lysine-Rich Arabinogalactan-Protein AtAGP17 Mutant (rat1) That Results in a Decreased Efficiency of Agrobacterium Transformation1[w  

PubMed Central

Arabinogalactan-proteins (AGPs) are a family of complex proteoglycans widely distributed in plants. The Arabidopsis rat1 mutant, previously characterized as resistant to Agrobacterium tumefaciens root transformation, is due to a mutation in the gene for the Lys-rich AGP, AtAGP17. We show that the phenotype of rat1 correlates with down-regulation of AGP17 in the root as a result of a T-DNA insertion into the promoter of AGP17. Complementation of rat1 plants by a floral dip method with either the wild-type AGP17 gene or cDNA can restore the plant to a wild-type phenotype in several independent transformants. Based on changes in PR1 gene expression and a decrease in free salicylic acid levels upon Agrobacterium infection, we suggest mechanisms by which AGP17 allows Agrobacterium rapidly to reduce the systemic acquired resistance response during the infection process.

Gaspar, Yolanda Maria; Nam, Jaesung; Schultz, Carolyn Jane; Lee, Lan-Ying; Gilson, Paul R.; Gelvin, Stanton B.; Bacic, Antony

2004-01-01

213

Isolation and characterization of transforming growth factors from human malignant gliomas: possible role of transforming growth factors in the pathogenesis of the gliosarcoma  

SciTech Connect

This study provides the first direct experimental evidence that human malignant gliomas secrete soluble polypeptides with TGF-like activity. The conditioned medium from three well-characterized malignant glioma cell lines promote the growth of NRK indicator cells in soft agar. Following acid extraction and gel filtration, TGF-like activity was recovered from all three cell lines. Active fractions from gel filtration in two of the glioma cell lines (U-343 MG-A and SF-210) were further purified by reverse-phase HPLC. The TGF isolated from U-343 MG-A by HPLC is an acid- and heat-stable protein complex whose activity is destroyed by reducing agents and incubation with monospecific anti-TGF-alpha monoclonal antibodies. The NRK colony stimulating activity of this TGF is potentiated by the addition of TGF-beta. The partially purified U-343 MG-A TGF competes with radiolabeled (/sup 125/I)-ECF for the EGF-receptor on A431 epidermoid carcinoma cells. Finally, a total RNA preparation from U-343- MG-A contains a 4.8 kilobase mRNA for TGF-alpha. Therefore, U-343 MG-A secretes a soluble polypeptide with TGF-alpha-like activity. In contrast, the purified SF-210 malignant glioma cell line secretes an acid- and heat-stable TGF with neither TGF-alpha- nor TGF-beta-like activity.

Rutka, J.T.

1987-01-01

214

Continuous wavelet-like filter for a spherical surface and its application to localized admittance function on Mars  

Microsoft Academic Search

We have developed a 2D isotropic continuous wavelet-like transform for a spherical surface. The transform is simply defined as the surface convolution between the original field and a kernel, based on the zeroth-order Bessel function with a spherical correction. This spherical correction violates the geometric similarity for the various scales of the kernels, which becomes more apparent at longer wavelengths.

Motoyuki Kido; David A. Yuen; Alain P. Vincent

2003-01-01

215

Characterization of Nanoscale Transformations in Polyelectrolyte Multilayers Fabricated from Plasmid DNA Using Laser Scanning Confocal Microscopy in Combination with Atomic Force Microscopy  

PubMed Central

Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) were used to characterize changes in nanoscale structure that occur when ultrathin polyelectrolyte multilayers (PEMs) are incubated in aqueous media. The PEMs investigated here were fabricated by the deposition of alternating layers of plasmid DNA and a hydrolytically degradable polyamine onto a precursor film composed of alternating layers of linear poly(ethylene imine) (LPEI) and sodium poly(styrene sulfonate) (SPS). Past studies of these materials in the context of gene delivery revealed transformations from a morphology that is smooth and uniform to one characterized by the formation of nanometer-scale particulate structures. We demonstrate that in-plane registration of LSCM and AFM images acquired from the same locations of films fabricated using fluorescently labeled polyelectrolytes allows the spatial distribution of individual polyelectrolyte species to be determined relative to the locations of topographic features that form during this transformation. Our results suggest that this physical transformation leads to a morphology consisting of a relatively less disturbed portion of film composed of polyamine and DNA juxtaposed over an array of particulate structures composed predominantly of LPEI and SPS. Characterization by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) microanalysis provides additional support for this interpretation. The combination of these different microscopy techniques provides insight into the structures and dynamics of these multicomponent thin films that cannot be achieved using any one method alone, and that could prove useful for the further development of these assemblies as platforms for the surface-mediated delivery of DNA.

Fredin, Nathaniel J.; Flessner, Ryan M.; Jewell, Christopher M.; Bechler, Shane L.; Buck, Maren E.; Lynn, David M.

2010-01-01

216

Fabrication, phase transformation studies and characterization of SiC-AlN-Al2OC ceramics. Progress report.  

National Technical Information Service (NTIS)

The research effort conducted to date had two specific objectives: (1) to determine phase relations and phase transformations in SiC-AlN, AlN-Al(sub 2)OC, and SiC-Al(sub 2)OC pseudobinary systems and in SiC-AlN-Al(sub 2)OC pseudoternary system, and (2) to...

A. V. Virkar

1990-01-01

217

Experimental and theoretical characterization of the YBa2Cu3O7/YBa2Cu4O8 phase transformation.  

National Technical Information Service (NTIS)

The YBa(sub 2)Cu(sub 4)O(sub 8) to YBa(sub 2)Cu(sub 3)O(sub 7) transformation in mixed phase, superconducting YBaCuO is investigated by high resolution transmission electron microscopy and static lattice, three dimensional, Monte Carlo computer simulation...

M. Fendorf C. P. Burmester R. Gronsky L. T. Wille

1990-01-01

218

Characterization of a novel transcriptionally active domain in the transforming growth factor b-regulated Smad3 protein  

Microsoft Academic Search

Transforming growth factor b (TGFb) regulates tran- scriptional responses via activation of cytoplasmic effector proteins termed Smads. Following their phos- phorylation by the type I TGFb receptor, Smads form oligomers and translocate to the nucleus where they activate the transcription of TGFb target genes in cooperation with nuclear cofactors and coactivators. In the present study, we have undertaken a deletion

Vassiliki Prokova; Sofia Mavridou; Paraskevi Papakosta; Dimitris Kardassis

219

Characterization of Delhi iron pillar rust by X-ray diffraction, Fourier transform infrared spectroscopy and Mössbauer spectroscopy  

Microsoft Academic Search

Rust samples obtained from the region just below the decorative bell capital of the Delhi iron pillar (DIP) have been analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Mössbauer spectroscopy. The identification of iron hydrogen phosphate hydrate in the crystalline form by XRD was unambiguous. Very weak diffraction from the oxyhydroxides\\/oxides of iron was observed indicating that

R Balasubramaniam; A. V Ramesh Kumar

2000-01-01

220

Characterization of Xenorhabdus and Photorhabdus bacteria by Fourier transform mid-infrared spectroscopy with attenuated total reflection (FT-IR/ATR).  

PubMed

The use of Fourier transform mid-infrared spectroscopy with attenuated total reflection for characterizing entomopathogenic bacteria from genera Xenorhabdus and Photorhabdus is evaluated for the first time. The resulting spectra of Xenorhabdus poinarii and Photorhabdus luminiscens were compared with the spectrum of Escherichia coli samples. The absorption spectra generated by the bacteria samples, were very different at the region below 1400cm(-1) which represents the stretching vibrations of phosphate and carbohydrates. Star diagrams of the fingerprint section of nematodes spectra (between 1,350 and 1,650 cm(-1)) for separation between spectra was used and showed to be a useful tool for classification purposes. PMID:22465768

San-Blas, Ernesto; Cubillán, Néstor; Guerra, Mayamarú; Portillo, Edgar; Esteves, Iván

2012-03-13

221

Synthesis, characterization and effect of calcination temperature on phase transformation and photocatalytic activity of Cu,S-codoped TiO 2 nanoparticles  

Microsoft Academic Search

A novel copper and sulfur codoped TiO2 photocatalyst was synthesized by modified sol–gel method using titanium(IV) isopropoxide, CuCl2·2H2O and thiourea as precursors. The samples were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy equipped with energy dispersive X-ray micro-analysis (SEM-EDX), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) analysis. The XRD results showed undoped and

M. Hamadanian; A. Reisi-Vanani; A. Majedi

2010-01-01

222

Surface Wave Chirp Transform Correlator.  

National Technical Information Service (NTIS)

The feasibility of developing a surface wave chirp transform correlator (CTC) is evaluated. A comprehensive characterization of chirp transform (CT) signal processing is presented. A computer model for simulating CT processors is described, with numerous ...

H. M. Gerard O. W. Otto

1976-01-01

223

In Vitro Tn7 Mutagenesis of Haemophilus influenzae Rd and Characterization of the Role of atpA in Transformation  

Microsoft Academic Search

Haemophilus influenzae Rd is a gram-negative bacterium capable of natural DNA transformation. The compe- tent state occurs naturally in late exponential growth or can be induced by a nutritional downshift or by tran- sient anaerobiosis. The genes cya, crp, topA, and sxy (tfoX) are known to function in the regulation of competence development. The phosphoenolpyruvate:carbohydrate phosphotransferase system functions to maintain

M. L. GWINN; A. E. STELLWAGEN; N. L. CRAIG; J.-F. TOMB; H. O. SMITH

1997-01-01

224

The gas phase characterization of perfluorobutyryl chloride, C 3F 7COCl, using chirped pulse Fourier transform microwave spectroscopy  

NASA Astrophysics Data System (ADS)

A chirped pulse Fourier transform microwave spectrometer has been used to record the pure rotational spectrum of perfluorobutyryl chloride seeded in a pulsed supersonic expansion of argon gas. Only one conformer of the title molecule was observed. For the 35Cl species a total of 236 spectral transitions were recorded. Quantum chemical calculations together with the spectral constants obtained indicate that the observed conformer has the CCCCOCl centers contained within the ab plane with a dihedral angle ?CCCO = 0°.

Grubbs, G. S., II; Cooke, S. A.

2009-11-01

225

Morphometric and biochemical characterization of red beet ( Beta vulgaris L.) hairy roots obtained after single and double transformations  

Microsoft Academic Search

It is known that T-DNA of Agrobacterium rhizogenes affects processes of plant development and activates the synthesis of secondary metabolites in transformed plant cells. In\\u000a the present investigation, we provide evidence that different strains of A. rhizogenes significantly affect morphometric, morphological and functional characteristics of hairy roots of red beet (Beta vulgaris L.). Infection with four strains of A. rhizogenes

R. Thimmaraju; L. Venkatachalam; N. Bhagyalakshmi

2008-01-01

226

Initial characterizations of nontransformed and transformed (/sup 3/H )aldosterone-type I receptor complexes in brain cytosol  

SciTech Connect

Incubation of (/sup 3/H)aldosterone-type I receptor complexes in mouse brain cytosol with the chaotropic anion thiocyanate increased the fraction of receptors retained by DNA-cellulose from less than 10% to over 40%, whereas it decreased the fraction retained by protamine sulfate from more than 90% to less than 10%. Thiocyanate-induced transformation to the DNA-binding species was also accompanied by a 2.1-fold decrease in the rate of (/sup 3/H)aldosterone dissociation from type I receptors as well as by an increase in the apparent positive charge and hydrophobicity of the surface of these receptors, as revealed by DEAE Bio-Gel ion exchange and pentyl agarose hydrophobic interaction chromatography. Sucrose density gradient sedimentation and Sephacryl S-300 gel exclusion chromatography revealed a reduction in the sedimentation coefficient and Stokes radius of the steroid-receptor complex from 9.6S and 8.0 nm before to 4.7S and 6.1 nm after transformation, respectively. These changes in hydrodynamic parameters were found to correspond to a 2.8-fold reduction in the apparent molecular mass from 331,000 before to 120,000 after transformation. In view of these various findings as well as the known differential affinity of protamine sulfate for the 90K heat shock protein, we suggest that thiocyanate-induced transformation is initiated by the dissociation of two molecules of heat shock protein from each steroid/DNA-binding type I receptor subunit.

Luttge, W.G.; Rupp, M.E.; Emadian, S.M.

1989-04-01

227

Characterization of Delhi iron pillar rust by X-ray diÄraction, Fourier transform infrared spectroscopy and Mossbauer spectroscopy  

Microsoft Academic Search

Rust samples obtained from the region just below the decorative bell capital of the Delhi iron pillar (DIP) have been analyzed by X-ray diÄraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Mossbauer spectroscopy. The identification of iron hydrogen phosphate hydrate in the crystalline form by XRD was unambiguous. Very weak diÄraction from the oxyhydroxides\\/oxides of iron was observed indicating that

R. Balasubramaniam; A. V. Ramesh Kumar

228

Characterization of Growth-Differentiation Factor 15, a Transforming Growth Factor beta Superfamily Member Induced following Liver Injury  

Microsoft Academic Search

We have identified a new murine transforming growth factor b superfamily member, growth-differentiation factor 15 (Gdf15), that is expressed at highest levels in adult liver. As determined by Northern analysis, the expression of Gdf15 in liver was rapidly and dramatically up-regulated following various surgical and chemical treatments that cause acute liver injury and regeneration. In situ hybridization analysis revealed distinct

EDWARD C. HSIAO; LEONIDAS G. KONIARIS; TERESA ZIMMERS-KONIARIS; SUZANNE M. SEBALD; THANH V. HUYNH; SE-JIN LEE

2000-01-01

229

Electronic properties of the Cu2ZnSn(Se,S)4 absorber layer in solar cells as revealed by admittance spectroscopy and related methods  

NASA Astrophysics Data System (ADS)

Admittance spectra and drive-level-capacitance profiles of several high performance Cu2ZnSn(Se,S)4 (CZTSSe) solar cells with bandgap ~1.0-1.5 eV are reported. In contrast to the case for Cu(In,Ga)(S,Se)2, the CZTSSe capacitance spectra exhibit a dielectric freeze out to the geometric capacitance plateau at moderately low frequencies and intermediate temperatures (120-200 K). These spectra reveal important information regarding the bulk properties of the CZTSSe films, such as the dielectric constant and a dominant acceptor with energy level of 0.13-0.2 eV depending on the bandgap. This deep acceptor leads to a carrier freeze out effect that quenches the CZTSSe fill factor and efficiency at low temperatures.

Gunawan, Oki; Gokmen, Tayfun; Warren, Charles W.; Cohen, J. David; Todorov, Teodor K.; Barkhouse, D. Aaron R.; Bag, Santanu; Tang, Jiang; Shin, Byungha; Mitzi, David B.

2012-06-01

230

Simplified three-phase transformer model for electromagnetic transient studies  

SciTech Connect

This paper presents a simplified high-frequency model for three-phase, two- and three-winding transformers. The model is based on the classical 60-Hz equivalent circuit, extended to high frequencies by the addition of the winding capacitances and the synthesis of the frequency-dependent short-circuit branch by an RLC equivalent network. By retaining the T-form of the classical model, it is possible to separate the frequency-dependent series branch from the constant-valued shunt capacitances. Since the short-circuit branch can be synthesized by a minimum-phase-shift rational approximation, the mathematical complications of fitting mutual impedance or admittance functions are avoided and the model is guaranteed to be numerically absolutely stable. Experimental tests were performed on actual power transformers to determine the parameters of the model. EMTP simulation results are also presented.

Chimklai, S.; Marti, J.R. [Univ. of British Columbia, Vancouver, British Columbia (Canada)

1995-07-01

231

Characterization of a polypeptide present in herpes simplex virus type 2-transformed and -infected hamster embryo cells.  

PubMed Central

Transformation of hamster embryo cells by herpes simplex virus stimulated the production of a 35-kilodalton (35K) protein that was specifically immunoprecipitated, along with other polypeptides, by rabbit hyperimmune serum. This 35K polypeptide was further analyzed by partial digestion with Staphylococcus aureus V8 protease in parallel with a 35K polypeptide from herpes simplex virus type 2-infected cells. These polypeptides had almost identical partial-proteolytic cleavage maps, indicating that they are probably the same or that they are very similar polypeptides. Images

Suh, M

1982-01-01

232

Genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic Bacillus thuringiensis cryIAc gene.  

PubMed Central

Somatic embryos of jack, a Glycine max (L.) Merrill cultivar, were transformed using microprojectile bombardment with a synthetic Bacillus thuringiensis insecticidal crystal protein gene (Bt cryIAc) driven by the 35S promoter and linked to the HPH gene. Approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. The recovered lines contained the HPH gene, but the Bt gene was lost in one line. The plasmid was rearranged in the second line, and the third line had two copies, one of which was rear-ranged. The CryIAc protein accumulated up to 46 ng mg-1 extractable protein. In detached-leaf bioassays, plants with an intact copy of the Bt gene, and to a lesser extent those with the rearranged copy, were protected from damage from corn earworm (Helicoverpa zea), soybean looper (Pseudoplusia includens), tobacco budworm (Heliothis virescens), and velvetbean caterpillar (Anticarsia gemmatalis). Corn earworm produced less than 3% defoliation on transgenic plants, compared with 20% on the lepidopteran-resistant breeding line GatIR81-296, and more than 40% on susceptible cultivars. Unlike previous reports of soybean transformation using this technique, all plants were fertile. To our knowledge, this is the first report of a soybean transgenic for a highly expressed insecticidal gene.

Stewart, C N; Adang, M J; All, J N; Boerma, H R; Cardineau, G; Tucker, D; Parrott, W A

1996-01-01

233

Intelligent characterization and evaluation of yarn surface appearance using saliency map analysis, wavelet transform and fuzzy ARTMAP neural network  

Microsoft Academic Search

The evaluation of yarn surface appearance is an important routine in assessing yarn quality in textile industry. Traditionally, this evaluation is subjectively carried out by manual inspection, which is much skill-oriented, judgmental and inconsistent. To resolve the drawbacks of the manual method, an integrated intelligent characterization and evaluation model is proposed in this paper for the evaluation of yarn surface

Zhen Liang; Bingang Xu; Zheru Chi; Dagan Feng

234

Characterization and isolation of a rat liver plasma membrane NADH oxidase: Comparison to NADH oxidases from transformed cells  

Microsoft Academic Search

This work was to purify and characterize the hormone and growth factor-stimulated NADH oxidase from rat liver plasma membranes and compare it to the corresponding unregulated NADH oxidase of HeLa cell plasma membranes. Rat liver plasma membrane NADH oxidase activity was stimulated by GTP and the G protein mimicking peptide mastoparan. This activity was also stimulated by a protein fraction

James Byron Lawrence

1995-01-01

235

EBSD characterization of high-temperature phase transformations in an Al-Si coating on Cr-Mo steel  

SciTech Connect

5Cr-0.5Mo steel was coated by hot-dipping in a molten bath containing Al-10 wt.% Si. The phase transformation in the aluminide layer during diffusion at 750 Degree-Sign C in static air was analyzed by electron backscatter diffraction. The results show the aluminide layer of the as-coated specimen consisted of an outer Al-Si topcoat, a middle layer formed of scattered {tau}{sub 5(C)}-Al{sub 7}(Fe,Cr){sub 2}Si particles and minor plate-shaped {tau}{sub 4}-Al{sub 4}FeSi{sub 2} and {tau}{sub 6}-Al{sub 4}FeSi phases in the Al-Si matrix and an inner continuous {tau}{sub 5(H)}-Al{sub 7}Fe{sub 2}Si layer, respectively from the coating surface to the steel substrate. The formation of FeAl{sub 3} and Fe{sub 2}Al{sub 5} with {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} precipitates can be observed with increasing exposure time at 750 Degree-Sign C. After 5 h of exposure, the Al-Si topcoat has been consumed, and the aluminide layer consisted of Fe{sub 2}Al{sub 5} and a few {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} precipitates. The FeAl phase not only formed at the interface between Fe{sub 2}Al{sub 5} and the steel substrate, but also transformed from {tau}{sub 1}-(Al,Si){sub 5}Fe{sub 3} after diffusion for 10 h. With prolonged exposure, the aluminide layer comprised only FeAl{sub 2} and FeAl. - Highlights: Black-Right-Pointing-Pointer EBSD can differentiate phases in aluminide layer with similar chemical compositions. Black-Right-Pointing-Pointer Mapping and EBSPs functions in EBSD provide a reliable phase identification. Black-Right-Pointing-Pointer A phase transformation in the aluminide layer has been described in detail. Black-Right-Pointing-Pointer 5 Fe-Al-Si and 4 Fe-Al intermetallic phases are performed during the diffusion. Black-Right-Pointing-Pointer Cubic {tau}{sub 5(C)}-Al{sub 7} (Fe,Cr){sub 2}Si and hexagonal {tau}{sub 5(H)}-Al{sub 7}(Fe,Cr){sub 2}Si are identified.

Cheng, Wei-Jen, E-mail: d9603505@mail.ntust.edu.tw; Wang, Chaur-Jeng

2012-02-15

236

Response of Pole-Mounted Distribution Transformer to Lightning Overvoltage Dependent on Rated Capacity  

NASA Astrophysics Data System (ADS)

A pole-mounted transformer on a power distribution line is vulnerable to lightning overvoltages, and is one of the most frequently damaged instruments in Japan. Therefore, the response of transformers to the overvoltage draws great concern. By incorporating the modeling for the secondary windings proposed by Mr. Honda et al., the authors develop equivalent circuits of distribution transformers of 10kVA, 20kVA and 30kVA rated capacity based on modal analysis of measured admittance whereby one can evaluate its response to overvoltages on a low-voltage line as well as on a medium-voltage line. The validity of calculated results obtained by using the developed circuits is demonstrated by comparison with experimental results. The response of transformers made by the same manufacturer to the lightning impulse voltage waveforms is influenced by the rated capacity, and the phase and the degree of such influence is demonstrated.

Michishita, Koji; Hiraiwa, Hideo; Hongo, Yasuji

237

Suitability of the normalized difference vegetation index and the adjusted transformed soil-adjusted vegetation index for spatially characterizing loggerhead shrike habitats in North American mixed prairie  

NASA Astrophysics Data System (ADS)

Habitat loss has become one major cause of prairie loggerhead shrike population decline, which is associated with some important grassland biophysical features. However, our understanding of what and how biophysical variables can spatially characterize shrike habitats is poor. The purpose of this study is to investigate the suitability of two vegetation indices (VIs) for spatially characterizing shrike habitats in North American mixed prairies. Our research, conducted in Grasslands National Park of Canada, is based on the normalized difference vegetation index (NDVI) and the adjusted transformed soil-adjusted vegetation index (ATSAVI) as derived from both in situ measurements and SPOT imagery for three types of nesting categories at three spatial scales. Our results demonstrated that shrikes in mixed North American prairies prefer sparsely vegetated areas with a leaf area index less than 2.01 and shrub cover of around 25%. Our results also demonstrated that ATSAVI is superior to NDVI in estimating vegetation abundance and structure. Loggerhead shrikes seems to prefer habitats characterized by NDVI ranging from 0.562 to 0.616 and ATSAVI ranging from 0.319 to 0.372 with the spatial scale varying from 100 to 20 m. ATSAVI also had better performance in detecting the spatial variation of shrike habitats due to its higher sensitivity to background information.

Shen, Li; He, Yuhong; Guo, Xulin

2013-01-01

238

Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform  

USGS Publications Warehouse

Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

Maercklin, N.; Bedrosian, P. A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

2005-01-01

239

Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode. PMID:8633761

Marto, J A; White, F M; Seldomridge, S; Marshall, A G

1995-11-01

240

Isolation and characterization of human prorenin secreted from murine cells transformed with a bovine papillomavirus-preprorenin expression vector  

SciTech Connect

The authors report the construction of a plasmid-based expression vector that carries the murine metallothionein gene promoter, the human preprorenin gene, the Tn5 phosphotransferase gene, and a complete bovine papilloma virus genome. Murine cells transformed with this vector constitutively secrete high levels of human prorenin as determined by immunoprecipitation of culture media with anti-human renin antibody and activity assays. An immunoaffinity system for the isolation of human prorenin from serum-free media, or media containing serum, was developed. Purified human prorenin is stable for months and is fully activated to enzymatically mature renin by limited tryptic digestion. This is the first example of a recombinant system leading to the isolation of research quantities of highly pure and fully activatable human prorenin.

Evans, D.B.; Weighous, T.F.; Cornette, J.C.; Tarpley, W.G.; Sharma, S.K.

1987-07-01

241

Characterization of Dipalmitoylphosphatidylcholine/Cholesterol Langmuir-Blodgett Monolayers Investigated by Atomic Force Microscopy and Fourier Transform Infrared Spectroscopy  

NASA Astrophysics Data System (ADS)

The addition effects of cholesterol on the dipalmitoylphosphatidylcholine (DPPC) Langmuir-Blodgett (LB) monolayer have been investigated by atomic force microscopy (AFM) and infrared reflection absorption spectroscopy (IRRAS). The phase transformation from pure DPPC to the DPPC/cholesterol phase proceeds through two stages: initial drastic changes in the surface morphology and the conformation of the DPPC acyl chains below 10% cholesterol, and the gradual homogenization of the morphology towards the liquid-order phase up to 35% cholesterol. The IRRAS peak position indicates that the conformational disorder of the acyl chain becomes almost that of the liquid level at 10% cholesterol addition. In the homogeneous liquid-order phase at 35% cholesterol, the terminal methyl groups of the DPPC are aligned in good order similarly to the solidlike gel phase, whereas the acyl chains have a liquid-level disordered conformation.

Kim, Yong-Hoon; Tero, Ryugo; Takizawa, Morio; Urisu, Tsuneo

2004-06-01

242

Molecular characterization of transforming plasmid rearrangements in transgenic rice reveals a recombination hotspot in the CaMV 35S promoter and confirms the predominance of microhomology mediated recombination  

Microsoft Academic Search

Summary The characterization of plasmid-genomic DNA junctions following plant transformation has established links between DNA double-strand break repair (DSBR), illegit- imate recombination and plasmid DNA integration. The limited information on plasmid-plasmid junctions in plants comes from the dicot species tobacco and Arabidopsis .W e analyzed 12 representative transgenic rice lines, carrying a range of transforming plasmid rearrangements, which predominantly reflected

Ajay Kohli; Simon Griffiths; Natalia Palacios; Richard M. Twyman; Philippe Vain; David A. Laurie; Paul Christou

1999-01-01

243

Elemental and spectroscopic methods with chemometric analysis for characterizing composition and transformation of dissolved organic matter during chicken manure composting.  

PubMed

Dissolved organic matter was extracted from chicken manure after 1, 8, 16, 28 and 40 days of composting and characterized by combining elemental and spectroscopic methods with chemometric analysis to investigate the evolution of composting materials. The elemental and spectroscopic analysis results showed that the composting process was characterized by the biodegradation of aliphatics, polysaccharide and proteins, as well as by the synthesis of aromatic structures, humic-like substances and macromolecules. Principal component analysis and correlation analysis indicated that the data from elemental and spectroscopic analysis fell into three main groups, and corresponded to the biodegradation, aromatization, and humification and polymerization state of the composting materials. Hierarchical cluster analysis indicated rapid biodegradation of organic matter during the first eight days, and the formation of aromatic structures, humic-like materials and macromolecules in dissolved organic matter after eight days. PMID:23240197

He, Xiao-Song; Xi, Bei-Dou; Jiang, Yong-Hai; Li, Ming-Xiao; Yu, Hui-Bin; An, Da; Yang, Yu; Liu, Hong-Liang

2012-09-01

244

Microheterogeneity of human saliva peptide PC characterized by high-resolution top-down fourier-transform mass spectrometry  

Microsoft Academic Search

Top-down proteomics characterizes protein primary structures with unprejudiced descriptions of expressed and processed gene\\u000a products. Gene sequence polymorphisms, protein post-translational modifications, and gene sequence errors can all be identified\\u000a using top-down proteomics. Saliva offers advantages for proteomic research because of availability and the noninvasiveness\\u000a of collection and, for these reasons, is being used to search for disease biomarkers. The description

Frédéric Halgand; Vlad Zabrouskov; Sara Bassilian; Puneet Souda; David T. Wong; Joseph A. Loo; Kym F. Faull; Julian P. Whitelegge

2010-01-01

245

Incomplete nuclear transformation of human spermatozoa in oligo-astheno-teratospermia: characterization by indirect immunofluorescence of chromatin and thiol status  

Microsoft Academic Search

BACKGROUND Sperm heterogeneity in the human, as observed in oligo-astheno-teratozoospermia (OAT), is associated with hypospermatogenesis. METHODS The chromatin of sperm from OAT and normospermic males was characterized with antibodies specific for nucleosomes, the histone H3.1\\/H3.2 isoform, histone TH2B, apoptosis-associated H4 acetylation (KM-2) and protamines. Subsequently, sperm samples were stained with the thiol-specific fluorochrome monobromobimane (mBBr) before and after reduction with

L. Ramos; G. W. van der Heijden; A. Derijck; J. H. M. Berden; J. A. M. Kremer; J. van der Vlag; P. de Boer

2008-01-01

246

Characterization of neutral oligosaccharide-alditols from Xenopus laevis egg jelly coats by matrix-assisted laser desorption Fourier transform mass spectrometry.  

PubMed

Neutral oligosaccharides were released by alkaline sodium borohydride reduction of the jelly coating from the South African clawed toad, Xenopus laevis. The oligosaccharides were isolated by HPLC and analyzed by matrix-assisted laser desorption ionization (MALDI)-Fourier transform mass spectrometry (FTMS). The mass spectrometry analysis allowed confirmation of 12 structures first proposed by Strecker et al. using nuclear magnetic resonance. In addition, seven new oligosaccharides with weak abundances were found and characterized by mass spectrometry. A method for discriminating metastable fragments from quasimolecular ions is described. It involves doping the sample with cesium chloride. Cesium-coordinated oligosaccharides do not fragment as readily as those coordinated to sodium. Tandem MS experiments are performed on an unknown oligosaccharide illustrating the potential of MALDI-collision-induced dissociation-FTMS. PMID:9234894

Tseng, K; Lindsay, L L; Penn, S; Hedrick, J L; Lebrilla, C B

1997-07-15

247

Biochemical characterization of the Drosophila dpp protein, a member of the transforming growth factor beta family of growth factors.  

PubMed Central

The decapentaplegic (dpp) gene of Drosophila melanogaster is required for pattern formation in the embryo and for viability of the epithelial cells in the imaginal disks. The dpp protein product predicted from the DNA sequence is similar to members of a family of growth factors that includes transforming growth factor beta (TGF-beta). We have produced polyclonal antibodies to a recombinant dpp protein made in bacteria and used a metallothionein promoter to express a dpp cDNA in Drosophila S2 cells. Similar to other proteins in the TGF-beta family, the dpp protein produced by the Drosophila cells was proteolytically cleaved, and both portions of the protein were secreted from the cells. The amino-terminal 47-kilodalton (kDa) peptide was found in the medium and in the proteins adhering to the plastic petri dish. The carboxy-terminal peptide, the region with sequence similarity to the active ligand portion of TGF-beta, was found extracellularly as a 30-kDa homodimer. Most of the 30-kDa homodimer was in the S2 cell protein adsorbed onto the surface of the plastic dish. The dpp protein could be released into solution by increased salt concentration and nonionic detergent. Under these conditions, the amino-terminal and carboxy-terminal portions of dpp were not associated in a stable complex. Images

Panganiban, G E; Rashka, K E; Neitzel, M D; Hoffmann, F M

1990-01-01

248

Improving brain tumor characterization on MRI by probabilistic neural networks and non-linear transformation of textural features.  

PubMed

The aim of the present study was to design, implement and evaluate a software system for discriminating between metastatic and primary brain tumors (gliomas and meningiomas) on MRI, employing textural features from routinely taken T1 post-contrast images. The proposed classifier is a modified probabilistic neural network (PNN), incorporating a non-linear least squares features transformation (LSFT) into the PNN classifier. Thirty-six textural features were extracted from each one of 67 T1-weighted post-contrast MR images (21 metastases, 19 meningiomas and 27 gliomas). LSFT enhanced the performance of the PNN, achieving classification accuracies of 95.24% for discriminating between metastatic and primary tumors and 93.48% for distinguishing gliomas from meningiomas. To improve the generalization of the proposed classification system, the external cross-validation method was also used, resulting in 71.43% and 81.25% accuracies in distinguishing metastatic from primary tumors and gliomas from meningiomas, respectively. LSFT improved PNN performance, increased class separability and resulted in dimensionality reduction. PMID:18053610

Georgiadis, Pantelis; Cavouras, Dionisis; Kalatzis, Ioannis; Daskalakis, Antonis; Kagadis, George C; Sifaki, Koralia; Malamas, Menelaos; Nikiforidis, George; Solomou, Ekaterini

2007-11-28

249

Synthesis, structural and spectroscopic characterization, catalytic properties, and thermal transformations of new cyclic di- and trisiloxanediolato tantalum complexes.  

PubMed

The reaction between Ta(OEt)5 and 1,1,3,3-tetramethyl-1,3-disiloxanediol, (HOSiMe2OSiMe2OH), leads to new siloxy complexes in which the dimeric nature of Ta(OEt)5 is maintained with both bridging ethoxide and disiloxanediolato bridges. With equal amounts of the reagents, two terminal OEt groups are replaced to form [Ta(OEt)2]2(mu-OEt)2(mu-OSiMe2OSiMe2O)2, 1, whereas with an excess of diol, the remaining terminal OEt groups are also replaced but with a trisiloxanediolato unit to form [Ta(OSiMe2OSiMe2OSiMe2O)]2(mu-OEt)2(mu-OSiMe2OSiMe2O)2, 2. Complexes 1 and 2 catalyze the transformation of HOSiMe2OSiMe2OH to polysiloxanes. Thermal treatment of 1 results in the formation of a 1:2 mixture of Ta2O5/SiO2; no new phases are observed. The molecular structures of 1 and 2 are confirmed by X-ray crystallography. PMID:16499384

Kapoor, Ramesh N; Cervantes-Lee, Francisco; Campana, Charles F; Haltiwanger, Curtis; Abney, Kent; Pannell, Keith H

2006-03-01

250

Characterization of a new melanocyte-specific gene (QNR-71) expressed in v-myc-transformed quail neuroretina.  

PubMed Central

Quail neuroretina cells (QNR) infected with the v-myc-expressing retrovirus MC29 become pigmented after several passages in vitro. After differential screening of a cDNA library constructed from these cells, we have isolated a cDNA clone (QNR-71) which identifies an RNA expressed only in the pigmented layer of the retina and in the epidermis. This gene can also be induced in other cell types transformed by MC29, suggesting that QNR-71 may be regulated by the v-myc protein. Sequence analysis showed that the QNR-71 cDNA exhibits stretches of homologies with melanosomal proteins encoding genes. From bacterially expressed QNR-71 peptides we obtained rabbit antisera able to specifically recognize two proteins of 95 and 100 kDa in pigmented retinal cells, but not in the neuroretina. To study the regulation of QNR-71, we used promoter fragments linked to the CAT reporter gene, in transient co-expression assay. We observed an increase in CAT expression with a c-MYC and microphtalmia (mi) expression vectors. Both MYC and mi activate the QNR-71 promoter through direct binding to a CATGTG site present in the promoter fragment. Images

Turque, N; Denhez, F; Martin, P; Planque, N; Bailly, M; Begue, A; Stehelin, D; Saule, S

1996-01-01

251

Characterization of copper surfaces used in electronic circuit boards by reflectance FT-IR[Fouier Transform - Infrared  

SciTech Connect

Organic and organo-metallic coatings are presently being applied over bare copper as an approach to improve the co-planarity of circuit boards. Conformal organic solderability preservative coatings (OSP) are environmentally and economically advantageous over the more commonly used lead based coatings. Problems arise in assessing the solderability of the bare copper and the integrity of the organic coating. Specular reflectance Fourier transform infrared spectroscopy (FT-IR) was utilized to monitor and evaluate the formation of Cu oxides occurring on copper substrates used in the manufacturing of electronic circuit boards. Previous studies reported the utility of this technique. By measuring the oxide and protective coating characteristics of these surfaces, their solderability performance can rapidly be evaluated in a manufacturing environment. OSP coated test specimens were subjected to hot-dry and hot-wet environmental conditions using MIL-STD-202F and MIL-STD-883E as guides. The resultant FT-IR spectra provided clear evidence for the formation of various Cu oxides at the Cu/OSP interface over exposure time, for the samples subjected to the hot-dry environment. IR spectral bands consistent with O-Cu-O and Cu{sub 2}O{sub 2} formation appear, while very minimal deterioration to the OSP coating was observed. The appearance of the Cu oxide layers grew steadily with increased environmental exposure. Specimens subjected to the hot-wet conditions showed no significant signs of deterioration. The IR data can be directly correlated to solderability performance as evaluated by wet balance testing.

Sloan, J.M.; Pergantis, C.G.

2000-07-01

252

Preparation and in situ Characterization of Surfaces Using Soft-Landing in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer  

SciTech Connect

Mass-selected peptide ions produced by electrospray ionization were deposited onto fluorinated self-assembled monolayer surfaces (FSAM) surfaces by soft-landing using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially designed for studying interactions of large ions with surfaces. Analysis of the modified surface was performed in situ by combining 2 keV Cs+ secondary ion mass spectrometry with FT-ICR detection of the sputtered ions (FT-ICR-SIMS). Regardless of the initial charge state of the precursor ion, the SIMS mass spectra included singly-protonated peptide fragment ions and peaks characteristic of the surfaces in all cases. In some experiments multiply-protonated peptide ions and [M+Au]+ ions were also observed upon SIMS analysis of modified surfaces. For comparison with the in situ analysis of the modified surfaces, ex situ analysis of some of the modified surfaces was performed by 25 kV Ga+ time of flight ? secondary ion mass spectrometry (ToF-SIMS). The ex situ analysis demonstrated that a significant number of soft-landed peptide ions remain charged on the surface even when exposed to air for several hours after deposition. Charge retention of soft-landed ions dramatically increases the ion yields obtained during SIMS analysis very sensitive detection of deposited material at less than 1% of monolayer coverage. Accumulation of charged species on the surface undergoes saturation due to Coulomb repulsion between charges at close to 30% coverage. We estimated that close to 1 ng of peptide could be deposited on the spot area of 4 mm2 of the FSAM surface without reaching saturation.

Alvarez, Jormarie; Cooks, Robert G.; Barlow, Stephan E.; Gaspar, Dan J.; Futrell, Jean H.; Laskin, Julia

2005-06-01

253

Isolation and characterization of water-soluble intermediates of blue pigments transformed from geniposide of Gardenia jasminoides.  

PubMed

Gardenia blue dye was obtained through the reaction of methylamine with genipin, the aglycone of geniposide isolated from the fruits of Gardenia jasminoides. The resulting blue pigments were passed through Bio-Gel P-2 resin yielding five fractions, GM1-GM5. Four fractions (GM1-GM4) were all blue pigments, and the first eluted higher molecular weight fraction GM1 had a higher tinctorial strength than the later eluted lower molecular weight fractions, GM2-GM4. The last eluted GM5 fraction with lambda(max) of 292 nm was colorless and was confirmed as the true intermediate of the blue pigments on the basis of UV-vis spectrophotometric evidence. The GM5 fraction was composed of two epimeric isomers, and their structures were characterized by (1)H NMR, (1)H-(1)H COSY, (13)C NMR, and HMQC and HMBC spectral measurements. PMID:12381142

Park, Jee-Eun; Lee, Jae-Youn; Kim, Hong-Gyu; Hahn, Tae-Ryong; Paik, Young-Sook

2002-10-23

254

Molecular characterization of monoterpene ozonolysis products using ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry  

NASA Astrophysics Data System (ADS)

A detailed knowledge of the chemical composition of secondary organic aerosols (SOA) is required to better understand their roles in climate change, biogeochemical cycling and public health. The chemical composition of the SOA produced by the ozonolysis of limonene was investigated using electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry. SOA was generated in a 1.5 m3 teflon chamber with 500 ppb of limonene and 250 ppb of O3, without the presence of hydroxyl radical scavenger. We have identified approximately 1300-1500 molecular masses from negative-ion spectra in the range of 105 < m/z < 870 in each of two samples. The double bond equivalency (DBE), the number of rings and unsaturated bonds, values range from 1 to 13. This indicates the formation of a wide variety of chemical compounds. Several regions of high peak number density were observed in the mass ranges of 170 < m/z < 280, 350 < m/z < 480, 550 < m/z < 650 and 730 < m/z < 850. These regions are generally referred to as monomers, dimers, trimers, and tetramers of oxidized monoterpene units. The average DBE values for monomer to tetramer regions increase from 3.7 to 9.4 and the oxidation number decreases from -0.4 to -0.7. These results suggest that high MW organic compounds in the SOA samples are more unsaturated and less-oxidized. Both the oxygen to carbon (0.2-2) and hydrogen to carbon (0.5-1.1) ratios for limonene-SOA are different from those for ?-pinene-SOA, 0.2-1 and 1.1-1.9 (Putman et al., 2010). We will compare the chemical composition of limonene-SOA with that of ?- and ?-pinene-SOA. We will also discuss the MSn fragmentation behavior of major ions for the structural elucidation of the oligomers. Putman, A., J. Offenberg, R. Fisseha, T. Rahn, and L. R. Mazzoleni, Ultrahigh-resolution mass spectrometry of the complex secondary organic aerosol products from ozonolysis of ?-pinene: Investigating oligomers, in preparation, 2010.

Kundu, S.; Fisseha, R.; Putman, A.; Rahn, T.; Mazzoleni, L. R.

2010-12-01

255

Ear-canal acoustic admittance and reflectance measurements in human neonates. II. Predictions of middle-ear dysfunction and sensorineural hearing loss  

NASA Astrophysics Data System (ADS)

This report describes relationships between middle-ear measurements of acoustic admittance and energy reflectance (YR) and measurements of hearing status using visual reinforcement audiometry in a neonatal hearing-screening population. Analyses were performed on 2638 ears in which combined measurements were obtained [Norton et al., Ear Hear. 21, 348-356 (2000)]. The measurements included distortion-product otoacoustic emissions (DPOAE), transient evoked otoacoustic emissions (TEOAE), and auditory brainstem responses (ABR). Models to predict hearing status using DPOAEs, TEOAEs, or ABRs were each improved by the addition of the YR factors as interactions, in which factors were calculated using factor loadings from Keefe et al. [J. Acoust. Soc. Am. 113, 389-406 (2003)]. This result suggests that information on middle-ear status improves the ability to predict hearing status. The YR factors were used to construct a middle-ear dysfunction test on 1027 normal-hearing ears in which DPOAE and TEOAE responses were either both present or both absent, the latter condition being viewed as indicative of middle-ear dysfunction. The middle-ear dysfunction test classified these ears with a nonparametric area (A) under the relative operating characteristic curve of A=0.86, and classified normal-hearing ears that failed two-stage hearing-screening tests with areas A=0.84 for DPOAE/ABR, and A=0.81 for TEOAE/ABR tests. The middle-ear dysfunction test adequately generalized to a new sample population (A=0.82).

Keefe, Douglas H.; Gorga, Michael P.; Neely, Stephen T.; Zhao, Fei; Vohr, Betty R.

2003-01-01

256

Separate measurement of the density and viscosity of a liquid using a quartz crystal microbalance based on admittance analysis (QCM-A)  

NASA Astrophysics Data System (ADS)

We previously used a quartz crystal microbalance (QCM) to identify a frequency f2 that allows measurement of the mass load without being affected by the viscous load of a liquid in the liquid phase. Here, we determined that frequency in order to separately measure the density and viscosity of a Newtonian liquid. Martin et al separately measured the density and viscosity of a liquid by immersing two quartz resonators, i.e. a smooth-surface resonator and a textured-surface resonator, in the liquid. We used a QCM based on admittance analysis (QCM-A) in the current study to separately measure the viscosity and density of a liquid using only a textured-surface resonator. In the current experiments, we measured the density and viscosity of 500 µl of 10%, 30%, and 50% aqueous glycerol solutions and compared the measured values to reference values. The density obtained had an error of ±1.5% of reference values and the viscosity had an error of about ±5% of reference values. Similar results were obtained with 500 µl of 10%, 30%, and 50% ethanol solutions. Measurement was possible with a quartz resonator, so measurements were made with even smaller samples. The density and viscosity of a liquid were successfully determined with an extremely small amount of liquid, i.e. 10 µl, with almost the same precision as when using 500 µl of the liquid.

Itoh, Atsushi; Ichihashi, Motoko

2011-01-01

257

Characterization of the primary electron donor of photosystem I, P700, by electrochemistry and Fourier transform infrared (FTIR) difference spectroscopy  

NASA Astrophysics Data System (ADS)

The redox reactions of P700, the primary electron donor of photosystem I (PS I), have been analyzed by electrochemistry and Fourier transform infrared (FTIR) spectroscopy in two different preparations from the cyanobacterium Synechocystis PCC 6803 yielding monomeric and trimeric PS I complexes, respectively. Reversible and quantitative oxidation and rereduction of P700 has been achieved at surface-modified electrodes in an optically and infrared transparent thin-layer electrochemical (OTTLE) cell. The midpoint potential ( Em = +260 ± 10 mV vs. Ag/AgCl/3 M KCl) determined from these titrations, either by monitoring the electrochemically-induced oxidation/reduction of the primary electron donor P700 at 700 nm or by monitoring the amplitude of the flash-induced absorbance change at 707 nm as a function of the applied potential, agree between monomeric and trimeric PS I, demonstrating that protein-protein contact has very little impact on the redox properties of P700. Using electrochemical oxidation and rereduction, the vibrational IR difference spectra P700 ·+ - P700 could be generated. In the 1800-1200 cm -1 spectral region, highly structured IR difference spectra were obtained. The IR difference bands titrate in unison and are fully reversible upon application of a reducing potential. The midpoint potential measured by titration of the absorbance difference of two prominent bands, at 1714 and 1696 cm -1( Em = +260 ± 10 mV) corresponds to the values determined by titration of the electronic transition of P700. In contrast to previously obtained FTIR difference spectra for light-induced charge separation (E. Nabedryk, M. Leonhard, W. Mäntele and J. Breton, Biochemistry, 29 (1990) 3242; G. MacDonald, K.A. Bixby and B.A. Barry, Proc. Natl. Acad. Sci. USA, 90 (1993) 11024) which include contributions from the primary electron donor and the acceptor side, the electrochemical generated FTIR difference spectra exclusively reflect the molecular changes at P700 and its protein site upon removal of an electron. Nevertheless, they largely agree with the difference spectra of the charge-separated state. In the 1800-1680 cm -1 range, the IR difference signals are attributed to the keto and ester C=O modes of P700. Between 1700 and 1680 cm -1, shifts of bands and changes of band intensities for photosystem I particles suspended in 2H 2O reveal contributions of amide I modes. Further effects of 2H 2O/ 1H 2O exchange are observed between 1600 and 1500 cm -1, and around 1400 cm -1. Between 1750 cm -1 and approximately 3000 cm -1, no FTIR difference signals were detected. In particular, no broad but strong absorbance changes were detected around 2600 cm -1, where a low-energy electronic transition, characteristic for the dimeric nature of P and P +, was detected for P865 in bacterial reaction centers (J. Breton, E. Nabedryk and W. Parson, Biochemistry, 31 (1992) 7503). This indicates that the positive charge on P700 ·+ is rather localized on one of the chlorophylls.

Hamacher, E.; Kruip, J.; Rögner, M.; Mäntele, W.

1996-01-01

258

Characterization and petrophysical properties of hydrothemally altered lacustrine volcanistic rock in Geyser Valley (Kamchatka) and its transformation by weathering  

NASA Astrophysics Data System (ADS)

Work is devoted to the study of volcano sedimentary hydrothermally altered rocks in Geyser Valley (Kamchatka peninsula, Russia). The Geyser Valley is one of the most unique nature objects in Russia. There are quite large geyser fields. The valley of the river is part of the Uson-Geysernaya depression, where hydrothermal activity is very high. Besides geysers here are hot springs, mud pots and fumarols. In the late Pleistocene (about 45-35 thousand years ago) the lake was located in the site of the modern valley of the Geysernaya river, where sediments accumulated intensively. Sedimentary material came from several sources in the form of pyroclastic flows, ash falls, was supplied by permanent and temporary water streams. The total deposit thickness reached several hundred meters. In the late Pleistocene there was breakthrough of reservoir and further conditions for the lacustrine deposits formation did not arose. Later the rocks were intensively processed by thermal water. In 2007 large landslide was formed in lower part of the Geysernaya River on their left slope. Deposits of Geysernaya (Q34grn) series and Pemsovaya (Q34pmz) series were involved in landslide displacement. The headscarp was formed up to 100 m and a length of 800 m, exposing the volcano-sedimentary section of hydrothermally altered rocks - a unique opportunity for sampling and subsequent laboratory study. Thickness of lake sediments is interbedding of coarse-grain, medium-grain, fine-grain tuffites predominantly acidic composition. The study of thin sections revealed that all samples are lithoclastic and vitroclastic hydrothermally altered tuffits. Currently, the primary minerals and volcanic glass is largely replaced by clay minerals of the smectite group. Pores and cracks are made zeolites (heulandite and clinoptilolite). All this points to the low-temperature (<200 ° C) hydrothermal conditions with a pH near neutral. Tyere are acid plagioclase and quartz in most samples The high content of smectite causes high hygroscopy of deposits. Rocks are highly porous - of 37-65%, primarily low density - 0,9-1,65 g/cm3 wave velocities - from 0.74 km/s for porous to 3.42 km/sec for dense varieties. All samples are characterized by low strength characteristics: uniaxial compressive strength - 1.2 - 21.7 MPa, uniaxial tension - 0,6-4,7 MPa. By water saturation strength decreases rapidly. Soft coefficient ranges from 0.22 to 0.57. Proving to be on the land surface as a result of slope deformation, volcanic-sedimentary hydrothermally altered rocks are destroyed quickly by precipitation and temperature fluctuations Rock turned to sand, silt and clay depending on the original composition. It was found that often weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased content of clay minerals (to 90%), decreasing the content of zeolites (not to exceed 10%). Quartz and plagioclase form sans fraction. Physical and mechanical properties vary widely: the density of the soil increases slightly up to 1,57-1,59 g/cm3 for sands, 1,2-1,79 g/cm3 for clays, porosity of 51-52% and 49-78% respectively, moisture 22-23% and 43-98/ Clays are in a state of semi-solid to fluid. The high content of smectite determines high plastic properties. Plasticity Index varies widely from 11 to 57. Cohesion and the internal friction angle obtained from shear tests also change widely. For clayey sand grip reaches 137 kPa, internal friction angle - 17 degrees. In clay grip ranges from 13 kPa to 120 kPa, and the internal friction angle - from 11 degrees to 31 degrees. Large variation of properties of the investigated soils is explained by the inhomogeneity of volcano-sedimentary formations both vertically and laterally, varying degrees of hydrothermal alteration and of weathering, fracturing and cracks filling The obtained datas can adequately characterize the volcanic-lacustrine sediments in the valley of the Geysernaya river and use them in calculations of slope stability and for and geological mapping.

Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

2013-04-01

259

Effect of aging on the spectral response of transformer oil  

Microsoft Academic Search

Recent studies have characterized the response of the absorption of transformer oil to in-service and laboratory aged transformer oils. The results, established using a laboratory grade spectrophotometer, indicate that both for transformer oil degraded in the laboratory and for transformer oil drawn from transformers that have been in service for extended periods of time, the transformer oil absorbance increases by

John A. Palmer; Xianghui Wang; R. A. Shoureshi; A. Mander; Duane Torgerson; Charles Rich

2000-01-01

260

ThyroScreen system: high resolution ultrasound thyroid image characterization into benign and malignant classes using novel combination of texture and discrete wavelet transform.  

PubMed

Using right equipment and well trained personnel, ultrasound of the neck can detect a large number of non-palpable thyroid nodules. However, this technique often suffers from subjective interpretations and poor accuracy in the differential diagnosis of malignant and benign thyroid lesions. Therefore, we developed an automated identification system based on knowledge representation techniques for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (10 benign and 10 malignant), taken from 3-D high resolution ultrasound (HRUS) images were used for this work. Malignancy was confirmed using fine needle aspiration biopsy and subsequent histological studies. A combination of discrete wavelet transformation (DWT) and texture algorithms were used to extract relevant features from the thyroid images. These features were fed to different configurations of AdaBoost classifier. The performance of these configurations was compared using receiver operating characteristic (ROC) curves. Our results show that the combination of texture features and DWT features presented an accuracy value higher than that reported in the literature. Among the different classifier setups, the perceptron based AdaBoost yielded very good result and the area under the ROC curve was 1 and classification accuracy, sensitivity and specificity were 100%. Finally, we have composed an Integrated Index called thyroid malignancy index (TMI) made up of these DWT and texture features, to facilitate distinguishing and diagnosing benign or malignant nodules using just one index or number. This index would help the clinicians in more quantitative assessment of the thyroid nodules. PMID:22054816

Acharya, U Rajendra; Faust, Oliver; Sree, S Vinitha; Molinari, Filippo; Suri, Jasjit S

2011-11-04

261

Characterization of glyceraldehyde-3-phosphate dehydrogenase gene RtGPD1 and development of genetic transformation method by dominant selection in oleaginous yeast Rhodosporidium toruloides.  

PubMed

The oleaginous yeast Rhodosporidium toruloides, which belongs to the Pucciniomycotina subphylum in the Basidiomycota, has attracted strong interest in the biofuel community recently due to its ability to accumulate more than 60% of dry biomass as lipid under high-density fermentation. A 3,543-nucleotide (nt) DNA fragment of the glyceraldehyde-3-phosphate dehydrogenase gene (GPD1) was isolated from R. toruloides ATCC 10657 and characterized in details. The 1,038-nt mRNA derived from seven exons encodes an open reading frame (ORF) of 345 amino acids that shows high identity (80%) to the Ustilago maydis homolog. Notably, the ORF is composed of codons strongly biased towards cytosine at the Wobble position. GPD1 is transcriptionally regulated by temperature shock, osmotic stress, and carbon source. Nested deletion analysis of the GPD1 promoter by GFP reporter assay revealed that two regions, -975 to -1,270 and -1,270 to -1,429, upstream from the translational start site of GPD1 were important for responses to various stress stimuli. Interestingly, a 176-bp short fragment maintained 42.2% promoter activity of the 795-bp version in U. maydis whereas it was reduced to 17.4% in R. toruloides. The GPD1 promoter drove strong expression of a codon-optimized enhanced green fluorescent protein gene (RtGFP) and a codon-optimized hygromycin phosphotransferase gene (hpt-3), which was critical for Agrobacterium tumefaciens-mediated transformation in R. toruloides. PMID:22722909

Liu, Yanbin; Koh, Chong Mei John; Sun, Longhua; Hlaing, Mya Myintzu; Du, Minge; Peng, Ni; Ji, Lianghui

2012-06-22

262

Isolation and characterization of a siderophore-like growth factor from mutants of SV40-transformed cells adapted to picolinic acid.  

PubMed

We have isolated mutants of SV40-transformed BALB/3T3 cells adapted to grow in picolinic acid. A line of cells, derived from the mutant cells, that multiplies in the absence of serum has also been characterized. From ultrafiltrates of medium conditioned by contact with these cell lines, we have identified and partially purified a highly specific iron-binding ligand termed siderophore-like growth factor (SGF). Experiments have indicated that the factor is a peptide(s) of approximately 1600 daltons. In nanogram amounts, SGF solubilizes and binds Fe 3+ in vitro and stimulates the uptake of Fe 3+ in vivo. The Fe 3+ uptake preceded the stimulation of DNA synthesis induced by the factor in the mutant cell lines. The factor could not be separated into Fe 3+ binding and DNA synthetic activity, suggesting that the early iron uptake is an integral component of the proliferative response. These data support the hypothesis that SGF is representative of a family of mammalian siderophores which may have an important role in cell proliferation. PMID:210954

Fernandez-Pol, J A

1978-07-01

263

Dielectric relaxation in hafnium oxide: A study of transient currents and admittance spectroscopy in HfO2 metal-insulator-metal devices  

NASA Astrophysics Data System (ADS)

Dielectric relaxation is studied in 10 nm HfO2 thin films which are deposited by atomic layer deposition on TiN and Pt electrodes. Transient currents are recorded from 10-3 s to 10 s, as a function of bias (0.1 V to 1 V) and temperature (20 °C to 180 °C). A Curie-von Schweidler law is observed, I = Q0/t?. The power law exponent ? is constant with bias and strongly depends on the temperature (varying in the 0.65-1.05 range, with a peak at 75 °C). The amplitude Q0 is described by a relation of the form Q0 = C0V?, where the factor C0 is weakly activated and the exponent ? varies with temperature (in the 0.9-1.5 range as T varies). Transient currents are discussed along with tunneling based models from the literature. To complement transient current experiments, admittance spectroscopy (conductance G and capacitance C) is performed at low frequencies, from 0.01 Hz to 10 kHz. The dispersion law of the conductance is of the form G ~ ?s. The capacitance is the sum of two terms, a non-dispersive term (C?) and a low-frequency dispersive term, CLF ~ ?-n. The critical exponents s and n verify s ~ ? and n ~ 1-?. At room temperature, the dielectric constant is expressed as ?' = ?\\eh' f-n + \\eh'?, where \\eh'? = 11.1, n ~ 0.2/0.3 (Pt/TiN), and ?\\eh' ~ 1.5/0.7 (Pt/TiN).

Mannequin, C.; Gonon, P.; Vallée, C.; Bsiesy, A.; Grampeix, H.; Jousseaume, V.

2011-11-01

264

Isostatic response of the Alula-Fartak and Owen transforms in the Eastern Gulf of Aden and the adjoining Arabian Sea  

NASA Astrophysics Data System (ADS)

The Alula-Fartak and Owen transforms are the active parts of major fracture zones with a distinct topographic expression in the Eastern Gulf of Aden and the Arabian Sea, respectively. While the Alula-Fartak transform offsets the Sheba Ridge by about 180 km and is associated with a broad steep-sided valley with a relief of nearly 3.5 km, the Owen transform offsets the Carlsberg Ridge by nearly 300 km and is associated with a broad step-like valley surrounded by deeper water depths. The gravity and topography data along several profiles selected across these two transforms have been analysed using cross-spectral analysis in order to investigate their isostatic compensation. The observed admittance estimates have been compared with three theoretical isostatic compensation models, two local compensation models (Airy I and II) and one regional compensation (plate) model. Comparing the longer wavelength admittance estimates suggests that the regional compensation model gives the best fit for both the Alula-Fartak transform and the Owen transform, with effective elastic thickness (Te) of 5 km and slightly less than 10 km, respectively. For the Alula-Fartak transform, the Airy II model might also be acceptable, though with large scatter in the observed values: it suggests a mean value of 9 km for the mantle layer with a 6 km thick crust. For the Owen transform, on the other hand, the two local compensation models failed. The difference in Te estimate between the two transforms could be ascribed to differences in thermal structure arising from their varied tectonic history. A comparison with the isostatic response estimates of transform/fracture zones along the slow-spreading Mid-Atlantic Ridge suggests that the regional compensation model is generally applicable for transform/fracture zone topography along such mid-ocean ridges.

Radhakrishna, M.; Searle, R. C.

2006-04-01

265

Molecular cloning and characterization of two tropinone reductases in Anisodus acutangulus and enhancement of tropane alkaloid production in AaTRI-transformed hairy roots.  

PubMed

Tropane alkaloids are used medicinally as anticholinergic agents with increasing market demand, so the improvement and production of active components from medicinal plants using molecular biotechnology show great potential for applications that should benefit human healthcare. Two tropinone reductases constitute a branching point in the biosynthesis of tropane alkaloids. In the present paper, we report for the first time the cloning and characterization of two fulllength cDNAs encoding TRI (tropinone reductase I) (GenBank accession number EU424321) and TRII (tropinone reductase II) (GenBank(R) accession number EU424322) from the solanaceous plant Anisodus acutangulus by rapid amplification of cDNA ends. Sequence comparison indicated that AaTRI (A. acutangulus TRI) and AaTRII (A. acutangulus TRII) had high homology with other tropinone reductases from Hyoscyamus niger, Datura stramonium etc., but AaTRI and AaTRII showed identity of only 60.8%. Phylogenetic-tree analysis showed that AaTRI and AaTRII belong to different clusters and have the closest relationship with H. niger TRI and TRII respectively. Expression-pattern analysis showed that AaTRI and AaTRII were expressed in all tissues tested, including root, stem and leaf, but the transcript level of AaTRI was much lower than AaTRII. Expression of AaTRI and AaTRII could be enhanced by methyl jasmonate, with a weak effect for AaTRI and a strong effect for AaTRII. AaTRI-transformed hairy-root lines were accompanied by a mean 1.87-fold higher level of hyoscyamine and a mean 8-fold higher level of scopolamine compared with control roots, indicating that AaTRI is a promising target for genetic engineering to increase tropane alkaloid in A. acutangulus. PMID:19751215

Kai, Guoyin; Li, Li; Jiang, Yuxin; Yan, Xiangming; Zhang, Yan; Lu, Xuan; Liao, Pan; Chen, Jianbo

2009-10-23

266

Phenotypic Characterization of Shewanella oneidensis MR-1 under Aerobic and Anaerobic Growth Conditions by Using Fourier Transform Infrared Spectroscopy and High-Performance Liquid Chromatography Analyses?  

PubMed Central

Shewanella oneidensis is able to conserve energy for growth by reducing a wide variety of terminal electron acceptors during anaerobic respiration, including several environmentally hazardous pollutants. This bacterium employs various electron transfer mechanisms for anaerobic respiration, including cell-bound reductases and secreted redox mediators. The aim of this study was to develop rapid tools for profiling the key metabolic changes associated with these different growth regimes and physiological responses. Initial experiments focused on comparing cells grown under aerobic and anaerobic conditions. Fourier transform infrared (FT-IR) spectroscopy with cluster analysis showed that there were significant changes in the metabolic fingerprints of the cells grown under these two culture conditions. FT-IR spectroscopy clearly differentiated cells of S. oneidensis MR-1 cultured at various growth points and cells grown using different electron acceptors, resulting in different phenotypic trajectories in the cluster analysis. This growth-related trajectory analysis is applied successfully for the first time, here with FT-IR spectroscopy, to investigate the phenotypic changes in contrasting S. oneidensis cells. High-performance liquid chromatography (HPLC) was also used to quantify the concentrations of flavin compounds, which have been identified recently as extracellular redox mediators released by a range of Shewanella species. The partial least-squares regression (PLSR) multivariate statistical technique was combined with FT-IR spectroscopy to predict the concentrations of the flavins secreted by cells of S. oneidensis MR-1, suggesting that this combination could be used as a rapid alternative to conventional chromatographic methods for analysis of flavins in cell cultures. Furthermore, coupling of the FT-IR spectroscopy and HPLC techniques appears to offer a potentially useful tool for rapid characterization of the Shewanella cell metabolome in various process environments.

Wang, Hui; Hollywood, Katherine; Jarvis, Roger M.; Lloyd, Jonathan R.; Goodacre, Royston

2010-01-01

267

Characterization of skin abnormalities in a mouse model of osteogenesis imperfecta using high resolution magnetic resonance imaging and Fourier transform infrared imaging spectroscopy.  

PubMed

Evaluation of the skin phenotype in osteogenesis imperfecta (OI) typically involves biochemical measurements, such as histologic or biochemical assessment of the collagen produced from biopsy-derived dermal fibroblasts. As an alternative, the current study utilized non-invasive magnetic resonance imaging (MRI) microscopy and optical spectroscopy to define biophysical characteristics of skin in an animal model of OI. MRI of skin harvested from control, homozygous oim/oim and heterozygous oim/+ mice demonstrated several differences in anatomic and biophysical properties. Fourier transform infrared imaging spectroscopy (FT-IRIS) was used to interpret observed MRI signal characteristics in terms of chemical composition. Differences between wild-type and OI mouse skin included the appearance of a collagen-depleted lower dermal layer containing prominent hair follicles in the oim/oim mice, accounting for 55% of skin thickness in these. The MRI magnetization transfer rate was lower by 50% in this layer as compared to the upper dermis, consistent with lower collagen content. The MRI transverse relaxation time, T2, was greater by 30% in the dermis of the oim/oim mice compared to controls, consistent with a more highly hydrated collagen network. Similarly, an FT-IRIS-defined measure of collagen integrity was 30% lower in the oim/oim mice. We conclude that characterization of phenotypic differences between the skin of OI and wild-type mice by MRI and FT-IRIS is feasible, and that these techniques provide powerful complementary approaches for the analysis of the skin phenotype in animal models of disease. PMID:21845737

Canuto, H C; Fishbein, K W; Huang, A; Doty, S B; Herbert, R A; Peckham, J; Pleshko, N; Spencer, R G

2011-08-15

268

Plasmablastic transformation of multiple myeloma  

Microsoft Academic Search

We describe morphological, immunophenotypic, and cytogenetic characterization of a case of multiple myeloma (MM) that showed plasmablastic transformation at the terminal phase with a picture resembling acute leukemia. The plasmablasts expressed monotypic cytoplasmic immunoglobulin together with myeloid and megakaryocytic markers at disease transformation. Conventional cytogenetic study of bone marrow cells showed coexistence of hypodiploid and hyperdiploid cells, with the former

Cheuk Kwong Lee; Edmond S. K Ma; Tony W. H Shek; Clarence C. K Lam; Wing Yan Au; Thomas S. K Wan; Li Chong Chan

2003-01-01

269

Current transformers  

Microsoft Academic Search

Current transformers are used primarily to measure time varying currents under conditions where some degree of isolation from the primary circuit is desired. In this paper, the basic physics of current transformers is considered and several useful techniques for extending their performance are described. They can be used in an undergraduate laboratory as the basis for very interesting and illustrative

Rodney C. Cross

1986-01-01

270

Transformational Events  

ERIC Educational Resources Information Center

|Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

Denning, Peter J.; Hiles, John E.

2006-01-01

271

Evaluate and characterize mechanisms controlling transport, fate and effects of Army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of red phosphorus-butyl rubber and white phosphorus obscurant smokes: Final report  

Microsoft Academic Search

An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus (red phosphorus-butyl rubber (RP\\/BR)) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke\\/obscurant is currently proceeding. The objective is to characterize the effects of smokes and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States;

P. Van Voris; M. W. Ligotke; K. M. McFadden; S. M. W. Li; B. L. Thomas; D. A. Cataldo; T. R. Garland; J. K. Fredrickson; R. M. Bean; D. W. Carlile

2009-01-01

272

Backlund Transformations as Canonical Transformations.  

National Technical Information Service (NTIS)

Toda and Wadati as well as Kodama and Wadati have shown that the Backlund transformations, for the exponential lattice equation, sine-Gordon equation, K-dV (Korteweg de Vries) equation and modified K-dV equation, are canonical transformations. It is shown...

A. Villani A. H. Zimerman

1977-01-01

273

[Transformation toughening  

SciTech Connect

In NiAl, we have succeeded in determining the complete Ginzburg-Landau strain free energy function necessary to model the cubic to tetragonal martensite transformation in a sample of any size. We believe that this is the first time that the parameters of a Ginzburg-Landau functional and the complete strain spinodal for any three-dimensional displacive transformation were used in simulating the transformation near a crack tip under Mode I loading; the transformation pattern and toughening are different from standard transformation toughening theories. Furthermore, the strain spinodal has an approximately conical shape which can be specified by two material dependent experimentally accessible parameters, rather than the ellipsoidal shape in standard theories. Stress induced martensitic transformation in a polycrystalline sample of NiAl was simulated. In the ZrO[sub 2] system, first principles calculations to determine the semi-empirical potentials for simulating the cubic-tetragonal and tetragonal-monoclinic transformations have been started by doing a more elaborate total energy calculation.In the Al[sub 2]0[sub 3] system, we have discovered that the first principles calculations and semi-empirical potentials have just been completed byanother group in England which we will use instead to base our molecular dynamics simulations on.

Rafa, M.J.

1993-04-19

274

Lightweight transformer  

SciTech Connect

The technical effort described in this report relates to the program that was performed to design, fabricate, and test a lightweight transformer for Strategic Defense Initiative Organization (SDIO) mission requirements. The objectives of this program were two-fold: (1) design and fabricate a lightweight transformer using liquid hydrogen as the coolant; and (2) test the completed transformer assembly with a low voltage, dc power source. Although the full power testing with liquid helium was not completed, the program demonstrated the viability of the design approach. The lightweight transformer was designed and fabricated, and low and moderate power testing was completed. The transformer is a liquid hydrogen cooled air core transformer that uses thin copper for its primary and secondary windings. The winding mass was approximately 12 kg, or 0.03 kg/kW. Further refinements of the design to a partial air core transformer could potentially reduce the winding mass to as low as 4 or 5 kg, or 0.0125 kg/kW. No attempt was made on this program to reduce the mass of the related structural components or cryogenic container. 8 refs., 39 figs., 2 tabs.

Swallom, D.W.; Enos, G.

1990-05-01

275

Characterization of a SV40-transformed rheumatoid synovial fibroblast cell line which retains genotypic expression patterns: A model for evaluation of anti-arthritic agents  

Microsoft Academic Search

Summary  A chimeric Adenovirus-Simian Virus 40 (AdSV40) containing the large T antigen was used to transform rheumatoid synovial fibroblasts.\\u000a A rheumatoid synovial fibroblast cell line was established by infection of primary rheumatoid arthritis (RA) synovial fibroblasts\\u000a at Passage 10 with AdSV40 recombinants followed by selection in semisoft agarose cultures. The transformed cells grew anchor\\u000a independent, exhibited continuous proliferation (>65 passages) in

Huang-Ge Zhang; Warren D. Blackburn; Phillip P. Minghetti

1997-01-01

276

Organelle transformation.  

PubMed

The source of genetic information in a plant cell is contained in nucleus, plastids, and mitochondria. Organelle transformation is getting a lot of attention nowadays because of its superior performance over the conventional and most commonly used nuclear transformation for obtaining transgenic lines. Absence of gene silencing, strong predictable transgene expression, and its application in molecular pharming, both in pharmaceutical and nutraceuticals, are some of many advantages. Other important benefits of utilizing this technology include the absence of transgene flow, as organelles are maternally inherited. This may increase the acceptability of organelle transformation technology in the development of transgenic crops in a wider scale all over the globe. As the need for crop productivity and therapeutic compounds increases, organelle transformation may be able to bridge the gap, thereby having a definite promise for the future. PMID:22610643

Bhattacharya, Anjanabha; Kumar, Anish; Desai, Nirali; Parikh, Seema

2012-01-01

277

Security Transformation.  

National Technical Information Service (NTIS)

For the past 5 years, the United States has sought to transform its defense capabilities to reflect ongoing changes in technology, management techniques, the American political and economic landscapes, and the global security environment. The terrorist at...

S. Metz

2003-01-01

278

Cotton Transformation  

Microsoft Academic Search

Cotton has been cultured in vitro for 37 years, yet even today, some of the culture difficulties that were seen when it was\\u000a first cultured, namely, a very long culture time and a limited number of cultivars that can be cultured, continue to pose\\u000a problems. These inherent tissue culture limitations have made transforming cotton an arduous process. Transforming embryogenic\\u000a callus

D. R. Duncan

279

Covariant Transform  

NASA Astrophysics Data System (ADS)

Dedicated to the memory of Cora Sadosky The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H2, Banach spaces, covariant functional calculus and many others.

Kisil, Vladimir V.

2011-03-01

280

DNA Transformation  

NSDL National Science Digital Library

Stanley Cohen and Herbert Boyer's historic experiment used techniques to cut and paste DNA to create the first custom-made organism containing recombined or 'recombinant' DNA. Cohen and Boyer inserted the recombinant DNA molecule they created into E. coli bacteria by means of a plasmid, thereby inducing the uptake and expression of a foreign DNA sequence known as 'transformation.' This animation from Cold Spring Harbor Laboratory's Dolan DNA Learning Center presents DNA transformation through a series of illustrations of the processes involved.

2012-04-06

281

Transformation toughening  

Microsoft Academic Search

The thermodynamics of the constrained phase transformation is presented with particular reference to size effects introduced by surface phenomena concurrent with the transformation, e.g., the formation of solid-solid surfaces (twins, etc.) and solid-vapour surfaces (microcracks). It is shown that these surface phenomena not only introduce a size-dependent energy term into the total free-energy change, but also reduce the strain energy

F. F. Lange

1982-01-01

282

SHARP transformation  

NASA Astrophysics Data System (ADS)

The U.S. Navy"s SHAred Reconnaissance Pod (SHARP) employs the Recon/Optical, Inc. (ROI) CA-279 dual spectral band (visible/IR) digital cameras operating from an F-18E/F aircraft to perform low-to-high altitude reconnaissance missions. SHARP has proven itself combat worthy, with a rapid transition from development to operational deployment culminating in a highly reliable and effective reconnaissance capability for joint forces operating in Operation Iraqi Freedom (OIF). The U.S. Navy"s intelligence, surveillance and reconnaissance (ISR) roadmap transforms the SHARP system from being solely an independent reconnaissance sensor to a node in the growing Joint ISR network. ROI and the U.S. Navy have combined their resources to ensure the system"s transformation continues to follow the ISR road map. Pre-planned product improvements (P3I) for the CA-270 camera systems will lead the way in that transformation.

Wyatt, Stephan

2004-08-01

283

High-temperature superconducting transformer evaluation  

SciTech Connect

The advancing development of high-temperature superconducting (HTS) materials is encouraging the evaluation of many practical applications. This paper summarizes a study that examined the future potential of HTS power transformers in the 30-MVA to 1000-MVA capacity range. Transformer performance was characterized on the basis of potentially achievable HTS materials capabilities and dominant transformer design parameters. Life-cycle costs were estimated and compared with those of conventional transformers to evaluate the economic viability and market potential of HTS designs. HTS transformers are projected to have both capital and energy cost advantages attributable to their ability to be intrinsically smaller and lighter than conventional transformers of comparable capacity.

DeSteese, J.G.; Dagle, J.E.; Dirks, J.A.

1995-04-01

284

Linear Transformations  

NSDL National Science Digital Library

Created by Stephanie Fitchett of the Connected Curriculum Project, the purpose of this module is to examine linear transformations, particularly those from R^2 to R^2. The is part of a larger collection of learning modules hosted by Duke University.

Fitchett, Stephanie

2010-05-20

285

Transformation & Metamorphosis  

ERIC Educational Resources Information Center

|The sculptures of Canadian artist Brian Jungen are a great inspiration for a lesson on creating new forms. Jungen transforms found objects into unique creations without fully concealing their original form or purpose. Frank Stella's sculpture series, including "K.132,2007" made of stainless steel and spray paint, is another great example of…

Lott, Debra

2009-01-01

286

Holonic transformation  

Microsoft Academic Search

Here introduces a new idea of Holonic Transformation Method (HTM) which is able to represent the huge and complexed systems clearly and precisely as they are expected and the time whenever they are wanted, and which is also able to control them intelligently and flexibly. This idea is originated from Arthur Koestler, the late Hungarian novelist, science writer, and philosopher,

Shigeki Sugiyama

2001-01-01

287

Transforming Schools.  

ERIC Educational Resources Information Center

|The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…

Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.

288

Transforming Schools.  

ERIC Educational Resources Information Center

The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…

Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.

289

Transformation Time  

ERIC Educational Resources Information Center

|The program for the march by librarians on America's capital for the American Library Association (ALA) conference is predictably loaded with lobbying, legislation, and DC tours. It also abounds with professional opportunity and reflects the impact of Leslie Burger, one of the most activist ALA presidents in recent history. Her "Transformation

Berry, John N., III

2007-01-01

290

Transforming Curriculum.  

ERIC Educational Resources Information Center

|Presents comparisons between the traditional curriculum and the essential learnings curriculum implemented at the Moss Point School District in Moss Point, Mississippi. Describes in detail the curriculum transformation process. Provides insight into the role of technology in the reading/language arts curriculum. (RS)|

Cronin, C. H.; Feldman, Phillip

1994-01-01

291

Exploring Transformations  

NSDL National Science Digital Library

In this activity, students will explore transformations of an absolute value function. Step by step instructions guide students in using graphing calculators to examine the effect that stretching and translating has on the coordinates of the graph. Teacher notes and a worksheet are also included to aid in teaching this lesson.

2011-11-25

292

DC Transformer.  

National Technical Information Service (NTIS)

A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply ca...

C. M. Ihlefeld R. C. Youngquist S. O. Starr

2013-01-01

293

Establishment and characterization of equine fibroblast cell lines transformed in vivo and in vitro by BPV-1: Model systems for equine sarcoids  

SciTech Connect

It is now widely recognized that BPV-1 and less commonly BPV-2 are the causative agents of equine sarcoids. Here we present the generation of equine cell lines harboring BPV-1 genomes and expressing viral genes. These lines have been either explanted from sarcoid biopsies or generated in vitro by transfection of primary fibroblasts with BPV-1 DNA. Previously detected BPV-1 genome variations in equine sarcoids are also found in sarcoid cell lines, and only variant BPV-1 genomes can transform equine cells. These equine cell lines are morphologically transformed, proliferate faster than parental cells, have an extended life span and can grow independently of substrate. These characteristics are more marked the higher the level of viral E5, E6 and E7 gene expression. These findings confirm that the virus has an active role in the induction of sarcoids and the lines will be invaluable for further studies on the role of BPV-1 in sarcoid pathology.

Yuan, Z.Q.; Gault, E.A.; Gobeil, P.; Nixon, C.; Campo, M.S. [Institute of Comparative Medicine, University of Glasgow Faculty of Veterinary Medicine, Bearsden Road, Glasgow G61 1QH (United Kingdom); Nasir, L. [Institute of Comparative Medicine, University of Glasgow Faculty of Veterinary Medicine, Bearsden Road, Glasgow G61 1QH (United Kingdom)], E-mail: l.nasir@vet.gla.ac.uk

2008-04-10

294

Experimental and theoretical characterization of the YBa sub 2 Cu sub 3 O sub 7 /YBa sub 2 Cu sub 4 O sub 8 phase transformation  

SciTech Connect

The YBa{sub 2}Cu{sub 4}O{sub 8} to YBa{sub 2}Cu{sub 3}O{sub 7} transformation in mixed phase, superconducting YBaCuO is investigated by high resolution transmission electron microscopy and static lattice, three dimensional, Monte Carlo computer simulations. Micrographs reveal dislocations and stacking faults associated with the transformation that are accurately predicted by the calculations and seen in snapshots'' of the simulated structures. An atomic mechanism involving the intercalation of extra CuO planes by partial dislocation climb is proposed for the YBa{sub 2}Cu{sub 4}O{sub 8}/YBa{sub 2}Cu{sub 3}O{sub 7} phase change. 19 refs., 5 figs.

Fendorf, M.; Burmester, C.P.; Gronsky, R. (Lawrence Berkeley Lab., CA (USA)); Wille, L.T. (Florida Atlantic Univ., Boca Raton, FL (USA). Dept. of Physics)

1990-07-01

295

Establishment and characterization of equine fibroblast cell lines transformed in vivo and in vitro by BPV-1: model systems for equine sarcoids.  

PubMed

It is now widely recognized that BPV-1 and less commonly BPV-2 are the causative agents of equine sarcoids. Here we present the generation of equine cell lines harboring BPV-1 genomes and expressing viral genes. These lines have been either explanted from sarcoid biopsies or generated in vitro by transfection of primary fibroblasts with BPV-1 DNA. Previously detected BPV-1 genome variations in equine sarcoids are also found in sarcoid cell lines, and only variant BPV-1 genomes can transform equine cells. These equine cell lines are morphologically transformed, proliferate faster than parental cells, have an extended life span and can grow independently of substrate. These characteristics are more marked the higher the level of viral E5, E6 and E7 gene expression. These findings confirm that the virus has an active role in the induction of sarcoids and the lines will be invaluable for further studies on the role of BPV-1 in sarcoid pathology. PMID:18191170

Yuan, Z Q; Gault, E A; Gobeil, P; Nixon, C; Campo, M S; Nasir, L

2008-01-11

296

Characterization of near-infrared nonmetal atomic emission from an atmospheric helium microwave-induced plasma using a Fourier transform spectrophotometer  

SciTech Connect

A new approach for using Fourier transform spectroscopy (FTS) for the detection of atomic emission from an atmospheric helium plasma has been developed and the results obtained are described. Among the different types of plasma source available, the atmospheric pressure microwave helium plasma appears to be an efficient excitation source for the determination of nonmetal species. The more complete microwave plasma emission spectra of Cl, Br, I, S, O, P, C, N, and He in the near-infrared region were obtained and their corrected relative emission intensities are reported. This makes qualitative identification simple, and aids in the quantitative analysis of atomic species. The accuracy of the emission wavelengths obtained with the Fourier transform spectrophotometer was excellent and the resolution provided by the FTS allowed certain adjacent emission lines to be adequate for analytical applications.

Hubert, J.; Van Tra, H.; Chi Tran, K.; Baudais, F.L.

1986-08-01

297

In vitro characterization of membrane associated phospholipase C from normal and Kirsten sarcoma virus-transformed NIH 3T3 cells  

SciTech Connect

Transformation of NIH 3T3 cells with Kirsten sarcoma virus (Ki-SV) increased phosphatidylinositol (PI) metabolism. This suggests possible alterations in the phospholipase C (PLC) and PIP/sub 2/-phosphodiesterase (PIP/sub 2/-PDE) activities responsible for hydrolysis of PI and PIP/sub 2/ with Ki-SV transformation. An in vitro assay is employed to study the hydrolysis of exogenously added (/sup 3/H)PI and (/sup 3/H)PIP/sub 2/ with membranes prepared from normal and Ki-SV transformed cells. Association of these activities with membranes appears to be differentially mediated by metals (Ca/sup 2 +/) since chelator treatment dissociates PLC from the particulate fraction. Hydrolysis of PIP/sub 2/ is markedly enhanced (10 fold) by introducing (/sup 3/H)PIP/sub 2/ to membrane preparations in vesicles prepared with excess phosphatidylethanolamine. These activities are dependent on Ca/sup 2 +/ and exhibit a progressive increase in activity between 10/sup -7/M and 10/sup -3/M Ca/sup 2 +/. The optimal pH for PIP/sub 2/-PDE is 7.0, whereas PI specific PLC exhibits optimal activity at pH 5.5. With this in vitro assay system it is possible to demonstrate that GTP-..gamma..-S addition to isolated membranes stimulates PIP/sub 2/-PDE to hydrolyze exogenously added (/sup 3/H)PIP/sub 2/. This should allow direct studies to determine possible differences in GTP-dependent regulation of PI and PIP/sub 2/ hydrolysis with membranes prepared from normal and transformed cells.

Talwar, H.S.; Thomas, T.P.; Bassin, R.; Anderson, W.B.

1986-05-01

298

An X-ray diffraction (XRD) and Fourier transform infrared spectroscopic (FT-IR) characterization of the speciation of arsenic (V) in Portland cement type-V  

Microsoft Academic Search

The speciation of As(V) bearing oxyanions (AsO43?) in cementitious environment has been investigated by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The hydration of Portland cement type-V(OPC-V) was found to be retarded in presence of AsO43?, and the retardation was caused mainly by the formation of highly insoluble calcium arsenate on the surface of hydrating cement particles. Arsenate

M. Yousuf A. Mollah; Felix Lu; David L. Cocke

1998-01-01

299

The development of modulated, quasi-isothermal and ultraslow thermal methods as a means of characterizing the ? to ? indomethacin polymorphic transformation.  

PubMed

While polymorphism remains a key issue within the pharmaceutical and related industries, the understanding of the transformation process itself remains relatively poorly understood. In this study we use a combination of conventional and modulated temperature differential scanning calorimetry (MTDSC), quasi-isothermal MTDSC (Qi-MTDSC) and ultraslow heating rate MTDSC as a novel means of investigating the temperature-induced ? to ? transformation in indomethacin, using hot stage microscopy and variable temperature attenuated total reflectance FTIR spectroscopy as supportive techniques. In particular, we utilize the ability of MTDSC to measure subtle heat capacity changes through the transformation, we examine the use of Lissajous analysis of the modulated heating signal itself (both scanning and quasi-isothermal) and finally we investigate the use of ultraslow heating rates (down to 0.04 °C/min) so as to facilitate examination of the melt-crystallization process at a scanning rate whereby kinetic hindrance becomes negligible. Indomethacin was prepared in the metastable ? and stable ? forms using standard approaches. Samples were studied using conventional DSC, Qi-MTDSC (involving holding and modulating the sample at a series of incremental temperature steps) and ultraslow MTDSC. All studies were conducted using a Q-1000 MTDSC using crimped pans, following standard calibration procedures. Conventional DSC at 10 °C/min showed the expected single melting responses for the ? and ? forms, while MTDSC at slower rates indicated the presence of a melt-crystallization process. Quasi-isothermal studies allowed the heat capacity to be estimated as a function of time, while the associated Lissajous analysis demonstrated distortion of the elliptical response as a result of the kinetic events involved. Ultraslow heating resulted in superimposition of the melting and crystallization processes, resulting in a discrete thermal event that was enthalpically equivalent to the difference between the two processes. It is suggested that these combined thermal methods allow the conversion to be profiled in a manner which facilitates both kinetic and thermodynamic analysis of the transformation. PMID:22449179

Qi, Sheng; Craig, Duncan Q M

2012-04-03

300

Experimental and microstructural characterization of simultaneous creep, plasticity and phase transformation in Ti 50 Pd 40 Ni 10 high-temperature shape memory alloy  

Microsoft Academic Search

The influence of viscoplastic phenomena on the transformation behavior of a Ti50Pd40Ni10 high-temperature shape memory alloy (HTSMA) is investigated by thermomechanical testing followed by transmission electron microscopy (TEM). An ingot of the alloy is fabricated by vacuum arc melting and processed by hot rolling. Cylindrical specimens for compression testing are cut from the rolled bar and standard creep tests and

Parikshith K. Kumar; Dimitris C. Lagoudas

2010-01-01

301

Construction and characterization of a plant transformation-competent BIBAC library of the black Sigatoka-resistant banana Musa acuminata cv. Tuu Gia (AA)  

Microsoft Academic Search

A plant transformation-competent binary bacterial artificial chromosome (BIBAC) library was constructed from Musa acuminata cv. Tuu Gia (AA), a black Sigatoka-resistant diploid banana. After digestion of high-molecular-weight banana DNA by HindIII, several methods of DNA size selection were tested, followed by ligation, using a vector\\/insert molar ratio of 4:1. The library consists of 30,700 clones stored in 80 384-well microtiter

E. Ortiz-Vázquez; D. Kaemmer; H. B. Zhang; J. Muth; M. Rodríguez-Mendiola; C. Arias-Castro; Andrew James

2005-01-01

302

Applications of Open-Path Fourier Transform Infrared for Identification of Volatile Organic Compound Pollution Sources and Characterization of Source Emission Behaviors  

Microsoft Academic Search

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and

Chitsan Lin; Naiwei Liou; Endy Sun; Edwin Corporan; Matthew DeWitt; Chester Spicer; Michael Holdren; Kenneth Cowen; Alex Laskin; David Harris; Richard Shores; Robert Kagann; Ram Hashmonay; Francesca Sprovieri; Nicola Pirrone; Larry Jacobson; Brian Hetchler; David Schmidt; Richard Nicolai; Albert Heber; Ji-Qin Ni; Steven Hoff; Jacek Koziel; Yuanhui Zhang; David Beasley; David Parker; Roxolana Kashuba; Peter Scheff; Aniket Sawant; David Cocker; J. Miller; Tony Taliaferro; David Diaz-Sanchez; William Linn; Kenneth Clark; Henry Gong; Gustavo Olivares; Johan Strom; Christer Johansson; Lars Gidhagen

2008-01-01

303

Characterization of mixed-layer illite-smectite from bentonites using microscopic, chemical, and X-ray methods: Constraints on the smectite-to-illite transformation mechanism  

Microsoft Academic Search

We studied mixed-layer illite-smectite (I\\/S) (,1 or 0.5 mm size fractions) in 28 diage- netic bentonite samples, Pliocene to Ordovician in age, from different locations in North America and Europe to investigate the smectite-to-illite transformation mechanism. XRD- measured illite contents ranged from 3 to 100%, and layer ordering varied continuously from R 5 0t o R$ 3. XRD polytype analysis

JAVIER CUADROS; STEPHEN P. ALTANER

1998-01-01

304

Vectors for cloning in cyanobacteria: Construction and characterization of two recombinant plasmids capable of transformation to Escherichia coli K12 and Anacystis nidulans R2  

Microsoft Academic Search

Two plasmids were constructed consisting of the E. coli vector pACYC184 and the cyanobacterial plasmid pUC1. These recombinants, designated pUC104 and pUC105, can be transformed to E. coli K12 as well as to the cyanobacterium Anacystis nidulans R2 and in both hosts they express their antibiotic markers. pUC104 and pUC105 differ with respect to the location and the orientation of

C. J. Kuhlemeier; W. E. Borrias; C. A. M. J. J. van den Hondel; G. A. van Arkel

1981-01-01

305

Spectroscopic characterization studies of phase transformations in zirconia, hollandite and graphite systems. Final technical report, 14 February 1984-14 October 1985  

SciTech Connect

This document is divided into the following: structural transformation analysis of the ZrO/sub 2/-Y/sub 2/O/sub 3/ system using Raman spectroscopy; effects of incommensurability on the 1-D superionic conductor K - hollandite (K/sub 2x/Mg/sub x/Ti/sub8-x/O/sub 16/; x = 0.77); and effect of high pressure (0 to 25 kbars) on graphite and graphite intercalated compounds. (DLC)

Perry, C.H.

1986-01-01

306

Rapid characterization and identification of fatty acids in margarines using horizontal attenuate total reflectance Fourier transform infrared spectroscopy (HATR-FTIR)  

Microsoft Academic Search

Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate\\u000a analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and\\u000a to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were\\u000a analyzed in terms of fatty acid profile, total fat, moisture,

Maylet Hernández-Martínez; Tzayhri Gallardo-Velázquez; Guillermo Osorio-Revilla

2010-01-01

307

DNA Sequence and Characterization ofHaemophilus influenzae dprA1, a Gene Required for Chromosomal but Not Plasmid DNA Transformation  

Microsoft Academic Search

to encode a 41.6-kDa polypeptide that was required for efficient chromosomal but not plasmid DNA transfor- mation. Analysis of the deduced amino acid sequence of DprA suggested that it may be an inner membrane protein, which is consistent with its apparent role in DNA processing during transformation. Four other open reading frames (ORFs) on the cloned DNA segment were identified.

SUREKHA KARUDAPURAM; XUMEI ZHAO; ANDGERARD J. BARCAK

1995-01-01

308

Construction and characterization of a plant transformation-competent BIBAC library of the black Sigatoka-resistant banana Musa acuminata cv. Tuu Gia (AA).  

PubMed

A plant transformation-competent binary bacterial artificial chromosome (BIBAC) library was constructed from Musa acuminata cv. Tuu Gia (AA), a black Sigatoka-resistant diploid banana. After digestion of high-molecular-weight banana DNA by HindIII, several methods of DNA size selection were tested, followed by ligation, using a vector/insert molar ratio of 4:1. The library consists of 30,700 clones stored in 80 384-well microtiter plates. The mean insert size was estimated to be 100 kb, and the frequency of inserts with internal NotI sites was 61%. The majority of insert sizes fell into the range of 100+/-20 kb, making them suitable for Agrobacterium-mediated transformation. Only 1% and 0.9% of the clones contain chloroplast and mitochondrial DNA, respectively. This is the first BIBAC library for banana, estimated to represent five times its haploid genome (600 Mbp). It was demonstrated by hybridization that the library contains typical members of resistance gene and defense gene families that can be used for transformation of disease susceptible banana cultivars for banana genetic improvement. PMID:15650812

Ortiz-Vázquez, E; Kaemmer, D; Zhang, H-B; Muth, J; Rodríguez-Mendiola, M; Arias-Castro, C; James, Andrew

2005-01-14

309

Subsurface characterization of an oxidation-induced phase transformation and twinning in nickel-based superalloy exposed to oxy-combustion environments  

SciTech Connect

In the integration of oxy-fuel combustion to turbine power generation system, turbine alloys are exposed to high temperature and an atmosphere comprised of steam, CO{sub 2} and O{sub 2}. While surface and internal oxidation of the alloy takes place, the microstructure in the subsurface region also changes due to oxidation. In this study, bare metal coupons of Ni-base superalloys were exposed in oxy-fuel combustion environment for up to 1000 h and the oxidation-related microstructures were examined. Phase transformation occurred in the subsurface region in Ni-based superalloy and led to twinning. The transformation product phases were analyzed through thermodynamic equilibrium calculations and various electron microscopy techniques, including scanning electron microscopy (SEM), orientation imaging microscopy (OIM) and transmission electron microscopy (TEM). The mechanism by which the phase transformation and the formation of the microstructure occurred was also discussed. The possible effects of the product phases on the performance of the alloy in service were discussed.

Zhu, Jingxi; Holcomb, Gordon R.; Jablonski, Paul D.; Wise, Adam; Li, Jia; Laughlin, David E.; Sridhar, Seetharaman

2012-07-30

310

Transformations Journal  

NSDL National Science Digital Library

Different forms of communication have always had a tendency to transform interactions and everyday life in ways that have surprised people from many different backgrounds. Academics have long been interested in such dynamic transformations, and this electronic journal represents one of the responses to such processes. As their site notes, this journal is "dedicated to the exploration of ideas, issues and debates emerging out of contemporary global culture." Visitors to the site can read the complete version of every issue on the site, and they will be pleased to find such intriguing titles as "Rethinking Regionality", "Accidental Environments", and "Fleeing the City". Interested parties can also consult the site to learn about the journal's editorial board, their calls for papers, submission guidelines, and related links.

311

Transformative learning.  

PubMed

The whole point of teaching and training is to have the learners leave in some way different from how they came in-more skilled, more knowledgeable, more self-aware. Transformative learning refers to dramatic change, where the learner achieves a shift in perspective. This shift results from a critical examination of one's own assumptions, values, and beliefs, and of the foundations and expectations of the system in which one operates. Educators are in the change business, and educators focused on implementing psychiatric rehabilitation, recovery-oriented services, and person-centered planning are in the transformative learning business. The shift from a traditional medical model to a recovery perspective, the shift from "illness" to "disability" to "wellness," and the shift from risk prevention to promoting opportunities for growth all require "standing outside ourselves" and looking at a "stark and highlighted picture" of the all-too-common status quo of mental health services today. With the right approach, learners can be developed, encouraged, disrupted, and transformed. PMID:23276245

Nemec, Patricia B

2012-12-01

312

Transformation plasmonics  

NASA Astrophysics Data System (ADS)

Surface plasmons polaritons (SPPs) at metal/dielectric interfaces have raised lots of expectations in the on-going quest towards scaling down optical devices. SPP optics offers a powerful and flexible platform for real two-dimensional integrated optics, capable of supporting both light and electrons. Yet, a full exploitation of the features of SPPs is conditioned by an accurate control of their flow. Most efforts have so far focused on the extrapolation of concepts borrowed from guided optics. This strategy has already led to many important breakthroughs but a fully deterministic control of SPP modes remains a challenge. Recently, the field of optics was stimulated by a novel paradigm, transformation optics, which offers the capability to control light flow in any desired fashion. While it has already significantly contributed to the design of metamaterials with unprecedented optical properties, its versatility offers new opportunities towards a fully deterministic control of SPPs and the design of a new class of plasmonic functionalities. Here, we review recent progress in the application of transformation optics to SPPs. We first briefly describe the theoretical formalism of transformation plasmonics, focusing on its specificities over its three-dimensional optical counterpart. Numerical simulations are then used to illustrate its capability to tame SPP flows at a metal interface patterned with a dielectric load. Finally, we review recent experimental implementations leading to unique SPP functionalities at optical frequencies.

Kadic, Muamer; Guenneau, Sébastien; Enoch, Stefan; Huidobro, Paloma A.; Martín-Moreno, Luis; García-Vidal, Francisco J.; Renger, Jan; Quidant, Romain

2012-07-01

313

Isolation and characterization of a novel mitogenic regulatory gene, 322, which is transcriptionally suppressed in cells transformed by src and ras.  

PubMed Central

In an attempt to isolate novel regulatory and/or tumor suppressor genes, we identified cDNAs whose abundance is low in NIH 3T3 cells and further decreased following the expression of the activated oncogene, v-src. The transcription of one such gene, 322, is suppressed at least 15-fold in src-, ras-, and fos-transformed cells and 3-fold in myc-transformed cells but is unaffected in raf-, mos-, or neu-transformed cells. Activation of a ts-v-src allele in confluent 3Y1 fibroblasts resulted in an initial increase in 322 mRNA levels after 1 to 2 h followed by a rapid decrease to suppressed levels after 4 to 8 h. Morphological transformation was not detected until 12 h later, indicating that the accumulation of 322 transcripts is regulated by v-src and not as a consequence of transformation. Addition of fetal calf serum to starved subconfluent NIH 3T3 or 3Y1 fibroblasts resulted in a similar biphasic regulation of 322, indicating that 322 transcription is responsive to mitogenic factors. Sequence analysis of a putative full-length 322 cDNA clone (5.4 kb) identified a large open reading frame (ORF) encoding a 148.1-kDa product. In vitro transcription and translation of the 322 cDNA from a T7 promoter resulted in a 207-kDa product whose electrophoretic mobility on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel was unaffected by digestion with endoglycosidase F. The discrepancy in predicted versus measured molecular weights may result from the high percentage of acidic residues (roughly 20% Glu or Asp) in the 322 ORF product. Comparison of the 322 cDNA ORF with sequences in data banks indicates that this gene is novel. The 322 ORF product contains a potential Cys-1-His-3 Zn finger, at least five nuclear localization signals of the adenovirus E1a motif K(R/K)X(R/K), and alternating acidic and basic domains. Overexpression of the 322 cells resulted in the selection of rapidly growing cells which had lost the transduced 322 cDNA. Thus, 322 represent a novel src- and ras-regulated gene which encodes a potential regulator of mitogenesis and/or tumor suppressor.

Lin, X; Nelson, P J; Frankfort, B; Tombler, E; Johnson, R; Gelman, I H

1995-01-01

314

Cloning and characterization of a novel stress-responsive WRKY transcription factor gene (MusaWRKY71) from Musa spp. cv. Karibale Monthan (ABB group) using transformed banana cells.  

PubMed

WRKY transcription factor proteins play significant roles in plant stress responses. Here, we report the cloning and characterization of a novel WRKY gene, MusaWRKY71 isolated from an edible banana cultivar Musa spp. Karibale Monthan (ABB group). MusaWRKY71, initially identified using in silico approaches from an abiotic stress-related EST library, was later extended towards the 3' end using rapid amplification of cDNA ends technique. The 1299-bp long cDNA of MusaWRKY71 encodes a protein with 280 amino acids and contains a characteristic WRKY domain in the C-terminal half. Although MusaWRKY71 shares good similarity with other monocot WRKY proteins the substantial size difference makes it a unique member of the WRKY family in higher plants. The 918-bp long 5' proximal region determined using thermal asymmetric interlaced-polymerase chain reaction has many putative cis-acting elements and transcription factor binding motifs. Subcellular localization assay of MusaWRKY71 performed using a GFP-fusion platform confirmed its nuclear targeting in transformed banana suspension cells. Importantly, MusaWRKY71 expression in banana plantlets was up-regulated manifold by cold, dehydration, salt, ABA, H2O2, ethylene, salicylic acid and methyl jasmonate treatment indicating its involvement in response to a variety of stress conditions in banana. Further, transient overexpression of MusaWRKY71 in transformed banana cells led to the induction of several genes, homologues of which have been proven to be involved in diverse stress responses in other important plants. The present study is the first report on characterization of a banana stress-related transcription factor using transformed banana cells. PMID:21110110

Shekhawat, Upendra K Singh; Ganapathi, Thumballi R; Srinivas, Lingam

2010-11-26

315

Isolation and Characterization of a Rat Liver Epithelial Cell Line Resistant to the Antiproliferative Effects of Transforming Growth Factor 0 (Type 1)  

Microsoft Academic Search

Rat liver epithelial cells resistant to the growth-inhibitory effects of transforming growth factor 0, (TGF-^i) were isolated after 3 h exposure to 1.5 Mg\\/mlof TV-methyl-iV'-nitro-A'-nitrosoguanidine followed by con tinuous treatment with 1 ng\\/ml TGF-\\/?i for 6 weeks. In comparison to the parental or \\/V-methyU\\/V'-nitro-A'-nitrosoguanidine-exposedrat liver epithelial cells (concentration causing 50% inhibition of the rate of DNA synthesis, 0.25 ng\\/ml), these

Mrunal S. Chapekar; Anthony C. Huggett; Caroline C. Cheng; Lori L. Hampton; Snorri S. Thorgeirsson

316

Characterization of the plasminogen activator of herpesvirus-transformed cells and examination of its correlation with the tumorigenic and metastatic ability of in vivo-derived sublines  

SciTech Connect

Herpes simplex virus type 2-transformed hamster embryo fibroblasts (333-8-9 cells) produce increased amounts of plasminogen activator (PA) compared with normal hamster cells. The 333-8-9 PA activity was quantitated in comparison to a PA standard, urokinase (UK). Using a direct PA assay in which /sup 125/I-labeled plasminogen is cleaved, a linear dose-response was seen over a 1000-fold range in UK concentration when plotted on a semi-logarithmic scale. Extracellular PA activity secreted by the HSV-2-transformed cell line, 333-8-9, followed a similar dose-response slop. The optimum pH and osmolarity for detection of the 333-8-9 extracellular PA activity were pH 8.9 and approximately 150 mOsmol, respectively. Secretion of PA by the 333-8-9 cells did not vary significantly on a per cell basis over cell densities ranging from 0.1 to 8.0 x 10/sup 7/ cells/T-75 cm/sup 2/ flask. This assay was accurate, reproducible, and demonstrated that the 333-8-9 cells produced at least a 20-fold greater amount of PA activity than their normal cell counterparts. Based on the molecular weight (50-58 Kd) of the secreted 333-8-9 cell PA and lack of fibrin stimulation of the PA activity, it is concluded to be a urokinase-type PA.

Marks, G.J.

1986-01-01

317

Isolation and characterization of novel ginsenoside-hydrolyzing glycosidase from Microbacterium esteraromaticum that transforms ginsenoside Rb2 to rare ginsenoside 20(S)-Rg3.  

PubMed

Ginsenoside Rb2 was transformed by recombinant glycosidase (Bgp2) into ginsenosides Rd and 20(S)-Rg3. The bgp2 gene consists of 2,430 bp that encode 809 amino acids, and this gene has homology to the glycosyl hydrolase family 2 protein domain. SDS-PAGE was used to determine that the molecular mass of purified Bgp2 was 87 kDa. Using 0.1 mg ml(-1) of enzyme in 20 mM sodium phosphate buffer at 40 °C and pH 7.0, 1.0 mg ml(-1) ginsenoside Rb2 was transformed into 0.47 mg ml(-1) ginsenoside 20(S)-Rg3 within 120 min, with a corresponding molar conversion yield of 65 %. Bgp2 hydrolyzed the ginsenoside Rb2 along the following pathway: Rb2 ? Rd ? 20(S)-Rg3. This is the first report of the biotransformation of ginsenoside Rb2 to ginsenoside 20(S)-Rg3 using the recombinant glycosidase. PMID:23670791

Quan, Lin-Hu; Wang, Chao; Jin, Yan; Wang, Ting-Rui; Kim, Yeon-Ju; Yang, Deok Chun

2013-05-14

318

Degradation and mineralization of 2-chloro-, 3-chloro- and 4-chlorobiphenyl by a newly characterized natural bacterial strain isolated from an electrical transformer fluid-contaminated soil.  

PubMed

A bacterium classified as Achromobacter xylosoxidans strain IR08 by phenotypic typing coupled with 16S rRNA gene analysis was isolated from a soil contaminated with electrical transformer fluid for over sixty years using Aroclor 1221 as an enrichment substrate. The substrate utilization profiles revealed that IR08 could grow on all three monochlorobiphenyls (CBs), 2,4'- and 4,4'-dichlorobiphenyl as well as 2-chlorobenzoate (2-CBA), 3-CBA, 4-CBA, and 2,3-dichlorobenzoate. Unusually, growth was poorly sustained on biphenyl and benzoate. In growth experiments, IR08 degraded all CBs (0.27 mmol/L) in less than 96 h with concomitant stoichiometric release of inorganic chloride and growth yields were 2-3 times higher than those observed on biphenyl. In contrast to most of the chlorobiphenyl-degrading strains described in the literature, which are reported to form CBA, no metabolite was identified in the culture broth by HPLC analysis. When co-incubated with respective CBs and biphenyl, strain IR08 preferentially utilized the chlorinated analogues in less than 96 h while it took another 264 h before 90% of the initially supplied biphenyl could be degraded. The promotion of co-metabolic transformation of halogenated substrates by the inclusion of their non-halogenated derivatives may not therefore, result in universal benefits. PMID:19143351

Ilori, Matthew O; Robinson, Gary K; Adebusoye, Sunday A

2008-01-01

319

In-situ CIR-FTIR (cylindrical internal reflection/Fourier transform infrared) characterization of salicylate complexes at the goethite/aqueous solution interface  

SciTech Connect

The types of complexes that salicylate (2-hydroxy-benzoate) forms with the surface of goethite ({alpha}-FeOOH) in aqueous medium were studied in situ by using cylindrical internal reflection (CIR) Fourier transform infrared (FTIR) spectroscopy. Results obtained from CIR-FTIR studies were compared with adsorption isotherm experiments in order to relate the level of salicylate coverage to the nature of the surface complex. At lower surface coverages all the interfacial salicylate has a chelate structure in which one carboxylic oxygen and the ortho phenolic oxygen bind one Fe atom of the goethite surface. At higher surface coverages this chelate complex coexists with salicylate ions, which are weakly bound in the double layer.

Yost, E.C.; Tejedor-Tejedor, M.I.; Anderson, M.A. (Univ. of Wisconsin, Madison (USA))

1990-06-01

320

Real time monitoring of the electrochemical transformation of a ferrocene-terminated alkanethiolate monolayer at gold via an adhesion-based atomic force microscopic characterization  

SciTech Connect

This paper demonstrates the real time monitoring of the electrochemical transformation of a surface-bound redox species using AFM-based adhesion measurements. The measurements were conducted using a monolayer formed by the chemisorption of 11-mercaptoundecyl ferrocenecarboxylate (FcT) at a Au(111) electrode and a gold-coated probe tip modified with an octadecanethiolate (OT) monolayer. Using this probe tip-sample combination, the one-electron oxidation of the ferrocenyl group of FcT monolayer results in a decrease in the observed force of adhesion (F{sub ad}) at the microcontact formed by the two different surfaces. Using surface tension arguments, this change is attributed to the decrease in the effective miscibility at the microcontact as a consequence of the oxidation of the ferrocenyl group to the ferrocenium ion. Issues related to the underlying changes in the interfacial structure that give rise to the differences in F{sub ad} are discussed. 36 refs., 3 figs.

Green, J.B.D.; McDermott, M.T.; Porter, M.D. [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States)

1996-08-01

321

Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis  

NASA Astrophysics Data System (ADS)

This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant materials identified in the sticks were zinc and titanium white, chrome yellow, yellow and red ochre, vermillion, alizarin, indigo, Prussian and synthetic ultramarine blue. The results also showed that calcite and barite were used as inorganic mineral fillers while Arabic gum was the medium used. EDXRF offered great potential for such investigations since it allowed the identification of the elements present in the sample preserving its integrity. However, this information alone was not enough to clearly identify some of the materials in study and therefore it was necessary to use XRD and FTIR techniques.

Manso, M.; Valadas, S.; Pessanha, S.; Guilherme, A.; Queralt, I.; Candeias, A. E.; Carvalho, M. L.

2010-04-01

322

Use of wavelet-packet transforms to develop an engineering model for multifractal characterization of mutation dynamics in pathological and nonpathological gene sequences  

NASA Astrophysics Data System (ADS)

This study uses dynamical analysis to examine in a quantitative fashion the information coding mechanism in DNA sequences. This exceeds the simple dichotomy of either modeling the mechanism by comparing DNA sequence walks as Fractal Brownian Motion (fbm) processes. The 2-D mappings of the DNA sequences for this research are from Iterated Function System (IFS) (Also known as the ``Chaos Game Representation'' (CGR)) mappings of the DNA sequences. This technique converts a 1-D sequence into a 2-D representation that preserves subsequence structure and provides a visual representation. The second step of this analysis involves the application of Wavelet Packet Transforms, a recently developed technique from the field of signal processing. A multi-fractal model is built by using wavelet transforms to estimate the Hurst exponent, H. The Hurst exponent is a non-parametric measurement of the dynamism of a system. This procedure is used to evaluate gene- coding events in the DNA sequence of cystic fibrosis mutations. The H exponent is calculated for various mutation sites in this gene. The results of this study indicate the presence of anti-persistent, random walks and persistent ``sub-periods'' in the sequence. This indicates the hypothesis of a multi-fractal model of DNA information encoding warrants further consideration. This work examines the model's behavior in both pathological (mutations) and non-pathological (healthy) base pair sequences of the cystic fibrosis gene. These mutations both natural and synthetic were introduced by computer manipulation of the original base pair text files. The results show that disease severity and system ``information dynamics'' correlate. These results have implications for genetic engineering as well as in mathematical biology. They suggest that there is scope for more multi-fractal models to be developed.

Walker, David Lee

1999-12-01

323

Hough Transform from the Radon Transform  

Microsoft Academic Search

An appropriate special case of a transform developed by J. Radon in 1917 is shown to have the major properties of the Hough transform which is useful for finding line segments in digital pictures. Such an observation may be useful in further efforts to generalize the Hough transform. Techniques for applying the Radon transform to lines and pixels are developed

Stanley R. Deans

1981-01-01

324

Physical transformations in solvated pharmaceuticals  

Microsoft Academic Search

Understanding the properties of solid-state compounds, especially solvated drugs, is very important during process\\/product development. The stability and performance of such solvated drugs can vary drastically with variations in processing and storage conditions. Therefore, it becomes imperative to properly document and control the crystal form present in the formulation. A systematic attempt to characterize phase transformations in solvates and hydrates

Vidya Joshi

1998-01-01

325

An integrated approach to characterization of microbial exudates and investigation of their role in the spatial distribution and transformations of uranium at the mineral-microbe interface  

SciTech Connect

The long-term aim of this project was to understand the role of microbiota and their polymers (EPS) in controlling the distribution and fates of contaminants in subsurface environments. Additionally, this project also focused on the identification and characterization of extracellular proteins under a variety of growth conditions. Finally, this project sought to develop and advance the use of a variety of synchrotron-based hard-x-ray techniques to address a number of different ERSP elements.

Kemner, K.M.; O'Loughlin, E.J.; Kelly, S.D.; Nealson, K.H.

2006-06-01

326

Characterization of the acidity of ultrastable Y, mordenite, and ZSM-12 via NH 3stepwise temperature programmed desorption and Fourier transform infrared spectroscopy  

Microsoft Academic Search

The acidity of ultrastable Y (USY), mordenite, and ZSM-12 of variable Si\\/Al ratios has been characterized by coupling NH3-stepwise temperature programmed desorption (STPD) and FT-IR. The former technique allows us to quantify accurately the ammonia chemisorbed on acid sites of different strengths. In contrast to other acidic oxide catalysts, it was found that protonated zeolites possess distinct limits of acid

Wenmin Zhang; Eric C. Burckle; Panagiotis G. Smirniotis

1999-01-01

327

In situ Fourier transform infrared characterization of the plasma chemistry in varying pulsed cycles of a 1,3-butadiene discharge in an inductively coupled gaseous electronics conference cell  

SciTech Connect

In situ Fourier transform infrared spectroscopy is used to characterize the plasma chemistry of pulsed 1,3-butadiene (H{sub 2}C=CHCH=CH{sub 2}) discharges subject to varying percentages of the duty cycle in a gaseous electronics conference cell. Variations in densities associated with the major observed spectral bands are closely examined as a function of duty cycle. The possible dissociation mechanisms responsible for all observed vibrations are investigated. For example, the data show that about 44% of CH{sub 2} stretching vibrations during continuous wave biasing are due to free CH{sub 2} daughter species, while only bound CH{sub 2} are observed during pulsing of the discharge. This indicates that only the {pi} bond of the C=C bond is cleaved during pulsed mode operation, with the {sigma} being cleaved during cw biasing.

Jindal, A.K.; Prengler, A.J.; Overzet, L.J.; Goeckner, M.J. [Department of Electrical Engineering and Computer Science, University of Texas at Dallas, 2601 North Floyd Drive, Richardson, Texas 75083 (United States)

2006-01-15

328

Replicating, differentiated macrophages can serve as in vitro targets for transformation by avian myeloblastosis virus.  

PubMed Central

Pure cultures of chicken macrophages were characterized functionally and transformed by avian myeloblastosis virus. Transformed cells exhibited an altered function. The efficiency of transformation was limited by the mitotic activity of the macrophages. Images

Durban, E M; Boettiger, D

1981-01-01

329

EDITORIAL: Transformation optics Transformation optics  

NASA Astrophysics Data System (ADS)

Metamaterials are artificial materials with versatile properties that can be tailored to fit almost any practical need and thus go well beyond what can be obtained with `natural' materials. Recent progress in developing optical metamaterials allows unprecedented extreme control over the flow of light at both the nano- and macroscopic scales. The innovative field of transformation optics, which is enabled by metamaterials, inspired researchers to take a fresh look at the very foundations of optics and helped to create a new paradigm for the science of light. Similar to general relativity, where time and space are curved, transformation optics shows that the space for light can also be bent in an almost arbitrary way. Most importantly, the optical space can be designed and engineered, opening up the fascinating possibility of controlling the flow of light with nanometer spatial precision. This new paradigm enables a number of novel optical devices guiding how, using metamaterials, the space for light can be curved in a pre-designed and well-controlled way. Metamaterials which incorporate the innovative theories of transformation optics are pertinent to the important areas of optical cloaking, optical black holes, super-resolution imaging, and other sci-fi-like devices. One such exciting device is an electromagnetic cloak that can bend light around itself, similar to the flow of water around a stone, making invisible both the cloak and the object hidden inside. Another important application is a flat hyperlens that can magnify the nanometer-scale features of an object that cannot be resolved with conventional optics. This could revolutionize the field of optical imaging, for instance, because such a meta-lens could become a standard add-on tool for microscopes. By enabling nanoscale resolution in optical microscopy, metamaterial-based transformation optics could allow one to literally see extremely small objects with the eye, including biological cells, viruses, and possibly even DNA molecules. Light-concentrating devices, such as the optical black hole, can be used for efficient solar light collection in photovoltaic elements for renewable energy. With the dramatic advances in micro- and nanofabrication methods, we are presented with the opportunity to control light in a way that was not possible with the materials provided to us by nature. In an artificial pattern of sub-wavelength elements, the propagation of electromagnetic energy can be defined by an equivalent spatial and spectral dispersion of effective dielectric and magnetic properties. These synthetic structures, which can be fabricated with a desired spatial distribution of effective permittivity epsilon(r) and permeability ?(r), offer a unique potential to guide and control the flow of electromagnetic energy in such an engineered optical space. No longer are we constrained by the electromagnetic response of natural materials and their chemical compounds. Instead, we can tailor the shape and size of the structural units of the metamaterials, or tune their composition and morphology to provide new functionality.

Shalaev, Vladimir M.; Pendry, John

2011-02-01

330

The time domain response of BCI transformers  

Microsoft Academic Search

A representative bulk current injection transformer is characterized experimentally in both the time and frequency domains with the goal of quantitatively predicting its time domain response to the trapezoidal pulse specified in MIL-STD 461E. The time domain responses of the representative transformer, as computed from the experimentally obtained frequency domain transfer function and measured directly in the time domain, are

James McLean; Robert Sutton

2009-01-01

331

Enterprise transformation :lessons learned, pathways to success.  

SciTech Connect

In this report, we characterize the key themes of transformation and tie them together in a ''how to'' guide. The perspectives were synthesized from strategic management literature, case studies, and from interviews with key management personnel from private industry on their transformation experiences.

Slavin, Adam M.; Woodard, Joan Brune

2006-05-01

332

Biomorphic transformation to obtain hierarchical porous structures  

Microsoft Academic Search

Hydroxyapatite (HA) bone scaffolds characterized by highly organized hierarchical structures have been obtained by chemically transforming native woods through a sequence of thermal and hydrothermal processes. The five steps of the phase transformation process have been set up in order to achieve total phase conversion and purity maintaining the original native microstructure. The composition of the final wood-derived scaffolds was

A. Ruffini; S. Sprio; A. Tampieri

2009-01-01

333

Band gap shift, structural characterization and phase transformation of CdSe thin films from nanocrystalline cubic to nanorod hexagonal on air annealing  

NASA Astrophysics Data System (ADS)

Cadmium selenide (CdSe) thin films were deposited on a glass substrate using the chemical bath deposition method at room temperature. The films were deposited using cadmium acetate as a Cd2+ ion source and sodium selenosulfate as a Se2- ion source. The 'as-deposited' CdSe thin films are red in colour and specularly reflective. The 'as-deposited' CdSe layers grew with nanocrystalline cubic phase along with some amorphous phase present, with an optical band gap 'Eg' of 2.3 eV and electrical resistivity of the order of 105-106 ? cm. The 'as-deposited' film is annealed in air at 673 K for 4 h and the effect of annealing on structural, morphological, optical and electrical properties is studied. It is worth noting that after annealing, metastable nanocrystallite cubic phase transforms into stable well crystalline hexagonal phase and films show a 'redshift' of '0.6 eV' in their optical band gap 'Eg'. After annealing, the crystallites' size increases from 45 Å to 180 Å, which results in a decrease in electrical resistivity. These changes have been attributed to the crystallite size dependent properties of CdSe semiconductor thin films.

Kale, R. B.; Lokhande, C. D.

2005-01-01

334

Contribution made by multivariate curve resolution applied to gel permeation chromatography-Fourier transform infrared data for an in-depth characterization of styrene-butadiene rubber blends.  

PubMed

We evaluate the contribution made by multivariate curve resolution-alternating least squares (MCR-ALS) for resolving gel permeation chromatography-Fourier transform infrared (GPC-FT-IR) data collected on butadiene rubber (BR) and styrene butadiene rubber (SBR) blends in order to access in-depth knowledge of polymers along the molecular weight distribution (MWD). In the BR-SBR case, individual polymers differ in chemical composition but share almost the same MWD. Principal component analysis (PCA) gives a general overview of the data structure and attests to the feasibility of modeling blends as a binary system. MCR-ALS is then performed. It allows resolving the chromatographic coelution and validates the chosen methodology. For SBR-SBR blends, the problem is more challenging since the individual elastomers present the same chemical composition. Rank deficiency is detected from the PCA data structure analysis. MCR-ALS is thus performed on column-wise augmented matrices. It brings very useful insight into the composition of the analyzed blends. In particular, a weak change in the composition of individual SBR in the MWD's lowest mass region is revealed. PMID:18935830

Ruckebusch, C; Vilmin, F; Coste, N; Huvenne, J P

2008-07-01

335

The Use of Accurate Mass Tags based upon High-Throughput Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Global Proteomic Characterization  

SciTech Connect

In this review, we describe the technological basis and progress towards a new global proteomics strategy that uses peptide accurate mass measurements augmented by information from separations (e.g. LC retention times) to provide large improvements in sensitivity, dynamic range, comprehensiveness and throughput. The use of ?accurate mass and time? (AMT) tags serves to eliminate the need for routine MS/MS measurements [#4109]. As the case study, we use our own research efforts to illustrate the role of AMTs within the broader context of a state-of-the-art proteomics effort. Our strategy exploits high-resolution capillary LC separations combined with Fourier transform ion cyclotron resonance mass spectrometry (FTICR). AMTs represent peptide biomarkers and can be used to confidently identify proteins based on the high mass measurement accuracy provided by FTICR combined with LC elution times. Once identified using MS/MS, these biomarkers provide the foundation for subsequent high throughput studies using only AMT tags to identify and quantify the proteins expressed within a cell system. Key attractions of this approach include the feasibility of completely automated high confidence protein identifications, extensive proteome coverage, and the capability for exploiting stable-isotope labeling methods for high precision abundance measurements [#4019]. Additional developments described in this review include methods for more effective coverage of membrane proteins [#4184], for dynamic range expansion of proteome measurements [#4012], and for multi-stage separations that promise to enable more focused analyses, further extend the quality of measurements, and also extend measurements to more complex proteomes.

Camp, David G.; Smith, Richard D.

2004-07-30

336

Applications of open-path Fourier transform infrared for identification of volatile organic compound pollution sources and characterization of source emission behaviors.  

PubMed

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and 2-butanone were identified in the southeast direction where paint solvent manufacturing processes are located. However, an attempt to uncover sources of styrene was not successful because the method detection limit (MDL) of the OP-FTIR system was not sensitive enough to produce conclusive data. In the second scenario, the OP-FTIR system was set up in an industrial complex to distinguish the origins of several VOCs. Eight major VOCs were identified in the ambient environment. The pollutant detected wind-rose percentage plots that clearly showed that ethylene, propylene, 2-butanone, and toluene mainly originated from the tank storage area, whereas the source of n-butane was mainly from the butadiene manufacturing processes of the refinery plant, and ammonia was identified as an accompanying reduction product in the gasoline desulfuration process. Advantages of OP-FTIR include its ability to simultaneously and continuously analyze many compounds, and its long path length monitoring has also shown advantages in obtaining more comprehensive data than the traditional multiple, single-point monitoring methods. PMID:18581812

Lin, Chitsan; Liou, Naiwei; Sun, Endy

2008-06-01

337

Pseudomorphic transformation of amorphous silica microtubes into mesoporous MCM-41 type silica tubes. Synthesis, characterization and surface functionalization with titania, vanadia and zirconia.  

PubMed

Silica tubes with MCM-41 type mesostructures were successfully synthesized by a combination of the Stoeber process and a pseudomorphic transformation using electrospun macrosized polystyrene fibres as structure directing templates. Two different morphologies of mesoporous silica tubes are accessible with this method: a hollow morphology with tunable silica wall thickness and with a mesoporous silica shell structure and a core containing amorphous silica. All one dimensional tube like porous silica materials have a high specific surface area of approximately 1000 m(2) g(-1) with well-ordered hexagonal mesopores. Grafting of Ti, V and Zr metallocene dichloride molecular complexes has been employed resulting in the deposition of titanium-, vanadium-, zirconium-oxide in the interior of the silica tubes after ceramisation of the green body composites. The respective oxides were coated on top of the inner mesoporous silica surface of the tubes. Such silica based hybrids might be potential support materials in heterogeneous catalysis (e.g. vanadia) as well as interesting catalysts for photocatalysis (for TiO(2), ZrO(2)). All materials were characterised by X-ray diffraction (SAXS and XRD), nitrogen adsorption at 77 K, UV/VIS diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). PMID:23168912

Patzsch, Julia; Schneider, Jörg J

2012-11-20

338

Quantum transformations  

SciTech Connect

We show that the quantum Hamilton-Jacobi equation can be written in the classical form with the spatial derivative {partial_derivative}{sub q} replaced by {partial_derivative}{sub q} with dq = dq/{radical}1{minus}{beta}{sup 2}(q), where {beta}{sup 2}(q) is strictly related to the quantum potential. This can be seen as the opposite of the problem of finding the wave function representation of classical mechanics as formulated by Schiller and Rosen. The structure of the above {open_quotes}quantum transformation{close_quotes}, related to the recently formulated equivalence principle, indicates that the potential deforms space geometry. In particular, a result by Flanders implies that both W(q) = V(q) {minus} E and the quantum potential Q are proportional to the curvatures {kappa}{sub W} and {kappa}{sub Q} which arise as natural invariants in an equivalence problem for curves in the projective line. In this formulation the Schroedinger equation takes the geometrical form ({partial_derivative}{sub q}{sup 2} + {kappa}{sub W}){psi} = 0.

Faraggi, A.E. [Univ. of Florida, Gainesville, FL (United States). Institute for Fundamental Theory; Matone, M. [Univ. of Padova (Italy). Dept. of Physics G. Galilei

1998-01-09

339

Biosynthesis of homoeriodictyol from eriodictyol by flavone 3'-O-methyltransferase from recombinant Yarrowia lioplytica: Heterologous expression, biochemical characterization, and optimal transformation.  

PubMed

In this work, we attempted to synthesize homoeriodictyol by transferring one methyl group of S-adenosyl-l-methionine (SAM) to eriodictyol using flavone 3'-O-methyltransferase ROMT-9, which was produced by recombinant Yarrowia lipolytica. Specifically, the ROMT-9 gene from rice was synthesized and cloned into the multi-copy integrative vector pINA1297, and was further expressed in Y. lipolytica with a growth phase-dependent constitutive promoter hp4d. The highest ROMT-9 activity reached 5.53U/L after 4 days of culture in shake flask. The optimal pH and temperature of the purified ROMT-9 were 8.0 and 37°C, respectively. The purified enzyme was stable up to 40°C, and retained more than 80% of its maximal activity between pH 6.5 and 9.0. The recombinant ROMT-9 did not require Mg(2+) for catalysis, while was completely inhibited in the presence of 5mM Zn(2+), Cu(2+), Ba(2+), Al(3+), or Ni(2+). The purified ROMT-9 was used to synthesize homoeriodictyol, and the maximal transformation ratio reached 52.4% at 16h under the following conditions: eriodictyol 0.2g/L, ROMT-9 0.16g/L, SAM 0.2g/L, CH3OH 6% (v/v), temperature 37°C, and pH 8.0. This work provides an alternative strategy for efficient synthesis of homoeriodictyol and compared to the traditional plant extraction or chemical synthesis, the biotransformation approach generates less environmental pollution and has a great potential for the sustainable production of homoeriodictyol. PMID:23906843

Liu, Qingtao; Liu, Long; Zhou, Jingwen; Shin, Hyun-Dong; Chen, Rachel R; Madzak, Catherine; Li, Jianghua; Du, Guocheng; Chen, Jian

2013-07-29

340

Transforming giants.  

PubMed

Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big. PMID:18271317

Kanter, Rosabeth Moss

2008-01-01

341

Evaluate and characterize mechanisms controlling transport, fate, and effects of army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of hexachloroethane obscurant smokes  

SciTech Connect

The terrestrial transport, chemical fate, and ecological effects of hexachloroethane (HC) smoke were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on exposure scenarios, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of HC smoke/obscurants is establishing the importance of environmental parameters such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and two soil types. HC aerosols were generated in a controlled atmosphere wind tunnel by combustion of hexachloroethane mixtures prepared to simulate normal pot burn rates and conditions. The aerosol was characterized and used to expose plant, soil, and other test systems. Particle sizes of airborne HC ranged from 1.3 to 2.1 {mu}m mass median aerodynamic diameter (MMAD), and particle size was affected by relative humidity over a range of 20% to 85%. Air concentrations employed ranged from 130 to 680 mg/m{sup 3}, depending on exposure scenario. Chlorocarbon concentrations within smokes, deposition rates for plant and soil surfaces, and persistence were determined. The fate of principal inorganic species (Zn, Al, and Cl) in a range of soils was assessed.

Cataldo, D.A.; Ligotke, M.W.; Bolton, H. Jr.; Fellows, R.J.; Van Voris, P.; McVeety, B.D.; Li, Shu-mei W.; McFadden, K.M.

1989-09-01

342

Martensitic transformation in zirconia  

Microsoft Academic Search

Main characteristics of martensitic transformations in metals and alloys ; are described, and available data on the monoclinic-tetragonal transformation in ; ZrOâ are critically evaluated. Kinetics, thermal hysteresis, tetragonal -- ; cubic transformation, metastable high-temperature phases, and pressure and ; irradiationinduced transformation are discussed. Transformation in HfOâ is ; also briefly examined. (9 tables, 22 figures, 108 references) (DLC);

E. C. Subbarao; H. S. Maiti; K. K. Srivastava

1974-01-01

343

Biocompatible, pH-sensitive AB2 Miktoarm Polymer-Based Polymersomes: Preparation, Characterization, and Acidic pH-Activated Nanostructural Transformation  

PubMed Central

Motivated by the limitations of liposomal drug delivery systems, we designed a novel histidine-based AB2-miktoarm polymer (mPEG-b-(polyHis)2) equipped with a phospholipid-mimic structure, low cytotoxicity, and pH-sensitivity. Using “core-first” click chemistry and ring-opening polymerization, mPEG2kDa-b-(polyHis29kDa)2 was successfully synthesized with a narrow molecular weight distribution (1.14). In borate buffer (pH 9), the miktoarm polymer self-assembled to form a nano-sized polymersome with a hydrodynamic radius of 70.2 nm and a very narrow size polydispersity (0.05). At 4.2 µmol/mg polymer, mPEG2kDa-b-(polyHis29kDa)2 strongly buffered against acidification in the endolysosomal pH range and exhibited low cytotoxicity on a 5 d exposure. Below pH 7.4 the polymersome transitioned to cylindrical micelles, spherical micelles, and finally unimers as the pH was decreased. The pH-induced structural transition of mPEG2kDa-b-(polyHis29kDa)2 nanostructures may be caused by the increasing hydrophilic weight fraction of mPEG2kDa-b-(polyHis29kDa)2 and can help to disrupt the endosomal membrane through proton buffering and membrane fusion of mPEG2kDa-b-(polyHis29kDa)2. In addition, a hydrophilic model dye, 5(6)-carboxyfluorescein encapsulated into the aqueous lumen of the polymersome showed a slow, sustained release at pH 7.4 but greatly accelerated release below pH 6.8, indicating a desirable pH sensitivity of the system in the range of endosomal pH. Therefore, this polymersome that is based on a biocompatible histidine-based miktoarm polymer and undergoes acid-induced transformations could serve as a drug delivery vehicle for chemical and biological drugs.

Yin, Haiqing; Kang, Han Chang; Huh, Kang Moo; Bae, You Han

2012-01-01

344

Synthesis, structure characterization, and reversible transformation of a cobalt salt of a dilacunary ?-Keggin silicotungstate and sandwich-type di- and tetracobalt-containing silicotungstate dimers.  

PubMed

A cobalt salt of a ?-Keggin dilacunary silicotungstate, {CoL5}2[?-SiW10O34L2] [Co-SiW10; L = N,N-dimethylformamide (DMF) or H2O], could be synthesized by the cation-exchange reaction of TBA4[?-H4SiW10O36] (TBA = tetra-n-butylammonium) with 2 equiv of Co(NO3)2 with respect to TBA4[?-H4SiW10O36] in a mixed solvent of DMF and acetone (97% yield). Each Co-SiW10 was linked by water molecules via a hydrogen-bonding network. Besides Co-SiW10, various kinds of isostructural M-SiW10 could be synthesized via the same procedure as that for Co-SiW10 (M = Mn(2+), Fe(2+), Ni(2+), Cu(2+), Zn(2+), and Cd(2+)). By the reaction of Co-SiW10 with 1 equiv of TBA6[?-H2SiW10O36] in acetone, a silicotungstate dimer pillared by two cobalt cations with a significantly slipped dimer configuration, TBA6[Co2(?-H3SiW10O36)2]·3H2O (Co2), could be synthesized. By the reaction of Co-SiW10 with 3 equiv of TBAOH in acetone, a tetracobalt-containing sandwich-type silicotungstate, TBA6[{Co(H2O)}2(?3-OH)2{Co(H2O)2}2(?-H2SiW10O36)2]·5H2O (Co4), could be synthesized. Compound Co4 possessed the tetracobalt-oxygen core, [{Co(H2O)}2(?3-OH)2{Co(H2O)2}2](6+), identical with those of previously reported Weakley-type sandwich polyoxometalates, [Co4(H2O)2(XM9O34)2](n-) (X = P(5+), Si(4+), Ge(4+), As(5+) or V(5+); M = Mo(6+) or W(6+)). The reversible transformation between these three compounds (Co-SiW10 ? Co2, Co-SiW10 ? Co4, and Co2 ? Co4) took place by the addition and/or subtraction of required components in appropriate solvents, affording the desired products in high yields (71-93% yields). PMID:23834162

Kikukawa, Yuji; Suzuki, Kosuke; Yamaguchi, Kazuya; Mizuno, Noritaka

2013-07-08

345

Multiangle Multiscale Characterization of Seismic Reflection Data.  

National Technical Information Service (NTIS)

Contents: Introduction; Transformations and Multiscale Analysis; Characterization of Acoustic Data; Characterization of Velocity Contrast Functions; Processing and Characterization of Walk-Away VSP Data; Characterization of Shallow Data and CPT Data; The ...

J. C. Goudswaard

2001-01-01

346

Elements of Defense Transformation.  

National Technical Information Service (NTIS)

This document is intended to provide an understanding of the key elements of defense transformation. To that end, this brochure seeks to answer some fundamental questions about defense transformation. What is defense transformation and what is its scope. ...

2004-01-01

347

Mechanism of drug resistance, characterization of plasmid-borne determinants and transformation study in P. aeruginosa from burn and ICU units-its susceptibility pattern.  

PubMed

The transfer of drug resistance between hospital pathogens has led to alarming increase of multidrug resistant strains imposing therapeutic challenges. These resistant isolates harbor various mechanisms to counteract the drugs administered and have been reported to deliver these factors to sensitive strains in hostile environment. The present study aimed to screen for multidrug resistant Pseudomonas aeruginosa strains for the production of extended-spectrum ?-lactamases, metallo-?-lactamases, AmpC ?-lactamase, drug efflux phenotypes and co-transfer the resistance for cephalosporin and other non-beta lactam antibiotics in CaCl2 treated drug sensitive E. coli strains. From the 87 samples processed about 23 isolates of P. aeruginosa were ESBL and MBL positive, 5 (20%) were found to be AmpC ?-lactamase producers, efflux mechanism was observed in 8 isolates, 15 isolates had MIC of 16 ?g/ml. A putative efflux mechanism was observed in 8 out of 23 isolates that showed decrease in the MIC of meropenem with reserpine. The plasmid profile was characterized for all the common isolates obtained from burn and ICU units. About 69.66% of E. coli recombinants scored positive for both beta lactam and non-beta lactam antibiotics is due to co transfer of resistant plasmid obtained from P. aeruginosa. PMID:22980776

Shanthi, J; Pazhanimurugan, R; Gopikrishnan, V; Balagurunathan, R

2012-09-11

348

Natural and anthropogenic impacts on biogeochemical cycle in Yangtze River basin: Source, transformation and fate of dissolved organic matter (DOM) characterized by 3-D fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

Inland waters play an important role in the global carbon cycle as reactors for DOM cycling, transformation and transportation. With large amounts of terrestrial DOM, the Yangtze River is vital for coastal environment and ecosystem. In the context of climate change, it's critical to evaluate both hydrodynamic conditions and increasing human activities' impacts on biogeochemical cycle of DOM in Yangtze River across different climatic and hydrologic regions which are poorly understood. What's more, the hydrologic condition changes caused by the Three Gorges Dam (TGD, world's largest power station in terms of installed capacity) have recently proven to be a partition factor for fluvial particle. However, it's still an enigma for dissolved matter cycle. To address those issues, this study applies EEMs combined with bulk characteristics, chlorophyll and absorption spectrum in an attempt to assess characteristics and dynamics of DOM in Yangtze River. It's a novel optical approach that could 'see' molecular structure of DOM without the limits of time-consuming and laborious molecular measurements. Combined with parallel factor analysis, 5 individual fluorescent components have been identified: 3 humic-like (H1, H2, H3) and 2 protein-like components (P1, P2). With typical bioavailability and photo-reactivity, these components suggest different sources and dynamics. On the whole, both DOC and the sum of all 5 components (? Fluo) increased remarkably from the upper reach especially to the Three Gorge Dam and thereafter remained constant (R2between DOC and - Fluo: 0.92). The protein-like components (- P) accounted for 1/4 of - Fluo with apparently weak correlations with DOC and chlorophyll, which implied that the DOM is not dominated by autochthonous production, especially for the upper reach with high concentration of total suspended matter. As for Humic-like component, increasing H1 and DOC in the TGD reservoir area implied impacts from human activities there with intercept of sewage rather than an enabling environment for degradation. While in the lower reach where H3(Ex/Em:250/450~485nm) was accumulated, the other components (H1, H2) and a350 (absorption coefficient at 350nm) seemed to be degraded faster than H3 indicating that DOM might be subjected to selective biological and photochemical degradation processes, combined with remarkably higher Sr (absorption coefficient slope ratio, indicator of the degradation degree and aromatic property) in the lower reach after TGD, these facts suggests that the contrasting hydrology before and after TGD has led to a more significant composition differences and selective degradation of DOM. In case of any biased views, we conducted both dark and light incubations which showed consistency with the conclusion above. Besides, a comparison of Yangtze River and the other large rivers shows that the EEMs and a350 vary with land use, latitude and human activities, which verified their potential to trace the source and fate of fluvial DOM, even for different regions and water masses. Such knowledge on compositional differences of DOM resulting from variations in DOM sources and local environmental conditions (different photo-/bio-reactivity associated re-mineralization potential) during fluvial transport, would undoubtedly assist in predicting the consequences of global change and its relationship to global carbon cycling.

Gan, Shuchai; Wu, Ying; Bao, Hongyan; Zhang, Jing

2013-04-01

349

Power transformer handbook  

SciTech Connect

This book is a practical guide to transformer installation, use and maintenance. It examines the transformer from the customer's point of view, to familiarise them with installation and maintenance requirements, summarises the progress being made in transformer engineering and examines cost considerations. It discusses the following contents: Recent advances; Voltage reductions; Capitalisation of losses; Parallel operations; Cooling; Overloads; Operating limits of transformers and autotransformers; Protection; Installation conditions; Ventilation of enclosures; Noise limitation; Tests; The measurement of partial discharges; Maintenance; Liquid dielectrics; Overcurrents in transformers; Overvoltages; MV/LV transformers; Furnace transformers; and The transformer and the saving of energy.

Hochart, B.

1987-01-01

350

Borylene-based functionalization of iron-alkynyl-?-complexes and stepwise reversible metal-boryl-to-borirene transformation: synthesis, characterization, and density functional theory studies.  

PubMed

Thermally induced chemoselective borylene transfer from [(OC)(5)Mo=BN(SiMe(3))(2)] (2a) to the carbon-carbon triple bond of an iron dicarbonyl alkynyl complex [(?(5)-C(5)Me(5))Fe(CO)(2)C?CPh] (3) led to the isolation of an iron aminoborirene complex [(?(5)-C(5)Me(5))(OC)(2)Fe{?-BN(SiMe(3))(2)C=C}Ph] (4) in satisfactory yield. Room temperature photolysis of 4 resulted in an unprecedented rearrangement and a concurrent decarbonylation, affording the novel C(2) side-on coordinated iron boryl complex [(?(5)-C(5)Me(5))(OC)FeBN(SiMe(3))(2)(?(2)-CC)Ph] (5). Carbonylation of 5 under CO atmosphere at ambient temperature yielded [(?(5)-C(5)Me(5))(OC)(2)FeBN(SiMe(3))(2)CCPh] (6), which is an isomer of 4. Decarbonylation of 6 at 80 °C led to 5, which could be upon introduction of CO gas further converted into 4 under same conditions. Reaction of 5 with PMe(3) at 80 °C yielded the phosphane complex [(?(5)-C(5)Me(5))(OC)(PMe(3))Fe{?-BN(SiMe(3))(2)C=C}Ph] (7). All above-mentioned iron complexes 4-7 were isolated as air and moisture sensitive crystalline solids in good yields and have been fully characterized in solution and by X-ray crystallography. Quantum chemical calculations using density functional theory (DFT) have been carried out to understand the mechanisms of the experimentally observed reactions and to analyze the bonding situation in the molecules 4-7. PMID:20712372

Braunschweig, Holger; Ye, Qing; Radacki, Krzysztof; Brenner, Peter; Frenking, Gernot; De, Susmita

2010-08-16

351

Hardware-software partitioning and pipelined scheduling of transformative applications  

Microsoft Academic Search

Transformative applications are computation inten- sive applications characterized by iterative dataflow behavior. Typical examples are image processing applications like JPEG, MPEG, etc. The performance of embedded hardware-software systems that implement transformative applications can be maximized by obtaining a pipelined design. We present a tool for hardware-software partitioning and pipelined scheduling of transformative applications. The tool uses iterative partitioning and pipelined

Karam S. Chatha; Ranga Vemuri

2002-01-01

352

Transforming DNA Uptake Gene Orthologs Do Not Mediate Spontaneous Plasmid Transformation in Escherichia coli  

Microsoft Academic Search

Spontaneous plasmid transformation of Escherichia coli occurs on nutrient-containing agar plates. E. coli has also been reported to use double-stranded DNA (dsDNA) as a carbon source. The mechanism(s) of entry of exogenous dsDNA that allows plasmid establishment or the use of DNA as a nutrient remain(s) unknown. To further characterize plasmid transformation, we first documented the stimulation of transformation by

Dongchang Sun; Xuewu Zhang; Lingyu Wang; Marc Prudhomme; Zhixiong Xie; Bernard Martin; Jean-Pierre Claverys

2009-01-01

353

Characterization of triplex RNA poly[rU]· poly[rA]· poly[rU] adsorbed on silver colloids by Fourier transform surface enhanced Raman scattering and scanning tunneling microscopy  

NASA Astrophysics Data System (ADS)

Fourier transform surface enhanced Raman scattering (SERS) spectroscopy has been used to characterize triplex RNA poly[rU] · poly[rA] · poly[rU] adsorbed on silver colloid using an Nd:YAG laser as an excitation source. In this case, SERS spectra of high quality are recordable in a relatively short time. Compared to the FT-Raman spectrum of the triplex in solid, two distinct SERS bands centered at 835 and 819 cm-1 indicate that the helical structure of the triplex RNA in the proximity of the colloidal silver surfaces is well preserved. From UV-vis spectroscopy, the aggregation state of original silver colloids might not be distinctly altered after the triplex RNA was added up to 1 × 10-5 M. Moreover, scanning tunneling microscopy (STM) observations of the triplex-silver colloid complex also clearly reveal that the aggregation state of the silver colloids is changed from original dispersed particles to predominantly ordered adsorption along the phosphate backbone of the triplex with some aggregation, indicating that the microstructural changes of the silver surfaces play an important role in the SERS effect.

Fang, Ye; Bai, Chunli; Wang, Ting; Tang, You-Qi

1995-08-01

354

Characterization of large-scale fluctuations and short-term variability of Seine river daily streamflow (France) over the period 1950-2008 by empirical mode decomposition and the Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

Daily Seine river flow from 1950 to 2008 was analyzed using Hilbert-Huang Tranform (HHT). For the last ten years, this method which combines the so-called Empirical Mode Decomposition (EMD) multiresolution analysis and the Hilbert transform has proven its efficiency for the analysis of transient oscillatory signals, although the mathematical definition of the EMD is not totally established yet. HHT also provides an interesting alternative to other time-frequency or time-scale analysis of non-stationary signals, the most famous of which being wavelet-based approaches. In this application of HHT to the analysis of the hydrological variability of the Seine river, we seek to characterize the interannual patterns of daily flow, differenciate them from the short-term dynamics and eventually interpret them in the context of regional climate regime fluctuations. In this aim, HHT is also applied to the North-Atlantic Oscillation (NAO) through the annual winter-months NAO index time series. For both hydrological and climatic signals, dominant variability scales are extracted and their temporal variations analyzed by determination of the intantaneous frequency of each component. When compared to previous ones obtained from continuous wavelet transform (CWT) on the same data, HHT results highlighted the same scales and somewhat the same internal components for each signal. However, HHT allowed the identification and extraction of much more similar features during the 1950-2008 period (e.g., around 7-yr, between NAO and Seine flow than what was obtained from CWT, which comes to say that variability scales in flow likely to originate from climatic regime fluctuations were much properly identified in river flow. In addition, a more accurate determination of singularities in the natural processes analyzed were authorized by HHT compared to CWT, in which case the time-frequency resolution partly depends on the basic properties of the filter (i.e., the reference wavelet chosen initially). Compared to CWT or even to discrete wavelet multiresolution analysis, HHT is auto-adaptive, non-parametric, allows an orthogonal decomposition of the signal analyzed and provides a more accurate estimation of changing variability scales across time for highly transient signals.

Massei, N.; Fournier, M.

2010-12-01

355

Transforming the Way We Teach Function Transformations  

ERIC Educational Resources Information Center

|In this article, the authors discuss "function," a well-defined rule that relates inputs to outputs. They have found that by using the input-output definition of "function," they can examine transformations of functions simply by looking at changes to input or output and the respective changes to the graph. Applying transformations to the input…

Faulkenberry, Eileen Durand; Faulkenberry, Thomas J.

2010-01-01

356

Bainitelike transformations in some oxide ceramics  

NASA Astrophysics Data System (ADS)

The authors show two examples of “bainitelike” transformations in some oxide ceramics. A bainitelike transformation means that a shear (martensitic) mechanism is controlled by, or together with, ionic diffusion in the lattice as well as the case of lower bainite in steel. The first example is a tetragonal-to-monoclinic transformation in ZrO2-Y2O3 ceramics, where the bainitelike transformation must be characterized by (1) the increase in concentration of oxygen vacancies caused by the substitution of Zr4+ ions by Y3+ ions, (2) a fairly high mobility of oxygen ions through their vacancies, and (3) the formation of clusters composed of oxygen vacancies and oxygen ions. The second case is an inverse spinel to corundum structural change observed in ? Fe2O3 to ? Fe2O3, in which the bainitelike transformation may be explained by cooperative movements of oxygen and ferric ions, which are sandwiched between oxygen layers.

Nakanishi, N.; Shigematsu, T.; Furukawa, T.; Machida, N.

1994-12-01

357

Decoding modulation of the neuromuscular transform  

PubMed Central

When modulators of neuromuscular function alter the motor neuron spike patterns that elicit muscle contractions, it is predicted that they will also retune correspondingly the connecting processes of the neuromuscular transform. Here we confirm this prediction by analyzing data from the cardiac neuromuscular system of the blue crab. We apply a method that decodes the contraction response to the spike pattern in terms of three elementary building-block functions that completely characterize the neuromuscular transform. This method allows us to dissociate modulator-induced changes in the neuromuscular transform from changes in the spike pattern in the normally operating, essentially unperturbed neuromuscular system.

Stern, Estee; Fort, Timothy J.; Miller, Mark W.; Peskin, Charles S.; Brezina, Vladimir

2009-01-01

358

Transformations of W-type entangled states  

NASA Astrophysics Data System (ADS)

The transformations of W-type entangled states by using local operations assisted with classical communication are investigated. For this purpose, a parametrization of the W-type states which remains invariant under local unitary transformations is proposed and a complete characterization of the local operations carried out by a single party is given. These are used for deriving the necessary and sufficient conditions for deterministic transformations. A convenient upper bound for the maximum probability of distillation of arbitrary target states is also found.

K?nta?, S.; Turgut, S.

2010-09-01

359

Evaluate and characterize mechanisms controlling transport, fate and effects of Army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of red phosphorus-butyl rubber and white phosphorus obscurant smokes: Final report  

SciTech Connect

An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus (red phosphorus-butyl rubber (RP/BR)) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke/obscurant is currently proceeding. The objective is to characterize the effects of smokes and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of representative of soils of those sites; and (3) soil microbiological communities. The influence and interactions of smoke/obscurant concentration, relative humidity (25%, 60%, 90% and simulated rain) and wind speed of 0.22 to 4.45 m/s by smoke is assessed. Five plant species and four soils were exposed to both single and repeated doses of RP/BR smokes in the Pacific Northwest Laboratory ''P-3'' rated recirculating environmental wind tunnel. Detailed results for RP/BR and limited results for WP are presented. Toxicity symptoms for plants exposed for 2, 4, 6, and 8 hours to concentrations of RP/BR ranging from 200 mg/m/sup 3/ included leaf tip burn, leaf curl, leaf abscission and drop, floral abortion, chlorosis, neucrotic spotting, wilting, desiccation and dieback. Grass and bushbean were the most sensitive. The intensity and duration of these effects varied. Soils effects data suggest that there is an increase in the mobility of selected trace elements after exposure; however, this effect appears to be ameliorated with time. Soil microbial community effects show a reduction in the production of nitrate after soil is exposed to RP/BR smoke. Most of the plant, soil and soil microbial effects are transient in nature and are somewhat less intense resulting from repeated exposures; however, there is evidence that some of these environmental impacts may be persistent. 43 refs., 44 figs., 67 tabs.

Van Voris, P.; Ligotke, M.W.; McFadden, K.M.; Li, S.M.W.; Thomas, B.L.; Cataldo, D.A.; Garland, T.R.; Fredrickson, J.K.; Bean, R.M.; Carlile, D.W.

1987-10-01

360

Johnson Transformation System Revisited.  

National Technical Information Service (NTIS)

Some results on the Johnson transformation system are obtained which can enhance applications of this system in multivariate Monte Carlo studies. The primary contribution is that the mean vector and the covariance matrix in the transformed population can ...

M. E. Johnson J. S. Ramberg

1977-01-01

361

On the Watson Transformation.  

National Technical Information Service (NTIS)

The Watson transformation occurs in the problem of diffraction of electromagnetic waves by a perfectly conducting sphere. The series arising from a Watson transformation involves a set of complex valued functions which satisfy the orthogonality relations ...

E. Fischer

1966-01-01

362

Transformational Leadership in Wartime.  

National Technical Information Service (NTIS)

The intent of this paper is to examine three case studies of wartime transformation, analyze common factors leading to success, and suggest what kind of leadership the Army requires in its current effort to transform.

S. Eden

2004-01-01

363

DNA Transformation, Continued  

NSDL National Science Digital Library

DNA transformation is a naturally occurring but rare event in which DNA can be transferred into bacteria. In 1970, Morton Mandel and Akiko Higa discovered a way to make E. coli more 'competent' for transforming foreign DNA. Their calcium chloride method is widely used today to obtain high-efficiency transforming cells. This animation from Cold Spring Harbor Laboratory's Dolan DNA Learning Center presents the second part of explaining DNA transformation through a series of illustrations of the processes involved.

2012-03-14

364

Discrete radon transform  

Microsoft Academic Search

This paper describes the discrete Radon transform (DRT) and the exact inversion algorithm for it. Similar to the discrete Fourier transform (DFT), the DRT is defined for periodic vector-sequences and studied as a transform in its own right. Casting the forward transform as a matrix-vector multiplication, the key observation is that the matrix-although very large-has a block-circulant structure. This observation

GREGORY BEYLKIN

1987-01-01

365

The inverse loop transform  

Microsoft Academic Search

The loop transform in quantum gauge field theory can be recognized as the Fourier transform (or characteristic functional) of a measure on the space of generalized connections modulo gauge transformations. Since this space is a compact Hausdorff space, conversely, we know from the Riesz-Markov theorem that every positive linear functional on the space of continuous functions thereon qualifies as the

Thomas Thiemann; Max Planck

1998-01-01

366

Identifying Unknown Transformations  

NSDL National Science Digital Library

In this task, students apply their understanding of translations, rotations, and reflections to determine what transformation has been applied to a shape by comparing it to its image. The site has a brief description of the different kinds of transformations and an interactive applet with three challenges allowing students to determine which transformation is occurring.

2000-01-01

367

Model transformations in MT  

Microsoft Academic Search

Model transformations are recognised as a vital aspect of Model Driven Development, but current approaches cover only a small part of the possible spectrum. In this paper I present the MT model transformation which shows how a QVT-like language can be extended with novel pattern matching constructs, how tracing information can be automatically constructed and visualized, and how the transformed

Laurence Tratt

2007-01-01

368

Transformations - Composition (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore compositions of two transformations (among sliding, flipping and turning) both informally and within a coordinate system. Students select and compose shapes and manipulate the transformations to see the effect on a transformed image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

369

Revised transmission line model for electromagnetic characterization of metasurfaces  

NASA Astrophysics Data System (ADS)

We have revised the transmission line model with the purpose of simplifying the electromagnetic characterization of metasurfaces with both electric and magnetic responses. The revised model is an efficient tool for the case when a metasurface is located on top of a finite-thickness substrate or inside a finite-thickness slab. We have derived analytical expressions for the grid series impedance and shunt admittance of a substrated metasurface. The presented theory is illustrated by a numerical example of an array consisting of Mie-resonant silicon nanospheres. We have retrieved individual polarizabilities of a single sphere in a uniform host medium and compared them with the predictions of classical Mie theory. Further, we have studied a more practical case when the array of Si spheres is located on top of a finite-thickness glass substrate.

Albooyeh, M.; Ra'di, Y.; Adil, M. Q.; Simovski, C. R.

2013-08-01

370

Invertible Darboux Transformations  

NASA Astrophysics Data System (ADS)

For operators of many different kinds it has been proved that (generalized) Darboux transformations can be built using so called Wronskian formulae. Such Darboux transformations are not invertible in the sense that the corresponding mappings of the operator kernels are not invertible. The only known invertible ones were Laplace transformations (and their compositions), which are special cases of Darboux transformations for hyperbolic bivariate operators of order 2. In the present paper we find a criteria for a bivariate linear partial differential operator of an arbitrary order d to have an invertible Darboux transformation. We show that Wronkian formulae may fail in some cases, and find sufficient conditions for such formulae to work.

Shemyakova, Ekaterina

2013-01-01

371

Frequency analysis of DC tolerant current transformers  

NASA Astrophysics Data System (ADS)

This article deals with wide frequency range behaviour of DC tolerant current transformers that are usually used in modern static energy meters. In this application current transformers must comply with European and International Standards in their accuracy and DC tolerance. Therefore, the linear DC tolerant current transformers and double core current transformers are used in this field. More details about the problems of these particular types of transformers can be found in our previous works. Although these transformers are designed mainly for power distribution network frequency (50/60 Hz), it can be interesting to understand their behaviour in wider frequency range. Based on this knowledge the new generations of energy meters with measuring quality of electric energy will be produced. This solution brings better measurement of consumption of nonlinear loads or measurement of non-sinusoidal voltage and current sources such as solar cells or fuel cells. The determination of actual power consumption in such energy meters is done using particular harmonics component of current and voltage. We measured the phase and ratio errors that are the most important parameters of current transformers, to characterize several samples of current transformers of both types.

Mlejnek, P.; Kaspar, P.

2013-09-01

372

Measurements of Reactive Gaseous Rocket Injector Admittances  

Microsoft Academic Search

This paper describes the results of an experimental study that was concerned with the quantitative determination of the capabilities of the combustion processes associated with coaxial gaseous propellant rocket injectors to drive combustor pressure oscillations. The data, obtained by employing the modified impedance tube technique with compressed air as the oxidizer and acetylene gas as the fuel, describe the frequency

B. A. JANARDAN; B. R. DANIEL; W. A. BELL; B. T. ZINN

1979-01-01

373

Microbial transformation of 5-episinuleptolide.  

PubMed

5-episinuleptolide (1) is an abundant norcembranolide diterpene isolated from several species of the soft coral genus Sinularia. Biocatalytic transformation studies of 1 using Streptomyces lavendulea ATCC 8664 resulted in the isolation and characterization of two new metabolites 2 and 3. Compound 2, 6alpha-hydroxy-5-episinuleptolide was produced via a stereoselective reduction of 1 and was further metabolized into compound 3 which has a 3,8-bicylized cembranoid skeleton. The structures and configurations of the metabolites were determined by spectroscopic and X-ray crystallographic analyses. PMID:17409543

Kamel, Haidy Nasr; Fronczek, Frank Rolf; Khalifa, Sherief Ibrahim; Slattery, Marc

2007-04-01

374

The genesis of carbon-supported Fe-Mn and K-Fe-Mn catalysts from stoichiometric metal carbonyl clusters I. Characterization by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)  

SciTech Connect

The thermal decomposition of Fe{sub 3}(CO){sub 12}, NEt{sub 4}(Fe{sub 2}Mn(CO){sub 12}), Mn{sub 2}(CO){sub 10}, K(HFe{sub 3}(CO){sub 11}), and K(Fe{sub 2}Mn(CO){sub 12}) has been studied for the first time by dispersing these clusters on an oxygen-free carbon surface and monitoring their behavior by diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS). The Fe{sub 3}(CO){sub 12} decomposed to Fe(CO){sub 5} in either He or H{sub 2}, while Mn{sub 2}(CO){sub 10} decarbonylated without the formation of any stable intermediate clusters in either gas. The NEt{sub 4}(Fe{sub 2}Mn(CO){sub 12}) clusters decomposed with no formation of other stable carbonyl products in He, but in H{sub 2} they formed Mn{sub 2}(CO){sub 10} and (HFe{sub 4}(CO){sub 13}){sup {minus}} species. Similarly, the decomposition of K(Fe{sub 2}Mn(CO){sub 12}) in He produced no detectable intermediates, but under H{sub 2} it led to the formation of these same two intermediate clusters, while K(HFe{sub 3}(CO){sub 11}) yielded (HFe{sub 4}(CO){sub 13}){sup {minus}}. First-order rate constants of decomposition were determined for each cluster, compared to literature k{sub 1} values for nucleophilic substitution reactions in solution, and found to be similar to substitution rate constants for Fe{sub 3}(CO){sub 12} and Mn{sub 2}(CO){sub 10} but higher than those for Fe(CO){sub 5}. The rate-determining step in either the substitution or the decomposition reaction appears to be the removal of the first CO ligand in Fe{sub 3}(CO){sub 12}, but with Mn{sub 2}(CO){sub 10} it is Mn-Mn bond scission. The activation energies of decomposition were 18-21 kcal/mol for Fe{sub 3}(CO){sub 12} and 32-40 kcal/mol for Mn{sub 2}(CO){sub 10}, while those for the decomposition products gave intermediate values. This study represents a portion of the first successful application of an IR spectroscopic technique to characterize carbon-supported metal catalysts. 120 refs.

Venter, J.J.; Chen, A.; Vannice, M.A. (Pennsylvania State Univ., University Park (USA))

1989-05-01

375

Phase Transformation in Cast Superaustenitic Stainless Steels  

SciTech Connect

Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.

Nathaniel Steven Lee Phillips

2006-12-12

376

Semantics of Database Transformations  

Microsoft Academic Search

. Database transformations arise in many different settings includingdatabase integration, evolution of database systems, and implementing user viewsand data-entry tools. This paper surveys approaches that have been taken to problemsin these settings, assesses their strengths and weaknesses, and develops requirementson a formal model for specifying and implementing database transformations.We also consider the problem of insuring the correctness of database transformations.In

Peter Buneman; Susan B. Davidson; Anthony Kosky

1995-01-01

377

Continuous curvelet transform  

Microsoft Academic Search

We discuss a Continuous Curvelet Transform (CCT), a transform f??f(a,b,?) of functions f(x1,x2) on R2 into a transform domain with continuous scale a>0, location b?R2, and orientation ??[0,2?). Here ?f(a,b,?)=?f,?ab?? projects f onto analyzing elements called curvelets?ab? which are smooth and of rapid decay away from an a by a rectangle with minor axis pointing in direction ?. We call

Emmanuel J. Candès; David L. Donoho

2005-01-01

378

The Transformation of Open Source Software  

Microsoft Academic Search

A frequent characterization of open source software is the somewhat outdated, mythical one of a collective of supremely talented software hackers freely volunteering their services to produce uniformly high-quality software. I contend that the open source software phenomenon has metamorphosed into a more mainstream and commercially viable form, which I label as OSS 2.0. I illustrate this transformation using a

Brian Fitzgerald

2006-01-01

379

Nonlinear transformer model for circuit simulation  

Microsoft Academic Search

A transformer model which consists of a nonlinear core with hysteresis and multiple windings is described as implemented in DSPICE. In contrast to previous implementations, the nonlinear behavior of the new model is described by continuous piecewise-hyperbolic functions characterized by three parameters. These parameters are the same as parameters previously published in the literature. A loop-traversing algorithm has been implemented

John H. Chan; Andrei Vladimirescu; Xiao-chun Gao; Peter Liebmann; John Valainis

1991-01-01

380

LOCAL LINEAR TRANSFORMS FOR TEXTURE MEASUREMENTS  

Microsoft Academic Search

The Nth order probability density function for pixels in a restricted neighborhood may be characterized by a set of N histograms (or some corresponding moments) computed along appropriately chosen axes. The projections on those axes are obtained from a local linear transform of the local neighborhood vector. This approach is closely related to filter bank analysis methods and gives a

Michael UNSER

1986-01-01

381

Program Transformation in HATS  

SciTech Connect

HATS is a general purpose syntax derivation tree based transformation system in which transformation sequences are described in special purpose language. A powerful feature of this language is that unification is an explicit operation. By making unification explicit, an elegant framework arises in which to express complex application conditions which in turn enables refined control strategies to be realized. This paper gives an overview of HATS, focusing especially on the framework provided by the transformation language and its potential with respect to control and general purpose transformation.

Winter, V.L.

1999-02-24

382

Phase Transformation Kinetics: Advanced Modeling Strategies  

NASA Astrophysics Data System (ADS)

Phase transformations in the solid state are often heterogeneous and can be described by concurring modes of nucleation, growth, and impingement. The classical Johnson-Mehl-Avrami-Kolmogorov-(JMAK-) model, although offering an easy-to-use description of the transformation kinetics, is limited to very specific cases of the transformation modes. Instead, a generalized modular model of phase transformation kinetics can be proposed that provides a flexible formalism adaptable to various modes of nucleation, growth, and impingement. Due to its large versatility, the modular model approach can be easily applied for characterization of phase transformation kinetics beyond the scope of classical JMAK(-type) modeling. Three different strategies recently employed for such advanced modeling are presented: (I) deliberate variation of the nucleation mode upon crystallization of an Fe-Ni-B metallic glass in order to determine separate activation energies for nucleation and growth, (II) incorporation of specific, dedicated modes for nucleation and growth kinetics for the allotropic hcp-fcc transformation in cobalt introducing driving-force-dependent rates of transformation, and (III) implementation of quantitative microstructural data for the description of the precipitation kinetics in a supersaturated CuCo alloy.

Rheingans, B.; Mittemeijer, E. J.

2013-09-01

383

Characterization and Modeling of Pattern Ground Shield and Silicon-Substrate Effects on Radio-Frequency Monolithic Bifilar Transformers for Ultra-Wide Band Radio-Frequency Integrated Circuit Applications  

NASA Astrophysics Data System (ADS)

In this paper, an analysis of the effects of pattern-ground-shield (PGS) and silicon-substrate on the performances of RF monolithic bifilar transformers are demonstrated. It was found that high-quality-factor and low-power-loss transformers can be obtained if the optimized PGS (OPGS) of polysilicon is adopted and the complementary metal-oxide-semiconductor (CMOS)-process compatible backside inductively-coupled-plasma (ICP) deep trench technology is used to selectively remove the silicon underneath the transformers completely. OPGS means that the redundant PGS of a traditional complete PGS (CPGS), which is right below the spiral metal lines of the transformer, is removed for the purpose of reducing the large parasitic capacitance. The results show that, if the OPGS was adopted and the backside ICP etching was done, a 253.6% (from 3.79 to 13.4) increase in Q-factor, a 14% (from 0.7 to 0.798) increase in magnetic-coupling factor (kIm), a 51.1% (from 0.55 to 0.831) increase in maximum available power gain (GAmax), and a 1.79 dB (from 2.597 to 0.807) reduction in minimum noise factor (NFmin) were achieved at 8 GHz for a bifilar transformer with an overall dimension of 230× 215 ?m2.

Lin, Yo-Sheng; Chen, Chi-Chen; Liang, Hsiao-Bin; Wang, Tao; Lu, Shey-Shi

2007-01-01

384

Application of wavelet packet transform to compressing Raman spectra data  

Microsoft Academic Search

The Wavelet transform has been established with the Fourier transform as a data-processing method in analytical fields. The main fields of application are related to de-noising, compression, variable reduction, and signal suppression. Raman spectroscopy (RS) is characterized by the frequency excursion that can show the information of molecule. Every substance has its own feature Raman spectroscopy, which can analyze the

Chen Chen; Fei Peng; Qinghua Cheng; Dahai Xu

2008-01-01

385

Understanding Rigid Geometric Transformations: Jeff's Learning Path for Translation  

ERIC Educational Resources Information Center

|This article describes the development of knowledge and understanding of translations of Jeff, a prospective elementary teacher, during a teaching experiment that also included other rigid transformations. His initial conceptions of translations and other rigid transformations were characterized as undefined motions of a single object. He…

Yanik, Huseyin Bahadir; Flores, Alfinio

2009-01-01

386

A naturalness-preserving transform for image coding and reconstruction  

Microsoft Academic Search

We have developed a new image transform that possesses some unusual properties that may be useful for some special applications; especially for those instances in which the communications must pass through channels whose quality and characteristics are unpredictable due to nonstationary noise processes or jamming. We present an example of a use for the new transform that can be characterized

R. Yarlagadda; J. Hershey

1985-01-01

387

Martensitic nature of {delta} {yields} {gamma} allotropic transformation in plutonium  

SciTech Connect

Isothermal and isoplethal studies using differential scanning calorimetry have been conducted to characterize the allotropic transformations of plutonium. The {delta}-{gamma} transformation (upon cooling) was observed to have a classic martensitic nature. The work described herein is the first quantitative study of this phenomena in plutonium.

Lopez, P.C.; Cost, J.R.; Axler, K.M.

1996-09-01

388

Observability analysis of strapdown inertial navigation system using Lyapunov transformation  

Microsoft Academic Search

In this paper, the observability and the degree of observability for stationary SDINS error are analyzed. The use of the Lyapunov transformation is proposed for transforming the conventional SDINS error model and the sufficient conditions for the observability of SDINS error model are analytically derived. A complete characterization for the degree of observability during two position alignments is presented which

Dohyoung Chung; Chan Gook Park; Jang Gyu Lee

1996-01-01

389

Imaging and transforming transmission through inhomogeneous media with revolution symmetry  

Microsoft Academic Search

We study the paraxial imaging and transforming transmission through an inhomogeneous medium with spatial revolution symmetry obtaining the image and transform conditions. The medium is characterized by a transmittance function at the output plane similar to the conventional lens transmittance function.

C. Gomez-Reino; M. V. Perez; E. Larrea

1982-01-01

390

Deployment & Market Transformation (Brochure)  

SciTech Connect

NREL's deployment and market transformation (D and MT) activities encompass the laboratory's full range of technologies, which span the energy efficiency and renewable energy spectrum. NREL staff educates partners on how they can advance sustainable energy applications and also provides clients with best practices for reducing barriers to innovation and market transformation.

Not Available

2012-04-01

391

Why No Transformation.  

National Technical Information Service (NTIS)

Given the enthusiasm for transformation, why does the Pentagon hew to a modernization plan that will leave the military on the near side of the coming transformational divide, prepared to address old challenges far better than those now emerging. There is...

J. A. Krepinevich

2000-01-01

392

Phase Transformations in Materials  

Microsoft Academic Search

For all kinds of materials, phase transformations show common phenomena and mechanisms, and often turn a material, for example metals, multiphase alloys, ceramics or composites, into its technological useful form. The physics and thermodynamics of a transformation from the solid to liquid state or from one crystal form to another are therefore essential for creating high-performance materials. This handbook covers

Gernot Kostorz

2001-01-01

393

The Fourier Transform  

Microsoft Academic Search

To calculate a transform, just listen. The ear automatically performs the calculation, which the intellect can execute only after years of mathematical education. The ear formulates a transform by converting sound-the waves of pressure traveling through time and the atmosphere-into a spectrum, a description of the sound as a series of volumes at distinct pitches. The brain turns this information

Ronald N. Bracewell

1989-01-01

394

Genetic Transformation of Bacteria.  

ERIC Educational Resources Information Center

|An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)|

Moss, Robert.

1991-01-01

395

Transformation optics and metamaterials  

NASA Astrophysics Data System (ADS)

Underpinned by the advent of metamaterials, transformation optics offers great versatility for controlling electromagnetic waves to create materials with specially designed properties. Here we review the potential of transformation optics to create functionalities in which the optical properties can be designed almost at will. This approach can be used to engineer various optical illusion effects, such as the invisibility cloak.

Chen, Huanyang; Chan, C. T.; Sheng, Ping

2010-05-01

396

A Transformation Called "Twist"  

ERIC Educational Resources Information Center

|The transformations found in secondary mathematics curriculum are typically limited to stretches and translations (e.g., ACARA, 2010). Advanced students may find the transformation, twist, to be of further interest. As most available resources are written for professional-level readers, this article is intended to be an introduction accessible to…

Hwang, Daniel

2010-01-01

397

Advanced Hough Transform Implementations.  

National Technical Information Service (NTIS)

In the Hough transform, a feature in an input space I votes for parameters in a transform space P with which it is compatible. It it also uses negative votes to vote against parameters with which it is incompatible, background bias and inherent noise in P...

C. M. Brown M. B. Curtiss D. B. Sher

1983-01-01

398

Civilian Human Resource Transformation.  

National Technical Information Service (NTIS)

Transformation to meet warfighting requirements of the 21st Century is one of the highest priorities in the U.S. Army today. Army Chief of Staff General Eric K. Shineseki's overall Army vision cites three priorities: people, readiness, and transformation,...

L. S. Phillips

2003-01-01

399

Model transformations in Converge  

Microsoft Academic Search

Model transformations are currently the focus of much interest and research due to the OMG's QVT initiative. Current proposals for model transformation lan- guages can be divided into two main camps: those taking a 'declarative' approach, and those opting for an 'imperative' approach. In this paper we detail an imper- ative, meta-circular, object orientated, pattern matching programming language Converge which

Laurence Tratt; Tony Clark

2003-01-01

400

Biochemical transformation of coals  

DOEpatents

A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed. 7 figs.

Lin, M.S.; Premuzic, E.T.

1999-03-23

401

Biochemical transformation of coals  

DOEpatents

A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed.

Lin, Mow S. (Rocky Point, NY); Premuzic, Eugene T. (East Moriches, NY)

1999-03-23

402

Genetic Transformation in Citrus  

PubMed Central

Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species.

Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Aka Kacar, Yildiz; Yalcin Mendi, Yesim

2013-01-01

403

The martensitic transformation in ceramics — its role in transformation toughening  

Microsoft Academic Search

This paper reviews the current knowledge and understanding of martensitic transformations in ceramics — the tetragonal to monoclinic transformation in zirconia in particular. This martensitic transformation is the key to transformation toughening in zirconia ceramics. A very considerable body of experimental data on the characteristics of this transformation is now available. In addition, theoretical predictions can be made using the phenomenological

Patrick M. Kelly; L. R. Francis Rose

2002-01-01

404

Transforming activity of DNA of chemically transformed and normal cells  

Microsoft Academic Search

DNA fragments of chemically transformed and normal avian and murine cells induce transformation of NIH 3T3 mouse cells with low efficiencies. High molecular weight DNAs of cells transformed by DNA fragments induce transformation with high efficiencies in secondary transfection assays. It thus seems that endogenous transforming genes of uninfected cells can be activated and efficiently transmitted by transfection. These results

Geoffrey M. Cooper; Sharon Okenquist; Lauren Silverman

1980-01-01

405

Advances in the Natural transform  

NASA Astrophysics Data System (ADS)

The literature review of the Natural transform and the existing definitions and connections to the Laplace and Sumudu transforms are discussed in this communication. Along with the complex inverse Natural transform and Heaviside's expansion formula, the relation of Bessel's function to Natural transform (and hence Laplace and Sumudu transforms) are defined.

Belgacem, F. B. M.; Silambarasan, R.

2012-11-01

406

Highly efficient sorghum transformation.  

PubMed

A highly efficient microprojectile transformation system for sorghum (Sorghum bicolor L.) has been developed by using immature embryos (IEs) of inbred line Tx430. Co-bombardment was performed with the neomycin phosphotransferase II (nptII) gene and the green fluorescent protein (gfp) gene, both under the control of the maize ubiquitin1 (ubi1) promoter. After optimization of both tissue culture media and parameters of microprojectile transformation, 25 independent transgenic events were obtained from 121 bombarded IEs. The average transformation frequency (the total number of independent transgenic events divided by the total number of bombarded IEs) was 20.7% in three independent experiments. Transgenic events were confirmed by both PCR screening and Southern hybridization of genomic DNA from primary transgenics (T?). More than 90% of transformants were fertile and displayed normal morphology in a containment glasshouse. Co-transformation rate of the nptII and gfp genes was 72% in these experiments. The segregation of nptII and gfp in T? progenies was observed utilizing fluorescence microscopy and geneticin selection of seedlings indicating both were inherited in the T? generation. The transformation procedure, from initiating IEs to planting putative transgenic plantlets in the glasshouse, was completed within 11-16 weeks, and was approximately threefold more efficient than the previously reported best sorghum transformation system. PMID:22234443

Liu, Guoquan; Godwin, Ian D

2012-01-11

407

Transforming activity of DNA of chemically transformed and normal cells  

NASA Astrophysics Data System (ADS)

DNA fragments of chemically transformed and normal avian and murine cells induce transformation of NIH 3T3 mouse cells with low efficiencies. High molecular weight DNAs of cells transformed by DNA fragments induce transformation with high efficiencies in secondary transfection assays. It thus seems that endogenous transforming genes of uninfected cells can be activated and efficiently transmitted by transfection. These results are consistent with the hypothesis that normal cells contain genes that are capable of inducing transformation if expressed at abnormal levels.

Cooper, Geoffrey M.; Okenquist, Sharon; Silverman, Lauren

1980-04-01

408

Biolistics Transformation of Wheat  

NASA Astrophysics Data System (ADS)

We present a complete, step-by-step guide to the production of transformed wheat plants using a particle bombardment device to deliver plasmid DNA into immature embryos and the regeneration of transgenic plants via somatic embryogenesis. Currently, this is the most commonly used method for transforming wheat and it offers some advantages. However, it will be interesting to see whether this position is challenged as facile methods are developed for delivering DNA by Agrobacterium tumefaciens or by the production of transformants via a germ-line process (see other chapters in this book).

Sparks, Caroline A.; Jones, Huw D.

409

Polynomial transformation for MRI feature extraction  

NASA Astrophysics Data System (ADS)

We present a non-linear (polynomial) transformation to minimize scattering of data points around normal tissue clusters in a normalized MRI feature space, in which normal tissues are clustered around pre-specified target positions. This transformation is motivated by non-linear relationship between MRI pixel intensities and intrinsic tissue parameters (e.g., T1, T2, PD). To determine scattering amount, we use ratio of summation of within-class distances fro clusters to summation of their between-class distances. We find the transformation by minimizing the scattering amount. Next, we generate a 3D visualization of the MRI feature space and define regions of interest (ROI's) on clusters seen for normal and abnormal tissues. We use these ROI's to estimate signature vectors (cluster centers). Finally, we use the signature vectors for segmenting and characterizing tissues. We used simulation, phantom, and brain MRI to evaluate the polynomial transformation and compare it to the linear transformation. In all studies, we were able to identify clusters for normal and abnormal tissues and segment the images. Compared to the linear method, the non-linear approach yields enhanced clustering properties and better separation of normal and abnormal tissues. ON the other hand, the linear transformation is more appropriate than the non-linear method for capturing partial volume information.

Soltanian-Zadeh, Hamid; Kharrat, Mahmood; Peck, Donald J.

2001-07-01

410

Pulse Transformer Design Study.  

National Technical Information Service (NTIS)

The design of a compact, lightweight, high average power, air-core pulse transformer to satisfy the electrical and physical requirements of a developmental power conditioning system is presented. (Author)

H. Aslin P. Chao

1975-01-01

411

Fourier Transform Mass Spectrometry  

PubMed Central

This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook.

Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

2011-01-01

412

The Inverse Laplace Transform  

NSDL National Science Digital Library

Created by Lang Moore for the Connected Curriculum Project, the purpose of this module is to illustrate the use of the residue theorem in calculating inverse laplace transforms. This is one of many learning modules hosted by Duke University.

Moore, Lang

2010-06-14

413

Enzymatic Transformations of Lignin.  

National Technical Information Service (NTIS)

Research efforts in the areas of biochemical engineering, enzymology, and lignin chemistry and an analysis relating to enzymatic transformations of lignin are reported. Biochemical engineering investigations of microbial metabolism on lignin were studied....

P. L. Hall

1979-01-01

414

Proof in Transformation Geometry  

ERIC Educational Resources Information Center

|The first of three articles showing how inductively-obtained results in transformation geometry may be organized into a deductive system. This article discusses two approaches to enlargement (dilatation), one using coordinates and the other using synthetic methods. (MM)|

Bell, A. W.

1971-01-01

415

Transformation of Rhodosporidium toruloides.  

PubMed

Rhodosporidium toruloides protoplasts could be transformed, in the presence of polyethylene glycol (PEG), at frequencies of approx. 1 X 10(3) transformants/micrograms of DNA. The plasmid used, pHG2, which contains the phenylalanine ammonia-lyase (PAL)-coding gene (PAL) of R. toruloides, could replicate as an unstable plasmid in the yeast, or could integrate at the PAL locus to give stable transformants. Plasmids that function in R. toruloides were constructed using either the PAL gene or LEU2 gene of Saccharomyces cerevisiae as dominant selectable markers. R. toruloides transformed with pHG8, which contains both genes, coinherited the two markers. It is also shown that the 2mu replicon of S. cerevisiae does not function in R. toruloides; neither is the PAL gene expressed in S. cerevisiae. PMID:3000875

Tully, M; Gilbert, H J

1985-01-01

416

A Classical Science Transformed.  

ERIC Educational Resources Information Center

Describes how satellites and other tools of space technology have transformed classical geodesy into the science of space geodynamics. The establishment and the activities of the French Center for Geodynamic and Astronomical Research Studies (CERGA) are also included. (HM)

Kovalevsky, Jean

1979-01-01

417

Integral Transformational Coaching  

Microsoft Academic Search

\\u000a In Chap. 12, Keizer and Nandram present the concept of Integral Transformational Coaching based on the concept of Flow and its effects on work performance. Integral Transformational Coaching is a method that prevents\\u000a and cures unhealthy stress and burnout. They draw on some tried and tested spiritually based insights from the schools of\\u000a mindfulness, coaching, and mental fitness. Their model

Wim A. J. Keizer; Sharda S. Nandram

2009-01-01

418

Transformation of Yeast  

Microsoft Academic Search

A stable leu2- yeast strain has been transformed to LEU2+ by using a chimeric ColE1 plasmid carrying the yeast leu2 gene. We have used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced. These studies show

Albert Hinnen; James B. Hicks; Gerald R. Fink

1978-01-01

419

Earth limb radiance transformation  

Microsoft Academic Search

A mathematical transformation is derived for predicting the upsounding (down-welling) infrared atmospheric radiance from measurements of the Earth limb radiance profile. The transformation is derived by writing the equation or radiactive transfer for each viewing geometry in terms of the altitude dependent volume emission function J(r) and then eliminating J(r) from the equations to define the upsounding profile directly as

S. J. Young

1981-01-01

420

Selection of Transformed Plants  

NASA Astrophysics Data System (ADS)

The low frequency and randomness of transgene integration into host cells, combined with the significant challenges of recovering whole plants from those rare events, makes the use of selectable marker genes routine in plant transformation experiments. For research applications that are unlikely to be grown in the field, strong herbicide- or antibiotic resistance is commonly used. Here we use genes conferring resistance to glufosinate herbicides as an example of a selectable marker in wheat transformation by either Agrobacterium or biolistics.

Jones, Huw D.; Sparks, Caroline A.

421

Super fast Fourier transform  

NASA Astrophysics Data System (ADS)

In this paper, we have developed the recursive fast orthogonal mapping algorithms based fast Fourier transforms. Particularly, we introduced a new fast Fourier transform algorithm with linear multiplicative complexity. The proposed algorithms not only reduces the multiplicative complexity, but also is comparable to the existing methods such as Duhamel, Heideman, Burrus, Vetterli, Wang [11,15,16,19,21,27,28] in the total number of operations (arithmetic complexity, or the number of multiplications and additions).

Agaian, Sos S.; Caglayan, Okan

2006-02-01

422

Chemical transformation of yeast.  

PubMed

Transformation of chemically competent yeast cells is a method for introducing exogenous DNA into living cells. Typically, the DNA is either a plasmid carrying an autonomous replication sequence that allows for propagation or a linear piece of DNA to be integrated into the genome. The DNA usually also carries a marker that allows for selection of successfully transformed cells by plating on the appropriate selective media. PMID:24011057

Bergkessel, Megan; Guthrie, Christine

2013-01-01

423

Plant transformation technology  

Microsoft Academic Search

Plant transformation has its roots in the research on Agrobacterium that was being undertaken in the early 1980s. The last two decades have seen significant developments in plant transformation\\u000a technology, such that a large number of transgenic crop plants have now been released for commercial production. Advances\\u000a in the technology have been due to development of a range of Agrobacterium-mediated

Christine A. Newell

2000-01-01

424

Floral Transformation of Wheat  

NASA Astrophysics Data System (ADS)

A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

425

Innovative surface characterization techniques applied to immunosensor elaboration and test: Comparing the efficiency of Fourier transform–surface plasmon resonance, quartz crystal microbalance with dissipation measurements, and polarization modulation–reflection absorption infrared spectroscopy  

Microsoft Academic Search

Three sensitive and original transduction techniques have been used to monitor the immobilization of anti-rabbit immunoglobulins (anti-rIgGs) and the detection of rIgGs on gold transducers. Polarization modulation–reflection absorption infrared spectroscopy (PM–RAIRS), quartz crystal microbalance with dissipation measurements (QCM–D), and Fourier transform–surface plasmon resonance (FT–SPR) were combined to achieve the best sensitivity and a large dynamic range in the target detection

Souhir Boujday; Christophe Méthivier; Bruno Beccard; Claire-Marie Pradier

2009-01-01

426

Development of a new transformant selection system for Penicillium chrysogenum : isolation and characterization of the P. chrysogenum acetyl-coenzyme A synthetase gene ( facA ) and its use as a homologous selection marker  

Microsoft Academic Search

A new transformation system for the filamentous fungus Penicillium chrysogenum is described, based on the use of the homologous acetyl-coenzyme A synthetase (facA) gene as a selection marker. Acetate-non-utilizing (Fac-) strains of P. chrysogenum were obtained by positive selection for spontaneous resistance to fluoroacetate. Among these fac mutants putative facA strains were selected for a loss of acetyl-coenzyme A (CoA)

Robin J. Gouka; Wim van Hartingsveldt; Roel A. L. Bovenberg; Cora M. J. van Zeijl; Cees A. M. J. J. van den Hondel; Robert F. M. van Gorcom I

1993-01-01

427

Planar LTCC transformers for high voltage flyback converters.  

SciTech Connect

This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

2007-06-01

428

Electromagnetic potentials without gauge transformations  

NASA Astrophysics Data System (ADS)

In this paper, we show that the use of the Helmholtz theorem enables the derivation of uniquely determined electromagnetic potentials without the necessity of using gauge transformation. We show that the electromagnetic field comprises two components, one of which is characterized by instantaneous action at a distance, whereas the other propagates in retarded form with the velocity of light. In our attempt to show the superiority of the new proposed method to the standard one, we argue that the action-at-a-distance components cannot be considered as a drawback of our method, because the recommended procedure for eliminating the action at a distance in the Coulomb gauge leads to theoretical subtleties that allow us to say that the needed gauge transformation is not guaranteed. One of the theoretical consequences of this new definition is that, in addition to the electric E and magnetic B fields, the electromagnetic potentials are real physical quantities. We show that this property of the electromagnetic potentials in quantum mechanics is also a property of the electromagnetic potentials in classical electrodynamics.

Chubykalo, A.; Espinoza, A.; Alvarado Flores, R.

2011-07-01

429

How Political Science Became Modern: Racial Thought and the Transformation of the Discipline, 1880-1930  

ERIC Educational Resources Information Center

|This dissertation argues that changing ideas about race and engagement with race science were at the heart of a major transformation of political science in the 1920s, a transformation that I characterize as "becoming modern." This transformation was at once conceptual--visible in the basic categories and theoretical apparatus of the…

Blatt, Jessica

2009-01-01

430

Complete sequence analysis of transgene loci from plants transformed via microprojectile bombardment  

Microsoft Academic Search

A substantial literature exists characterizing transgene locus structure from plants transformed via Agrobacterium and direct DNA delivery. However, there is little comprehensive sequence analysis of transgene loci available, especially from plants transformed by direct delivery methods. The goal of this study was to completely sequence transgene loci from two oat lines transformed via microprojectile bombardment that were shown to have

I. Makarevitch; S. K. Svitashev; D. A. Somers

2003-01-01

431

The Speed of Light under the Generalized Transformations, Inertial Transformations, \\  

Microsoft Academic Search

Starting with Edwards' synchrony parameter dependent transformation equations in two space dimensions, transformation equations are derived for speeds. The obtained results are particularized to the case of the inertial (Tangherlini, Selleri) transformations and to the transformation equations that are the result of the \\

Bernhard Rothenstein

432

TRANSFORMATIVE LEARNING THEORY: LEARNING BY TRANSFORMING AND CHANGING  

Microsoft Academic Search

In this manuscript, Mezirow’s transformative learning theory is studied. In this context, the definition, dimensions of transformative learning, the roles of teachers and learners in transformative learning and its curricular scopes are analyzed. In the study held as analyses of the literature, the following results are reached: Transformative learning theory is formed with a synthesis of critical reflection and hermeneutics.

Burhan Akpinar

2010-01-01

433

Martensitic transformation in zirconia  

SciTech Connect

We investigate by atomic force microscopy (AFM) the surface relief resulting from martensitic tetragonal to monoclinic phase transformation induced by low temperature autoclave aging in ceria-stabilized zirconia. AFM appears as a very powerful tool to investigate martensite relief quantitatively and with a great precision. The crystallographic phenomenological theory is used to predict the expected relief induced by the transformation, for the particular case of lattice correspondence ABC1, where tetragonal c axis becomes the monoclinic c axis. A model for variants spatial arrangement for this lattice correspondence is proposed and validated by the experimental observations. An excellent agreement is found between the quantitative calculations outputs and the experimental measurements at nanometer scale yielded by AFM. All the observed features are explained fully quantitatively by the calculations, with discrepancies between calculations and quantitative experimental measurements within the measurements and calculations precision range. In particular, the crystallographic orientation of the transformed grains is determined from the local characteristics of transformation induced relief. It is finally demonstrated that the strain energy is the controlling factor of the surface transformation induced by low temperature autoclave treatments in this material.

Deville, Sylvain [Materials Science Department, National Institute of Applied Science (GEMPPM-INSA), Associate Research Unit 5510, Bat. B. Pascal, 20 av. A. Einstein, 69621 Villeurbanne Cedex (France)]. E-mail: sylvain.deville@insa-lyon.fr; Guenin, Gerard [Materials Science Department, National Institute of Applied Science (GEMPPM-INSA), Associate Research Unit 5510, Bat. B. Pascal, 20 av. A. Einstein, 69621 Villeurbanne Cedex (France); Chevalier, Jerome [Materials Science Department, National Institute of Applied Science (GEMPPM-INSA), Associate Research Unit 5510, Bat. B. Pascal, 20 av. A. Einstein, 69621 Villeurbanne Cedex (France)

2004-11-08

434

Building an evolution transformation library  

Microsoft Academic Search

We have been developing knowledge-based tools to support the evolutionary development of specifications. Evolution is accomplished by means of evolution transformations, which are meaning-changing transformations applied to formal specifications. A sizable library of evolution transformations has been developed for our specification language, Gist. This paper assesses the results of our previous work on evolution transformations. It then describes our current

W. Lewis Johnson; Martin S. Feather

1990-01-01

435

Developing skills in strategic transformation  

Microsoft Academic Search

This article considers strategic transformation and how organisations can learn to become better at strategically transforming themselves over time. Two case studies are considered, Marks & Spencer and Intel, and these provide two contrasting examples of how organisations can either be reactive or proactive in managing strategic transformation. The article argues that in order for strategic transformation to become an

Gary J. Stockport

2000-01-01

436

Value systems of transformational leaders  

Microsoft Academic Search

This study attempts to draw a value profile of a transformational leader – the leader who transforms people and organizations. It compares the terminal and instrumental value systems of leaders who are more transformational with those of leaders who are less transformational, using a sample of 95 pairs of leaders and subordinates of a non-profit organization in the United States.

Venkat R. Krishnan

2001-01-01

437

Shape transformation for polyhedral objects  

Microsoft Academic Search

Techniques that transform one two-dimensionaf image into another have gained widespread use m recent yeara. Extending these tech- niques to transform pairs of 3D objects, as opposed to 2D images of the objects, providea several advsntagea, including the ability to sn- imate the objects independently of the transformation. This paper presents an algorithm for computing such transformations. The al- gorithm

James R. Kent; Wayne E. Carlson; Richard E. Parent

1992-01-01

438

Phase transformations in uranium, plutonium, and neptunium  

Microsoft Academic Search

The actinide metals uranium and neptunium are characterized by three allotropes, and plutonium has six solid phases with two\\u000a of the allotropes having complex, low symmetry, crystal structures. Further, many phase changes in these metals are accompanied\\u000a by a large specific volume change and a large enthalpy change. Phase transformations in uranium and plutonium have been studied\\u000a extensively but very

J. J. Rechtien; R. D. Nelson

1973-01-01

439

Mineralogical transformations controlling acid mine drainage chemistry  

Microsoft Academic Search

The role of Fe(III) minerals in controlling acid mine drainage (AMD) chemistry was studied using samples from two AMD sites [Gum Boot (GB) and Fridays-2 (FR)] located in northern Pennsylvania. Chemical extractions, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to identify and characterize Fe(III) phases. The mineralogical analysis revealed schwertmannite and goethite

Tetyana Peretyazhko; John M. Zachara; Jean F. Boily; Yuanxian Xia; Paul L. Gassman; Bruce W. Arey; William D. Burgos

2009-01-01

440

Chemical Transformations of Phyllocladane ( 13-Kaurane) Diterpenoids  

Microsoft Academic Search

Earlier phytochemical work on Plectranthus ambiguus (Lamiaceae) afforded a series of tetracyclic phyllocladane-type ( 13-kaurane) diterpenoids (see 1a ± f). In the course of investigations concerning the reaction behavior of this rare natural-products, a new constituent of P. ambiguus was isolated, (2S,3R,16R)- phyllocladane-2,3,16,17-tetrol 2,3-diacetate (1g), and another eighteen new phyllocladanes were prepared by chemical transformations and characterized. The main constituent

Gui Liu; Ralph Mller; Peter Redi

441

The genesis of carbon-supported Fe-Mn and K-Fe-Mn catalysts from stoichiometric metal carbonyl clusters I. Characterization by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)  

Microsoft Academic Search

The thermal decomposition of Feâ(CO)ââ, NEtâ(FeâMn(CO)ââ), Mnâ(CO)ââ, K(HFeâ(CO)ââ), and K(FeâMn(CO)ââ) has been studied for the first time by dispersing these clusters on an oxygen-free carbon surface and monitoring their behavior by diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS). The Feâ(CO)ââ decomposed to Fe(CO)â in either He or Hâ, while Mnâ(CO)ââ decarbonylated without the formation of any stable intermediate clusters in

J. J. Venter; A. Chen; M. A. Vannice

1989-01-01

442

Transformation optics for plasmonics.  

PubMed

A new strategy to control the flow of surface plasmon polaritons at metallic surfaces is presented. It is based on the application of the concept of transformation optics to devise the optical parameters of the dielectric medium placed on top of the metal surface. We describe the general methodology for the design of transformation optical devices for surface plasmons and analyze, for proof-of-principle purposes, three representative examples with different functionalities: a beam shifter, a cylindrical cloak, and a ground-plane cloak. PMID:20465271

Huidobro, Paloma A; Nesterov, Maxim L; Martín-Moreno, Luis; García-Vidal, Francisco J

2010-06-01

443

Course Transformation: Strategies  

NSDL National Science Digital Library

The past few decades have seen an explosion of research-based physics curricula and teaching methods that replace traditional didactic instruction with more interactive, student-centered teaching methods. Teachers who use these strategies can transform their students from passive acceptors of knowledge to active investigators who are deeply engaged in their own education. And not only will students learn more, but they may come out with a more positive attitude towards physics. This site gives examples of which modifications to make, as well as of other institutions which have already undergone course transformation.

2008-05-20

444

Microbial transformation of (+)-adrenosterone.  

PubMed

The microbial transformation of (+)-adrenosterone (1) by Cephalosporium aphidicola afforded three metabolites identified as androsta-1,4-diene-3,11,17-trione (2), 17beta-h