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1

Synthesis and spectroscopic characterization of complexes of Cr(III), Cr(VI), Cu(III), Zn(II), Mo(VI), Pd(II), Ag(III), Au(III) and W(VI) with telluric acid  

NASA Astrophysics Data System (ADS)

New preparative methods are reported for telluric acid complexes, Na5[Cr(TeO4(OH)2)2(H2O)2], Na6[Zn(TeO4(OH)2)2(H2O)2], Na6[Pd(TeO4(OH)2)2], Na5[M(TeO4(OH)2)2] (M(III) = Cu, Ag, Au) and KTeM6?O (M?(VI) = Cr, Mo, W). Their structures were characterized on the basis of spectroscopic, crystallographic, magnetic and thermal measurements. The deprotonation constants of telluric acid and the stability constants of the Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) complexes were determined by pH-metric measurements.

Butler, Ian S.; El-Sherbeny, Heba Allah M.; Kenawy, Ibrahim M.; Mostafa, Sahar I.

2013-03-01

2

The Effect of Small Islands of Telluric Currents.  

National Technical Information Service (NTIS)

The telluric current data of Macquarie Island show complete polarization of the induced electric field. This phenomenon can be explained by assuming that Macquarie Island is an insulator imbedded in the highly conducting sea with a uniform electric field ...

D. W. Swift E. M. Wescott

1964-01-01

3

Transformation of some hydroxy amino acids to other amino acids.  

PubMed

It has been observed that beta-hydroxy-alpha-amino acids are transformed into other amino acids, when heated in dilute solutions with phosphorous acid, phosphoric acid or their ammonium salts. It has been shown that as in the case of previously reported glycine-aldehyde reactions, glycine also reacts with acetone to give beta-hydroxyvaline under prebiologically feasible conditions. It is suggested, therefore, that the formation of beta-hydroxy-alpha-amino acids and their transformation to other amino acids may have been a pathway for the synthesis of amino acids under primitive earth conditions. PMID:1208100

Choughuley, A S; Subbaraman, A S; Kazi, Z A; Chadha, M S

1975-10-01

4

EMT - Empirical-mode-decomposition-based Magneto-Telluric Processing  

NASA Astrophysics Data System (ADS)

We present a new Magneto-Telluric (MT) data processing scheme based on an emerging non linear, non stationary time series analysis tool, called the Empirical Mode Decomposition (EMD) or Hilbert-Huang Transform (HHT), to transform data into a non-stationary frequency domain and a robust principal component regression to estimate the most likely MT transfer functions from the data with the 2-? confidence intervals computed by a bootstrap algorithm. Optionally, data quality can be controlled by a physical coherence and a signal power filter. MT sources are assumed to be quasi stationary and therefore a (windowed) Fourier Transform is often applied to transform the time series into the frequency domain in which Transfer Functions (TF) are defined between the electromagnetic field components. This assumption can break down in the presence of noise or when the sources are non stationary, and then TF estimates can become unreliable when obtained through a stationary transform like the Fourier transform. Our TF estimation scheme naturally deals with non stationarity without introducing artifacts and, therefore, potentially can distinguish quasi-stationary sources and non-stationary noise. In contrast to previous works on using HHT for MT processing, we argue the necessity of a multivariate EMD to model the MT problem physically correctly and highlight the resulting possibility to use instantaneous parameters as independent and identically distributed variables. Furthermore, we define a homogenization between data channels of frequency discrepancies due to non stationarity and noise. The TF estimation in the frequency domain bases on a robust principal component analysis in order to find two source polarizations. These two principal components are used as predictor to regress robustly the data channels within a bootstrap algorithm to estimate the Earth's Transfer function with 2-? confidence interval supplied by the measured data.The scheme can be used with and without aid by any number of remote reference stations. The performance of this scheme will be demonstrated on MT data and compared with BIRRP, a widely used MT processing software by Alan Chave.

Neukirch, M.; Garcia, X.

2012-04-01

5

The Detection and Measurement of Telluric Ozone from Stellar Spectra  

NASA Astrophysics Data System (ADS)

``One man's noise is another man's signal.'' Never has that (mis)quotation been more apt than in this instance, in which the annoying features of telluric origin, bypassed and avoided by the astronomer, need to be salvaged by the atmospheric scientist from data detritus. This paper describes the first phase of a project designed to determine telluric O3 column densities from historic stellar spectra, and demonstrates the validity of the concept by comparing the results with almost contemporary measurements made by satellite.

Griffin, R. Elizabeth

2005-08-01

6

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

7

Mineralogical transformations controlling acid mine drainage chemistry  

SciTech Connect

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 that schwertmannite and goethite were the principal Fe(III) phases in the sediments. Schwertmannite transformation occurred at the GB site where poorly-crystallized goethite rich in surface-bound sulfate was initially formed. In contrast, no schwertmannite transformation occurred at the FR site. The goethite in GB sediments had spherical morphology due to preservation of schwertmannite structure by adsorbed sulfate. Results of chemical extractions showed that poorly-crystallized goethite was subject to further crystallization accompanied by sulfate desorption. Changes in sulfate speciation preceded its desorption, with a conversion of bidentate- to monodentate-bound sulfate surface complexes. Laboratory sediment incubation experiments were conducted to evaluate the effect of mineral transformation on water chemistry. Incubation experiments were carried out with schwertmannite-containing sediments and AMD waters with different pH and chemical composition. The pH decreased to 1.9-2.2 in all suspensions and the concentrations of dissolved Fe and S increased significantly. Regardless of differences in the initial water composition, pH, Fe and S were similar in suspensions of the same sediment. XRD measurements revealed that schwertmannite transformed into goethite in GB and FR sediments during laboratory incubation. The incubation experiment demonstrated that schwertmannite transformation controlled AMD water chemistry during “closed system” laboratory contact.

Peretyazhko, Tetyana; Zachara, John M.; Boily, Jean F.; Xia, Yuanxian; Gassman, Paul L.; Arey, Bruce W.; Burgos, William D.

2009-05-30

8

Correcting METIS spectra for telluric absorption to maximize spectral fidelity  

NASA Astrophysics Data System (ADS)

METIS is a mid-infrared instrument proposed for the European Extremely Large Telescope. It is designed to provide imaging and spectroscopic capabilities in the 3 - 14 micron region up to a spectral resolution of 100000. One of the novel concepts of METIS is that of a high-resolution integral field spectrograph for a diffraction-limited mid-IR instrument. While this concept has many scientific and operational advantages over a long-slit spectrograph, one drawback is that the spectral resolution changes over the field of view. This has an impact on the procedures to correct for telluric absorption lines imprinted on the science spectra. They are a major obstacle in the quest to maximize spectral fidelity, the ability to distinguish a weak spectral feature from the continuum. The classical technique of division by a standard star spectrum, observed in a single IFS spaxel, cannot simply be applied to all spaxels, because the spectral resolution changes from spaxel to spaxel. Here we present and discuss possible techniques of telluric line correction of METIS IFS spectra, including the application of synthetic model spectra of telluric transmission, to maximize spectral fidelity.

Uttenthaler, Stefan; Pontoppidan, Klaus M.; Seifahrt, Andreas; Kendrew, Sarah; Blommaert, Joris A. D. L.; Pantin, Eric J.; Brandl, Bernhard R.; Molster, Frank J.; Venema, Lars; Lenzen, Rainer; Parr-Burman, Philip; Siebenmorgen, Ralf

2010-07-01

9

A Comparison of Telluric Current and Magnetic Field Observations in the Arctic Ocean  

Microsoft Academic Search

Simultaneous observations of the H and D components of the magnetic field and of two components of telluric current were made on Arctic drifting station Charlie during the winter of 1959-1960 and on station Arlis I in early 1961. The telluric current and mag- netometer data show a striking similarity. Spectral analysis showed the two types of data to have

Daniel W. Swift; Victor P. Hessler

1964-01-01

10

Fluid circulation in the active emerged Asal rift (east Africa, Djibouti) inferred from self-potential and Telluric–Telluric prospecting  

Microsoft Academic Search

In 1996 Self-Potential (SP) and Telluric–Telluric (TT) surveys were performed in the Asal rift, in the Republic of Djibouti, in order to study water circulation through the rift, from Ghoubbet Strait to Asal lake located 11km Northwest, and at the altitude of 155m below sea level. SP surveys reveal two main positive anomalies, several kilometres wide, up to 150mV in

M. Mlynarski; J Zlotnicki

2001-01-01

11

Syntheses, transformations and pharmaceutical applications of kynurenic acid derivatives.  

PubMed

The syntheses and transformations of 4-hydroxyquinoline-2-carboxylic acid, kynurenic acid, are reviewed, and special attention is paid to the pharmacological activities and pharmaceutical applications of its derivatives. PMID:19929784

Fülöp, F; Szatmári, I; Vámos, E; Zádori, D; Toldi, J; Vécsei, L

2009-01-01

12

Biological sulfuric acid transformation: Reactor design and process optimization  

Microsoft Academic Search

As an alternative to the current disposal technologies for waste sulfuric acid, a new combination of recycling processes was developed. The strong acid (H[sub 2]SO[sub 4]) is biologically converted with the weak acid (CH[sub 3]COOH) into two volatile weak acids (H[sub 2]S, H[sub 2]CO[sub 3]) by sulfate-reducing bacteria. The transformation is possible without prior neutralization of the sulfuric acid. The

Gerhard Stucki; R. A. Huerzeler; K. W. Hanselmann

1993-01-01

13

Transformations of tributyl phosphate in contact with acidic aqueous solutions  

SciTech Connect

Investigation of the transformations of tributyl phosphate in contact with fluoridesulfuric acid solutions be means of method /sup 19/F and /sup 31/P NMR spectroscopy and potentiometric titration shows that in the course of time it undergoes processes of hydrolysis and fluorination. In the extracts acid butyl phosphates and phosphoric acid together with products of their fluorination were found. The extent of the breakdown of tributyl phosphate depends on the time and the composition of the aqueous solutions.

Nikolaev, A.I.; Ignatov, M.E.; Shevyreva, E.V.; Zalkind, L.M.; Il'in, E.G.; Buslaev, Y.A.

1986-11-20

14

Ursolic acid, an antagonist for transforming growth factor (TGF)-?1  

Microsoft Academic Search

Transforming growth factor-? (TGF-?), a multifunctional cytokine which is involved in extracellular matrix modulation, has a major role in the pathogenesis and progression of fibrotic diseases. We now report the effects of ursolic acid on TGF-?1 receptor binding and TGF-?1-induced cellular functions in vitro. Ursolic acid inhibited [125I]-TGF-?1 receptor binding to Balb\\/c 3T3 mouse fibroblasts with an IC50 value of

Shigeru Murakami; Hajime Takashima; Mariko Sato-Watanabe; Sumi Chonan; Koji Yamamoto; Masako Saitoh; Shiuji Saito; Hiromitsu Yoshimura; Koko Sugawara; Junshan Yang; Nannan Gao; Xinggao Zhang

2004-01-01

15

Synthetic Transformations of Resin Acids. IX. Certain Derivatives of 12-Br-Dehydroabietic Acid.  

National Technical Information Service (NTIS)

The authors attempted to produce anologs of gibberellins - potential plant growth regulators - from 12-Br-dehydroabietic acid. As a result of the synthetic transformation of 12-Br-dehydroabietic acid, 12-Br-6,7-diketomethyl dehydroabietate, 6 Br-1,2,3,4,1...

M. I. Goryaev F. S. Sharipova L. K. Tikhonova L. A. Elchibekova E. B. Popova

1972-01-01

16

FTIR, Raman, and UV-Vis spectroscopic and DFT investigations of the structure of iron-lead-tellurate glasses.  

PubMed

In this work, the effects of iron ion intercalations on lead-tellurate glasses were investigated via FTIR, Raman and UV-Vis spectroscopies. This homogeneous glass system has compositions xFe(2)O(3)?(100-x)[4TeO(2)?PbO(2)], where x?=?0-60 mol%. The presented observations in these mechanisms show that the lead ions have a pronounced affinity towards [TeO(3)] structural units, resulting in the deformation of the Te-O-Te linkages, and leading to the intercalation of [PbO( n )] (n?=?3, 4) and [FeO( n )] (n?=?4, 6) entities in the [TeO(4)] chain network. The formation of negatively charged [FeO(4)](1-) structural units implies the attraction of Pb(2+) ions in order to compensate for this electrical charge. Upon increasing the Fe(2)O(3) content to 60 mol%, the network can accommodate an excess of oxygen through the formation of [FeO(6)] structural units and the conversion of [TeO(4)] into [TeO(3)] structural units. For even higher Fe(2)O(3) contents, Raman spectra indicate a greater degree of depolymerization of the vitreous network than FTIR spectra do. The bands due to the Pb-O bond vibrations are very strongly polarized and the [TeO(4)] structural units convert into [TeO(3)] units via an intermediate coordination stage termed "[TeO(3+1)]" structural units. Our UV-Vis spectroscopic data show two mechanisms: (i) the conversion of the Fe(3+) to Fe(2+) at the same time as the oxidation of Pb(2+) to Pb(+4) ions for samples with low Fe(2)O(3) contents; (ii) when the Fe(2)O(3) content is high (x???50 mol%), the Fe(2+) ions capture positive holes and are transferred to Fe(3+) ions through a photochemical reaction, while the Pb(2+) ions are formed by the reduction of Pb(4+) ions. DFT calculations show that the addition of Fe(2)O(3) to lead-tellurate glasses seems to break the axial Te-O bonds, and the [TeO(4)] structural units are gradually transformed into [TeO(3+1)]- and [TeO(3)]-type polyhedra. Analyzing these data further indicates a gradual conversion of the lead ions from covalent to ionic environment. There is then a charge transfer between the tri- and tetracoordinated tellurium atoms due to the capacity of the lead-tellurate network to form the appropriate coordination environments containing structural units of opposite charge, such as iron ions, [FeO(4)](1-). PMID:21174135

Rada, Simona; Dehelean, Adriana; Culea, Eugen

2010-12-21

17

Taxonomy of the Neisseriae: Deoxyribonucleic Acid Base Composition, Interspecific Transformation, and Deoxyribonucleic Acid Hybridization  

Microsoft Academic Search

Deoxyribonucleic acid (DNA) base composition, intergenic transformation efficiency, and DNA hybridization were used to determine the relatedness of a variety of established or proposed species of Neisseria and Branhamella. These studies indicated that these bacteria form three genetic groupings. Group I, comprised of N. meningitidis, N. gonorrhoeae, N. subflava, N. flava, N. perflava, N. sicca, N. mucosa, N. cinerea, N.

CAROLYN HOKE; NEYLAN A. VEDROS

1982-01-01

18

Iron Transformations Induced by an Acid-Tolerant Desulfosporosinus Species  

PubMed Central

The mineralogical transformations of Fe phases induced by an acid-tolerant, Fe(III)- and sulfate-reducing bacterium, Desulfosporosinus sp. strain GBSRB4.2 were evaluated under geochemical conditions associated with acid mine drainage-impacted systems (i.e., low pH and high Fe concentrations). X-ray powder diffractometry coupled with magnetic analysis by first-order reversal curve diagrams were used to evaluate mineral phases produced by GBSRB4.2 in media containing different ratios of Fe(II) and Fe(III). In medium containing Fe predominately in the +II oxidation state, ferrimagnetic, single-domain greigite (Fe3S4) was formed, but the addition of Fe(III) inhibited greigite formation. In media that contained abundant Fe(III) [as schwertmannite; Fe8O8(OH)6SO4 · nH2O], the activities of strain GBSRB4.2 enhanced the transformation of schwertmannite to goethite (?-FeOOH), due to the increased pH and Fe(II) concentrations that resulted from the activities of GBSRB4.2.

Bertel, Doug; Peck, John; Quick, Thomas J.

2012-01-01

19

Monomethylarsonous acid induces transformation of human bladder cells  

PubMed Central

Arsenic is a human bladder carcinogen. Arsenic is methylated to both monomethyl and dimethyl metabolites which have been detected in human urine. The trivalent methylated arsenicals are more toxic than inorganic arsenic. It is unknown if these trivalent methylated metabolites can directly cause malignant transformation in human cells. The goal of this study is determine if monomethylarsonous acid (MMAIII) can induce malignant transformation in a human bladder urothelial cell line. To address this goal, a non-tumorigenic human urothelial cell line (UROtsa) was continuously exposed to 0.05 ?M MMAIII for 52 weeks. Hyperproliferation was the first phenotypic change observed in exposed UROtsa (URO-MSC). After 12 weeks of exposure, doubling time had decreased from 42 h in unexposed control cells to 27 h in URO-MSC. Hyperproliferation continued to be a quality possessed by the URO-MSC cells after both 24 and 52 weeks of exposure to MMAIII, which had a 40–50% reduction in doubling time. Throughout the 52-week exposure, URO-MSC cells retained an epithelial morphology with subtle morphological differences from control cells. 24 weeks of MMAIII exposure was required to induce anchorage-independent growth as detected by colony formation in soft agar, a characteristic not found in UROtsa cells. To further substantiate that malignant transformation had occurred, URO-MSC cells were tested after 24 and 52 weeks of exposure to MMAIII for the ability to form tumors in SCID mice. Enhanced tumorigenicity in SCID mouse xenografts was observed after 52 weeks of treatment with MMAIII. These observations are the first demonstration of MMAIII-induced malignant transformation in a human bladder urothelial cell line and provide important evidence that MMAIII may be carcinogenic in human tissues.

Bredfeldt, Tiffany G.; Jagadish, Bhumasamudram; Eblin, Kylee E.; Mash, Eugene A.; Gandolfi, A. Jay

2010-01-01

20

Transformation of ginseng saponins to ginsenoside rh 2 by acids and human intestinal bacteria and biological activities of their transformants  

Microsoft Academic Search

When ginseng water extract was incubated at 60°C in acidic conditions, its protopanaxadiol ginsenosides were transformed to\\u000a ginsenoside Rg3 and ?20-ginsenoside Rg3. However, protopanaxadiol glycoside ginsenosides Rb1, Rb2 and Rc isolated from ginseng were mostly not transformed to ginsenoside Rg3 by the incubation in neutral condition. The transformation of these ginsenosides to ginsenoside Rg3 and ?20-ginsenoside Rg3 was increased by

Eun-Ah Bae; Myung Joo Han; Eun-Jin Kim; Dong-Hyun Kim

2004-01-01

21

Flow of electric currents of telluric origin in a long metal pipeline and their effect in relation to corrosion control  

SciTech Connect

To determine the effects of telluric currents on the corrosion of a 280-mile (450-km) steel pipeline in Kenya, Spencer and Partners, London, and the University of Nairobi, Kenya, estimated the extent to which these currents influence corrosion rates on the line, their effects on potential readings, and the possible beneficial effects of further sectioning the lines or installing blocking diodes. Difficulties experienced during the installation of cathodic protection pointed to the presence of stray currents, railway, or various d-c grounds near the pipeline. Data from time-calibrated recording meters and other test information showed that the stray currents correlated with telluric-current magnitudes associated with the sun's activity; sunspot storms were producing currents of up to 2A. Telluric currents substantially affected the accuracy of cathodic-protection tests. This experience validates the contention that coating perfection is helpful, especially in high-conductivity soil zones.

Barker, R.H.; Skinner, N.J.

1980-02-01

22

High efficiency transformation of intact yeast cells using single stranded nucleic acids as a carrier  

Microsoft Academic Search

A method, using LiAc to yield competent cells, is described that increased the efficiency of genetic transformation of intact cells of Saccharomyces cerevisiae to more than 1 × 105 transformants per microgram of vector DNA and to 1.5% transformants per viable cell. The use of single stranded, or heat denaturated double stranded, nucleic acids as carrier resulted in about a

Robert H. Schiestl; R. Daniel Gietz

1989-01-01

23

The planetary scale distribution of telluric currents and the effect of the equatorial electrojet: An investigation by canonical GDS  

Microsoft Academic Search

The planetary scale distribution of electrical currents in the Earth is still largely unknown. The role of the oceans for long period (hours to days) inducing electromagnetic fieldsBe of external origin has been investigated by several authors, while the role of telluric current channelling, from the planetary viewpoint, is still far from a satisfactory understanding. Canonical geomagnetic depth sounding (GDS)

G. P. Gregori; L. J. Lanzerotti; B. Alessandrini; G. Defranceschi; R. Cipollone

1987-01-01

24

Formation and transformation of amino acids and amino acid precursors by high-velocity impacts  

NASA Astrophysics Data System (ADS)

A wide variety of organic compounds have been found in extraterrestrial bodies such as comets and carbonaceous chondrites. It is plausible that these extraterrestrial bodies carried organic compounds such as amino acids or their precursors to the early Earth. It is claimed, however, that these extraterrestrial organics were destroyed during impacts to the Earth. We therefore examined possible transformation of amino acids and their precursors during high-velocity impacts by using a rail gun "HYPAC" in ISAS. Starting materials used in the impact experiments were (i) aqueous solution of glycine (10 mM or 1.0 M), and (ii) a mixture of ammonia, methanol and water. The target materials were sealed in stainless steel capsules, and shocked by impact with a polycarbonate projectile accelerated with "HYPAC" to the velocities of 2.5 - 7.0 km/s. A part of the products was acid-hydrolyzed. Both hydrolyzed an unhydrolyzed products were analyzed by mass spectrometry, high performance liquid chromatography and capillary electrophoresis and chromatography. When an aqueous solution containing ammonia, methanol and water was shocked by impact at the velocity of 6.4 km/s, a number of amino acids (e.g., serine and glycine) were detected after hydrolysis. The present results suggest that amino acid precursors could be formed during cometary impacts. When glycine solution was used as a starting material, about 40 % of glycine was recovered even after 6 km/s impact. Methylamine and ammonia, which are known as pyrolytic products of glycine, were detected, besides them, diketopiperazine and an unidentified product whose molecular weight was 134, were detected, while no glycine peptides were identified in them. It was shown that the impact processes resulted in the formation of amino acid condensates. Thermal stability of glycine precursor is comparable with glycine. The present results suggest that organic material could survive and/or formed during an impact process. Most of organic compounds in comets and carbonaceous chondrites were complex organic compounds. Laboratory simulations suggest that they contain precursors of amino acids. We are examining possible alteration of such complex precursors of amino acids by high-velocity impacts.

Kaneko, T.; Kobayashi, K.; Yamori, A.

25

Seismic and magneto-telluric imaging for geothermal exploration at Jemez pueblo in New Mexico  

SciTech Connect

A shallow geothermal reservoir in the Pueblo of Jemez in New Mexico may indicate a commercial-scale geothermal energy potential in the area. To explore the geothermal resource at Jemez Pueblo, seismic surveys are conducted along three lines for the purpose of imaging complex subsurface structures near the Indian Springs fault zone. A 3-D magneto-telluric (MT) survey is also carried out in the same area. Seismic and MT imaging can provide complementary information to reveal detailed geologic formation properties around the fault zones. The high-resolution seismic images will be used together with MT images, geologic mapping, and hydrogeochemistry, to explore the geothermal resource at Jemez Pueblo, and to determine whether a conunercial-scale geothermal resource exists for power generation or direct use applications after drilling and well testing.

Huang, Lianjie [Los Alamos National Laboratory; Albrecht, Michael [LOS ALAMOS GEOTHERMAL

2011-01-25

26

Control of growth by picolinic acid: Differential response of normal and transformed cells  

PubMed Central

Picolinic acid reversibly inhibits the growth of cultured cells. Fourteen other pyridine derivatives were ineffective or toxic. Untransformed normal rat kidney (NRK) cells are reversibly arrested in the G1 stage of the growth cycle as shown by cell counts, mitotic index, [3H]thymidine incorporation, and flow microfluorometry. Flow microfluorometry was used to monitor the effects of picolinic acid on numerous other cell lines. Normal cells are blocked in G1, whereas transformed cells show responses that are dependent upon the transforming virus and independent of species or origin of the cell line. Kirsten sarcoma virus-transformed cells are blocked in G1. Simian virus 40-transformed cells progress to a G2 block. Cells transformed by polyoma or Harvey sarcoma virus with Moloney virus coat have flow microfluorometry profiles that indicate blocks in both G1 and G2. Cells transformed with Moloney sarcoma virus are not blocked in a specific phase of the cell cycle. Picolinic acid does not change the levels of NAD+ plus NADH; however, the growth inhibition by picolinic acid is partially overcome by nicotinamide. These results suggest that picolinic acid interacts with a specific growth control mechanism that may involve NAD+ and that this control mechanism is altered by different transforming viruses in different manners. Images

Fernandez-Pol, J. A.; Bono, Vincent H.; Johnson, George S.

1977-01-01

27

Control of growth by picolinic acid: differential response of normal and transformed cells.  

PubMed

Picolinic acid reversibly inhibits the growth of cultured cells. Fourteen other pyridine derivatives were ineffective or toxic. Untransformed normal rat kidney (NRK) cells are reversibly arrested in the G(1) stage of the growth cycle as shown by cell counts, mitotic index, [(3)H]thymidine incorporation, and flow microfluorometry. Flow microfluorometry was used to monitor the effects of picolinic acid on numerous other cell lines. Normal cells are blocked in G(1), whereas transformed cells show responses that are dependent upon the transforming virus and independent of species or origin of the cell line. Kirsten sarcoma virus-transformed cells are blocked in G(1). Simian virus 40-transformed cells progress to a G(2) block. Cells transformed by polyoma or Harvey sarcoma virus with Moloney virus coat have flow microfluorometry profiles that indicate blocks in both G(1) and G(2). Cells transformed with Moloney sarcoma virus are not blocked in a specific phase of the cell cycle. Picolinic acid does not change the levels of NAD(+) plus NADH; however, the growth inhibition by picolinic acid is partially overcome by nicotinamide. These results suggest that picolinic acid interacts with a specific growth control mechanism that may involve NAD(+) and that this control mechanism is altered by different transforming viruses in different manners. PMID:197524

Fernandez-Pol, J A; Bono, V H; Johnson, G S

1977-07-01

28

Rapid abiotic transformation of nitrate in an acid forest soil  

Microsoft Academic Search

Nitrate immobilization into organic matter is thought to require catalysis by the enzymes of soil microorganisms. However, recent studies suggest that nitrate added to soil is immobilized rapidly and this process may include abiotic pathways. We amended living and sterilized soil with 15N-labeled nitrate and nitrite to investigate biotic and abiotic immobiliz- ation. We report rapid transformation of nitrate in

DAVID BRYAN DAIL; RIC A. DAVIDSON; JON CHOROVER

2001-01-01

29

Development of a New Environment-conscious Transformer Impregnated with Palm Fatty Acid Ester (PFAE)  

NASA Astrophysics Data System (ADS)

We have developed a new environment-conscious transformer impregnated with vegetable based insulating oil which called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. This means that a PFAE immersed transformer has better cooling efficiency and better insulating performance in paper-and-oil composite insulation systems, resulting in size reduction in comparison to conventional mineral oil immersed transformers. In this paper, insulating performance of lead to plane electrode models, cooling performance of a PFAE immersed transformer, and the result of analytical study of dissolved gas for abnormal diagnosis are described.

Hikosaka, Tomoyuki; Yamazaki, Akina; Hatta, Yasunori; Koide, Hidenobu; Kanoh, Takaaki; Suzuki, Takashi; Yamada, Junichi; Uemura, Shingo

30

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

31

Organic amendment effects on the transformation and fractionation of aluminum in acidic sandy soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study was attempted to evaluate the transformation of aluminum (Al) in an acidic sandy soil amended with composts (yard waste, yard + municipal waste, GreenEdge®, and synthetic humic acid), based on soil Al fractionation by single and sequential extraction. The compost amendment significantly i...

32

Modified zirconia solid acid catalysts for organic synthesis and transformations  

Microsoft Academic Search

A series of sulfate, molybdate and tungstate promoted ZrO2 catalysts were prepared by wet impregnation method. To incorporate these promoters to Zr(OH)4, sulfuric acid, ammonium heptamolybdate, and ammonium metatungstate were used as precursors, respectively. Further, a Pt promoted Mo-ZrO2 catalyst was also prepared separately by impregnating with hexachloroplatinic acid. The surface and bulk properties of various promoted ZrO2 catalysts were

Benjaram M. Reddy; Pavani M. Sreekanth; Vangala R. Reddy

2005-01-01

33

Polymorphic Phase Transformation in the 3-Bromo-trans-cinnamic Acid System  

NASA Astrophysics Data System (ADS)

3-Bromo-trans-cinnamic acid (3-BrCA) exists as two crystalline polymorphic forms (designated as ? and ? phases). A polymorphic phase transformation from the ? phase to the ? phase has been investigated using ex situ powder X-ray diffraction, in situ high-temperature optical microscopy, and differential scanning calorimetry. The transformation occurs at an observable rate at temperatures above about 100°C. A reverse transformation on subsequently cooling the ? phase is not observed. Thermodynamic aspects of the polymorphic 3-BrCA system are discussed, together with kinetic aspects of the transformation from the ? phase to the ? phase. The structural properties of the ? phase (reported previously) and the ? phase (determined in this work from single-crystal X-ray diffraction data) are in accord with the ?/?/? structural classification of trans-cinnamic acid derivatives.

Ahn, Shinbyoung; Harris, Kenneth D. M.; Kariuki, Benson M.; Zin, Dimple M. S.

2001-01-01

34

Selective Toxicity Induced by Picolinic Acid in Simian Virus 40- transformed Cells in Tissue Culture1  

Microsoft Academic Search

SUMMARY When cultured normal and SV40-transformed normal rat kidney and BALB\\/3T3 cells were exposed to picolinic acid, cell proliferation ceases. Most of the normal cells remained in a quiescent G, (G�) state and viable for prolonged periods of time. In contrast, SV40-transformed cells progressed to the S and G2phases of the cell cycle and remained viable only up to 90

J. A. Fernandez-Pol; George S. Johnson

35

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

36

Selective toxicity induced by picolinic acid in simian virus 40-transformed cells in tissue culture.  

PubMed

When cultured normal and SV40-transformed normal rat kidney and BALB/3T3 cells were exposed to picolinic acid, cell proliferation ceases. Most of the normal cells remained in a quiescent G1 (G0) state and viable for prolonged periods of time. In contrast, SV40-transformed cells progressed to the S and G2 phases of the cell cycle and remained viable only up to 90 to 120 hr. Then, most of the cells began to die. However, a very small fraction of the cell population (approximately 0.01 percent) developed into variants resistant to picolinic acid. Prevention of development of variants, and therefore destruction of all transformed cells, was obtained by addition of glycerol to picolinic acid-treated cells. Untransformed cells were unaffected by the same treatment. These results suggest that differential tumor toxicity should be feasible. PMID:200344

Fernandez-Pol, J A; Johnson, G S

1977-12-01

37

Chemical transformations of proteinogenic amino acids during their sublimation in the presence of silica  

NASA Astrophysics Data System (ADS)

Proteinogenic amino acids were sublimed in gram quantities in the presence of silica. High-performance liquid chromatographic and fast-atom-bombardment mass-spectrometric measurements showed that diketopiperazines (DKPs) were the main products of silica catalyzed thermal transformations in the case of aliphatic bifunctional amino acids. Intensive formation of products of decarboxylation, deamination and some other reactions was observed in the cases of trifunctional amino acids and phenylalanine. Possible mechanisms of reactions occured have been discussed. Principal possibility of ‘gas-solid-phase’ DKP synthesis has been demonstrated for bifunctional aliphatic amino acids.

Basiuk, Vladimir A.; Gromovoy, Taras Yu; Glukhoy, Alexandr M.; Golovaty, Vitaly G.

1991-05-01

38

Direct and efficient transformation of gaseous alkanes into carboxylic acids catalyzed by vanadium containing heteropolyacids  

Microsoft Academic Search

The vanadium containing heteropolyacids H4[PMo11VO40]×34H2O (HPA-1), H5[PMo10V2O40]×32H2O (HPA-2) and H6[PMo9V3O40]×34H2O (HPA-3) act as highly active catalysts for the direct transformation of light C1–C3 alkanes into the corresponding carboxylic acids in the presence of CO and in the K2S2O8\\/CF3COOH system. Propionic acid (ca. 70% yield), iso- and n-butyric acids (ca. 65% overall yield), and acetic acid (ca. 20%) are the major

Marina V. Kirillova; José A. L. da Silva; João J. R. Fraústo da Silva; Armando J. L. Pombeiro

2007-01-01

39

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

40

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

41

Transformation of chenodeoxycholic acid to ursodeoxycholic acid in patients with Crohn's disease  

SciTech Connect

In vivo 7 beta-epimerization of chenodeoxycholic acid to ursodeoxycholic acid and the role of 7-ketolithocholic acid as an intermediate in this biotransformation were studied in 11 patients with Crohn's disease and in 5 healthy volunteers. The incorporation of deuterium into biliary ursodeoxycholic acid and 7-ketolithocholic acid was determined by computed gas chromatography-mass fragmentography after ingestion of a dideuterated chenodeoxycholic acid, chenodeoxycholic-11,12-d2 acid. The incorporation of deuterium into ursodeoxycholic acid increased to a peak level at 48 h in the patients with Crohn's disease, but was delayed in healthy volunteers. In 8 patients and 2 healthy controls there were small amounts of 7-ketolithocholic acid in bile. The incorporation of deuterium into 7-ketolithocholic acid was confirmed in only 2 patients and the peak level was noted at 48 h. These observations suggest that 7-ketolithocholic acid is an intermediate of this biotransformation in patients with Crohn's disease.

Miwa, H.; Yamamoto, M.; Nishida, T.; Yao, T.

1986-03-01

42

Construction of protein distance matrix based on amino acid indices and Discrete Fourier Transform.  

PubMed

Protein distance matrix is widely used in various protein sequence analyses, and mainly obtained by using pairwise sequence alignment scores or protein sequence homology, which fail to take into consideration of individual physical characteristics of protein sequences and amino acids, or a combination of these features. In this paper, a new method is therefore proposed for constructing protein distance matrix based on natural amino acid indices in combination with Discrete Fourier Transform (DFT). PMID:24110625

Chrysostomou, Charalambos; Seker, Huseyin

2013-07-01

43

Benzoic acid transformation via conjugation with peptides and final fate of conjugates in higher plants  

Microsoft Academic Search

Transformation of [114C]- and [714C] benzoic acids in sterile seedlings of maize (Zea mays) and pea (Pisum sativum) was studied. The tested labeled compounds were supplied in plants through roots as water solutions. The larger part of the assimilated benzoic acid forms conjugates with low-molecular-weight plant peptides. As a result of hydrolytic cleavage of the conjugation products, initial labeled benzoic

D. Chrikishvili; T. Sadunishvili; G. Zaalishvili

2006-01-01

44

Enhanced transformation of diphenylarsinic acid in soil under sulfate-reducing conditions.  

PubMed

Diphenylarsinic acid (DPAA) is known to be the major contaminant in soils where diphenylchloroarsine and diphenylcyanoarsine were abandoned after World Wars I and II. In this study, experimental model studies were performed to elucidate key factors regulating the transformation of DPAA under anaerobic soil conditions. The elimination of DPAA in Gleysol soils (Qiqihar and Shindori soils) was more rapid than in Mollisol and Regosol soils (Heihe and Ikarashi soils, respectively) during a 5-week incubation. No clear relationship between decreasing rates of DPAA concentrations and soil Eh values was found. The Ikarashi soil showed the slowest decrease in DPAA concentrations among the four soils, but the transformation of DPAA was notably enhanced by addition of exogenous sulfate together with acetate, cellulose or rice straw. Addition of molybdate, a specific inhibitor of sulfate reduction, resulted in the stagnation of DPAA transformation, suggesting that indigenous sulfate reducers play a role in DPAA transformation under anaerobic conditions. Arsenate, phenylarsonic acid, phenylmethylarsinic acid, diphenylmethylarsine oxide and three unknown compounds were detected as metabolites of DPAA. This is the first study to reveal enhancement of DPAA transformation under sulfate-reducing conditions. PMID:23069334

Guan, Ling; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

2012-10-02

45

Transformation of Monoaromatic hydrocarbons to organic acids in anoxic groundwater environment  

USGS Publications Warehouse

The transformation of benzene and a series of alkylbenzenes was studied in anoxic groundwater of a shallow glacial-outwash aquifer near Bemidji, Minnesota, U.S.A. Monoaromatic hydrocarbons, the most water-soluble components of crude oil, were transported downgradient of an oil spill, forming a plume of contaminated groundwater. Organic acids that were not original components of the oil were identified in the anoxic groundwater. The highest concentrations of these oxidized organic compounds were found in the anoxic plume where a decrease in concentrations of structurally related alkylbenzenes was observed. These results suggest that biological transformation of benzene and alkylbenzenes to organic acid intermediates may be an important attenuation process in anoxic environments. The transformation of a complex mixture of hydrocarbons to a series of corresponding oxidation products in an anoxic subsurface environment provides new insight into in situ anaerobic degradation processes. ?? 1990 Springer-Verlag New York Inc.

Cozzarelli, I. M.; Eganhouse, R. P.; Baedecker, M. J.

1990-01-01

46

RETINOIDAL BENZOIC ACIDS (AROTENOIDS) AND OTHER RETINOIDS INHIBIT IN VITRO TRANSFORMATION OF EPITHELIAL CELLS  

EPA Science Inventory

Five retinoids were calcluated for their ability to inhibit N-methyl-N'nitro-N-nitrosoguanidine (MNNG)-induccd transformation of primary rat trachcal epithelial (RTE) cells in culture at concentrations that did not affect cell survival. wo retinoidal benzoic acids (arotcnoids), R...

47

Genistein and Daidzein Stimulate Hyaluronic Acid Production in Transformed Human Keratinocyte Culture and Hairless Mouse Skin  

Microsoft Academic Search

We examined the effects of the soy isoflavones genistein (Gen) and daidzein (Dai) on the production of hyaluronic acid (HA) in a transformed human keratinocyte culture and in hairless mouse skin following topical application for 2 weeks. Gen and Dai, but not the glycosides thereof, significantly enhanced the production of HA in vitro and in vivo. Histochemistry using an HA-binding

Kouji Miyazaki; Tomoko Hanamizu; Ryoko Iizuka; Katsuyoshi Chiba

2002-01-01

48

Oxidative transformation of a naturally occurring okadaic acid diol ester by the diatom Thalassiosira weissflogii  

Microsoft Academic Search

The diarrhetic shellfish poisoning (DSP) toxin okadaic acid (1) is found in extracts of the dinoflagellate Prorocentrum lima together with a suite of diol esters such as 2. When 2 was added to the culture medium of the centric diatom Thalassiosira weissflogii, it was transformed into a range of products within three days. Three of these products, 3, 4 and

Tingmo Hu; Ian Burton; Jonathan M. Curtis; Michael A. Quilliam; John A. Walter; Anthony J. Windust; Jeffrey L. C. Wright

1999-01-01

49

Electrochemical technique and copper-promoted transformations: selective hydroxylation and amination of arylboronic acids.  

PubMed

An efficient and selective electrosynthesis of phenols and anilines from arylboronic acids in aqueous ammonia is achieved in an undivided cell. By simply changing the concentration of aqueous ammonia and the anode potential, good yields of phenols and anilines can be obtained chemoselectively with high reaction rates. We propose that anodic oxidation could have played an important role in these transformations. PMID:23808633

Qi, Hong-Lin; Chen, Dong-Song; Ye, Jian-Shan; Huang, Jing-Mei

2013-07-11

50

Quick-charging a sealed lead-acid battery with unregulated transformer-rectifiers  

NASA Astrophysics Data System (ADS)

An overview is given of sealed lead-acid battery advantages. Unregulated transformer-rectifier unit flat charging advantages are discussed, and a proposed modified charging method is presented. A test plan to verify the system along with expected results is presented.

Kuest, Jeffrey S.; Borges de Oliveira, A.

51

Agrobacterium tumefaciens -mediated transformation of the antitumor clavaric acid-producing basidiomycete Hypholoma sublateritium  

Microsoft Academic Search

The basidiomycete Hypholoma sublateritium produces clavaric acid, an antitumor isoprenoid compound. Arthrospores of this fungus were transformed by Agrobacterium tumefaciens-mediated conjugation. Five plasmids carrying different regulatory sequences to drive expression of the hph (hygromycin phosphotransferase) gene were tested. The promoter used was critically important in order to express heterologous genes in H. sublateritium. Constructions carrying the Agaricus bisporus glyceraldehyde-3-phosphate dehydrogenase

R. P. Godio; R. Fouces; E. J. Gudiña; J. F. Martín

2004-01-01

52

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

53

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

54

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

55

Prevention of cultured rat stellate cell transformation and endothelin-B receptor upregulation by retinoic acid.  

PubMed

1 Physiologically, perisinusoidal hepatic stellate cells (HSC) are quiescent and store retinoids. During liver injury and in cell culture, HSC transform into proliferating myofibroblast-like cells that express alpha-smooth muscle actin (alpha-sma) and produce excessive amounts of extracellular matrix. During transformation (also known as activation), HSC are depleted of the retinoid stores, and their expression of the endothelin-1 (ET-1) system is increased. ET-1 causes contraction of transformed HSC and is implicated in their proliferation and fibrogenic activity. In order to understand the association between retinoids, ET-1 and the activation of HSC, we investigated the effect of 13-cis-retinoic acid on the transformation of cultured HSC and the expression of ET-1 system. 2 HSC derived from normal rat liver were maintained for 10-12 days in a medium supplemented with 5% serum and containing 2.5 micro M retinoic acid without or with 50 nM ET-1 (ETA+ETB agonist) or sarafotoxin S6c (ETB agonist). In another set of experiments, cells treated for 10-12 days with vehicle (ethanol) or retinoic acid were challenged with ET-1 or sarafotoxin S6c, and various determinations were made at 24 h. 3 Retinoic acid inhibited transformation and proliferation of HSC as assessed by morphological characteristics, expression of alpha-sma, bromodeoxyuridine incorporation and cell count. Retinoic acid also prevented upregulation of ETB receptors without affecting ET-1 or ETA expression. Total protein synthesis ([(3)H]leucine incorporation), collagen alpha types I mRNA expression and collagen synthesis ([(3)H]proline incorporation) were lower in retinoic acid-treated cells. Although ET-1-treated cells were morphologically similar to the control cells, their expression of alpha-smooth muscle actin was significantly inhibited. The presence of retinoic acid in the medium during treatment with ET-1 caused further reduction in the expression of alpha-smooth muscle actin. ET-1 and sarafotoxin S6c stimulated total protein synthesis in vehicle- and retinoic acid-treated cells, but collagen synthesis only in the latter. 4 These results showing prevention of HSC activation and negative regulation of ETB receptor expression in them by retinoic acid may have important pathophysiologic implications. PMID:12813000

Chi, Xuedong; Anselmi, Kristin; Watkins, Simon; Gandhi, Chandrashekhar R

2003-06-01

56

Chemical characteristics of fulvic acids from Arctic surface waters: Microbial contributions and photochemical transformations  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) originating from the extensive Arctic tundra is an important source of organic material to the Arctic Ocean. Chemical characteristics of whole water dissolved organic matter (DOM) and the fulvic acid fraction of DOM were studied from nine surface waters in the Arctic region of Alaska to gain insight into the extent of microbial and photochemical transformation of this DOM. All the fulvic acids had a strong terrestrial/higher plant signature, with uniformly depleted ?13C values of -28‰, and low fluorescence indices around 1.3. Several of the measured chemical characteristics of the Arctic fulvic acids were related to water residence time, a measure of environmental exposure to sunlight and microbial activity. For example, fulvic acids from Arctic streams had higher aromatic contents, higher specific absorbance values, lower nitrogen content, lower amino acid-like fluorescence and were more depleted in ?15N relative to fulvic acids isolated from lake and coastal surface waters. The differences in the nitrogen signature between the lake and coastal fulvic acids compared to the stream fulvic acids indicated that microbial contributions to the fulvic acid pool increased with increasing water residence time. The photo-lability of the fulvic acids was positively correlated with water residence time, suggesting that the fulvic acids isolated from source waters with larger water residence times (i.e., lakes and coastal waters) have experienced greater photochemical degradation than the stream fulvic acids. In addition, many of the initial differences in fulvic acid chemical characteristics across the gradient of water residence times were consistent with changes observed in fulvic acid photolysis experiments. Taken together, results from this study suggest that photochemical processes predominantly control the chemical character of fulvic acids in Arctic surface waters. Our findings show that hydrologic transport in addition to biogeochemical alteration of the organic matter must be considered in order to predict the ultimate fate of Arctic DOM.

Cory, Rose M.; McKnight, Diane M.; Chin, Yu-Ping; Miller, Penney; Jaros, Chris L.

2007-12-01

57

Characteristics of Palm Fatty Acid Ester (PFAE), a New Vegetable Based Insulating Oil for Transformers  

NASA Astrophysics Data System (ADS)

We have developed new vegetable based insulating oil for transformers called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. The oxidative stability, biodegradability and acute toxicity to fish of PFAE has also been determined to be superior to mineral oil. In this paper, in order to optimize the characteristics of fatty acid esters originating from palm oil, several kinds of fatty acid alkyl esters were first synthesized in the laboratory by the molecular design technique and the transesterification from fatty acid methyl esters and alkyl alcohols. Next the electro-chemical characteristics of the fatty acid alkyl esters as insulating oil were analyzed.

Suzuki, Takashi; Kanoh, Takaaki; Koide, Hidenobu; Hikosaka, Tomoyuki

58

Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells  

PubMed Central

Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy.

Gottlicher, Martin; Minucci, Saverio; Zhu, Ping; Kramer, Oliver H.; Schimpf, Annemarie; Giavara, Sabrina; Sleeman, Jonathan P.; Lo Coco, Francesco; Nervi, Clara; Pelicci, Pier Giuseppe; Heinzel, Thorsten

2001-01-01

59

Production of cis,cis -muconic acid from benzoic acid via microbial transformation  

Microsoft Academic Search

For the production ofcis,cis-muconic acidvia biocatalytic conversion reactions from a toxic cosubstrate, benzoic acid, a fed-batch process using computer-controlled DO-stat\\u000a feeding was developed. The mutant strain ofPseudomonas putida BM014 producedcis,cis-muconic acid from benzoic acid with high conversion yield. More than 32 g\\/L ofcis,cis-muconic acid was accumulated in 42h and a productivity of 1.4 g\\/(L·h) was achieved.

Sang Gu Bang; Won Jae Choi; Cha Yong Choi; Moo Hwan Cho

1996-01-01

60

Inhibition of Myc-induced cell transformation by brain acid-soluble protein 1 (BASP1)  

PubMed Central

Cell transformation by the Myc oncoprotein involves transcriptional activation or suppression of specific target genes with intrinsic oncogenic or tumor-suppressive potential, respectively. We have identified the BASP1 (CAP-23, NAP-22) gene as a novel target suppressed by Myc. The acidic 25-kDa BASP1 protein was originally isolated as a cortical cytoskeleton-associated protein from rat and chicken brain, but has also been found in other tissues and subcellular locations. BASP1 mRNA and protein expression is specifically suppressed in fibroblasts transformed by the v-myc oncogene, but not in cells transformed by other oncogenic agents. The BASP1 gene encompasses 2 exons separated by a 58-kbp intron and a Myc-responsive regulatory region at the 5? boundary of untranslated exon 1. Bicistronic expression of BASP1 and v-myc from a retroviral vector blocks v-myc-induced cell transformation. Furthermore, ectopic expression of BASP1 renders fibroblasts resistant to subsequent cell transformation by v-myc, and exogenous delivery of the BASP1 gene into v-myc-transformed cells leads to significant attenuation of the transformed phenotype. The inhibition of v-myc-induced cell transformation by BASP1 also prevents the transcriptional activation or repression of known Myc target genes. Mutational analysis showed that the basic N-terminal domain containing a myristoylation site, a calmodulin binding domain, and a putative nuclear localization signal is essential for the inhibitory function of BASP1. Our results suggest that down-regulation of the BASP1 gene is a necessary event in myc-induced oncogenesis and define the BASP1 protein as a potential tumor suppressor.

Hartl, Markus; Nist, Andrea; Khan, M. Imran; Valovka, Taras; Bister, Klaus

2009-01-01

61

Conjugated Linoleic Acid Accumulation via 10Hydroxy12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus  

Microsoft Academic Search

Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or

JUN OGAWA; KENJI MATSUMURA; SHIGENOBU KISHINO; YORIKO OMURA; SAKAYU SHIMIZU

2001-01-01

62

Microbiological transformation of the triterpene nigranoic acid by the freshwater fungus Dictyosporium heptasporum.  

PubMed

The microbiological transformation of the triterpene nigranoic acid (3,4-secocycloarta-4(28),24(Z)-diene-3,26-dioic acid) (1) to 3,4-secocycloarta-4(28),17(20),24(Z)-triene-7?-hydroxy-16?,26-lactone-3-oic acid (2) and 3,4-secocycloarta-4(28),17(20)(Z),24(Z)-triene-7?-hydroxy-16?-methoxy-3,26-dioic acid (3) by the freshwater fungus Dictyosporium heptasporum YMF1.01213 has been demonstrated. The structures of the biotransformation products were determined by spectroscopic and MS analyses. Compound 2, characterized by the presence of a formed C-16/C-26 ester bridge, provided a novel nine-membered lactone ring structural skeleton for 3,4-secocycloartane triterpenoid derivatives. In addition, Compounds 1-3 exhibited weak anti-HIV activity in vitro. Compounds 2 and 3 were reported for the first time as natural product derivatives. PMID:23600754

Sun, Rong; Song, Hong-Chuan; Yang, Yu-Hong; Yang, Pan; Yang, Dong-Yan; Shen, Kai-Ze; Xu, Yao-Bo; Gao, Yan-Xiu; Chen, Ye-Gao; Dong, Jin-Yan

2013-04-22

63

Inhibition of monomethylarsonous acid (MMA(III))-induced cell malignant transformation through restoring dysregulated histone acetylation.  

PubMed

Inorganic arsenic (iAs) and its high toxic metabolite, monomethylarsonous acid (MMA(III)), are able to induce malignant transformation of human cells. Chronic exposure to these chemicals is associated with an increased risk of developing multiple cancers in human. However, the mechanisms contributing to iAs/MMA(III)-induced cell malignant transformation and carcinogenesis are not fully elucidated. We recently showed that iAs/MMA(III) exposure to human cells led to a decreased level of histone acetylation globally, which was associated with an increased sensitivity to arsenic cytotoxicity. In the current study, it demonstrated that prolonged exposure to low-level MMA(III) in human urothelial cells significantly increased the expression and activity of histone deacetylases (HDACs) with an associated reduction of histone acetylation levels both globally and lysine specifically. Administration of the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), at 4 weeks after the initial MMA(III) treatment inhibited the MMA(III)-mediated up-regulation of the expression and activities of HDACs, leading to increase histone acetylation and prevention of MMA(III)-induced malignant transformation. These new findings suggest that histone acetylation dysregulation may be a key mechanism in MMA(III)-induced malignant transformation and carcinogenesis, and that HDAC inhibitors could be targeted to prevent or treat iAs-related cancers. PMID:23891734

Ge, Yichen; Gong, Zhihong; Olson, James R; Xu, Peilin; Buck, Michael J; Ren, Xuefeng

2013-07-26

64

Transposon-5 mutagenesis transforms Corynebacterium matruchotii to synthesize novel hybrid fatty acids that functionally replace corynomycolic acid.  

PubMed

Enzymes within the biosynthetic pathway of mycolic acid (C(60)-C(90) a-alkyl,b-hydroxyl fatty acid) in Mycobacterium tuberculosis are attractive targets for developing new anti-tuberculosis drugs. We have turned to the simple model system of Corynebacterium matruchotii to study the terminal steps in the anabolic pathway of a C32 mycolic acid called corynomycolic acid. By transposon-5 mutagenesis, we transformed C. matruchotii into a mutant that is unable to synthesize corynomycolic acid. Instead, it synthesized two related series of novel fatty acids that were released by saponification from the cell wall fraction and from two chloroform/methanol-extractable glycolipids presumed to be analogues of trehalose mono- and di-corynomycolate. By chemical analyses and MS, we determined the general structure of the two series to be 2,4,6,8,10-penta-alkyl decanoic acid for the larger series (C(70)-C(77)) and 2,4,6,8-tetra-alkyl octanoic acid for the smaller series (C(52)-C(64)), both containing multiple keto groups, hydroxy groups and double bonds. The mutant was temperature-sensitive, aggregated extensively, grew very slowly relative to the wild type, and was resistant to the presence of lysozyme. We suggest that a regulatory protein that normally prevents the transfer of the condensation product back to b-ketoacyl synthase in the corynomycolate synthase system of the wild type was inactivated in the mutant. This will result in multiple Claisen-type condensation and the formation of two similar series of these complex hybrid fatty acids. A similar protein in M. tuberculosis would be an attractive target for new drug discovery. PMID:12879902

Takayama, Kuni; Hayes, Barry; Vestling, Matha M; Massey, Randall J

2003-07-15

65

Transposon-5 mutagenesis transforms Corynebacterium matruchotii to synthesize novel hybrid fatty acids that functionally replace corynomycolic acid.  

PubMed Central

Enzymes within the biosynthetic pathway of mycolic acid (C(60)-C(90) a-alkyl,b-hydroxyl fatty acid) in Mycobacterium tuberculosis are attractive targets for developing new anti-tuberculosis drugs. We have turned to the simple model system of Corynebacterium matruchotii to study the terminal steps in the anabolic pathway of a C32 mycolic acid called corynomycolic acid. By transposon-5 mutagenesis, we transformed C. matruchotii into a mutant that is unable to synthesize corynomycolic acid. Instead, it synthesized two related series of novel fatty acids that were released by saponification from the cell wall fraction and from two chloroform/methanol-extractable glycolipids presumed to be analogues of trehalose mono- and di-corynomycolate. By chemical analyses and MS, we determined the general structure of the two series to be 2,4,6,8,10-penta-alkyl decanoic acid for the larger series (C(70)-C(77)) and 2,4,6,8-tetra-alkyl octanoic acid for the smaller series (C(52)-C(64)), both containing multiple keto groups, hydroxy groups and double bonds. The mutant was temperature-sensitive, aggregated extensively, grew very slowly relative to the wild type, and was resistant to the presence of lysozyme. We suggest that a regulatory protein that normally prevents the transfer of the condensation product back to b-ketoacyl synthase in the corynomycolate synthase system of the wild type was inactivated in the mutant. This will result in multiple Claisen-type condensation and the formation of two similar series of these complex hybrid fatty acids. A similar protein in M. tuberculosis would be an attractive target for new drug discovery.

Takayama, Kuni; Hayes, Barry; Vestling, Matha M; Massey, Randall J

2003-01-01

66

New High-Resolution Analysis of the ? 7 and ? 9 Fundamental Bands of trans-Formic Acid by Fourier Transform Infrared and Millimeter-Wave Spectroscopy  

Microsoft Academic Search

The high-resolution (0.002 cm?1) spectrum of the ?7 (OCO scissor mode) and ?9 (COH torsion mode) fundamental bands of trans-formic acid (HCOOH) at 15.8 ?m was recorded by Fourier transform infrared spectroscopy. In addition, millimeter-wave transitions within the 71 and 91 vibrational states were measured in the spectral range 340–600 GHz. Using these new experimental data, an extensive analysis of

A. Perrin; J.-M Flaud; B. Bakri; J. Demaison; O. Baskakov; S. V. Sirota; M. Herman; J. Vander Auwera

2002-01-01

67

Anti-transforming nature of ascorbic acid and its derivatives examined by two-stage cell transformation using BALB\\/c 3T3 cells  

Microsoft Academic Search

The anti-transforming effects of sodium ascorbate and its stable derivatives were examined in the two-stage transformation assay. When BALB\\/c 3T3 cells were treated with 0.2 ?g\\/ml 20-methylcholanthrene as an initiator, and 100 ng\\/ml 12-O-tetradecanoylphorbol-13-acetate as a promoter, the addition at the promotion stage of l-ascorbic acid-2-phosphate ester magnesium (APM) was most marked in the inhibition of transformation. The inhibitory effects

Toshiyuki Tsuchiya; Eiko Kato-Masatsuji; Toshi Tsuzuki; Makoto Umeda

2000-01-01

68

Anaerobic Transformation of Alkanes to Fatty Acids by a Sulfate-Reducing Bacterium, Strain Hxd3  

PubMed Central

Strain Hxd3, an alkane-degrading sulfate reducer previously isolated and described by Aeckersberg et al. (F. Aeckersberg, F. Bak, and F. Widdel, Arch. Microbiol. 156:5-14, 1991), was studied for its alkane degradation mechanism by using deuterium and 13C-labeled compounds. Deuterated fatty acids with even numbers of C atoms (C-even) and 13C-labeled fatty acids with odd numbers of C atoms (C-odd) were recovered from cultures of Hxd3 grown on perdeuterated pentadecane and [1,2-13C2]hexadecane, respectively, underscoring evidence that C-odd alkanes are transformed to C-even fatty acids and vice versa. When Hxd3 was grown on unlabeled hexadecane in the presence of [13C]bicarbonate, the resulting 15:0 fatty acid, which was one carbon shorter than the alkane, incorporated a 13C label to form its carboxyl group. The same results were observed when tetradecane, pentadecane, and perdeuterated pentadecane were used as the substrates. These observations indicate that the initial attack of alkanes includes both carboxylation with inorganic bicarbonate and the removal of two carbon atoms from the alkane chain terminus, resulting in a fatty acid one carbon shorter than the original alkane. The removal of two terminal carbon atoms is further evidenced by the observation that the [1,2-13C2]hexadecane-derived fatty acids contained either two 13C labels located exclusively at their acyl chain termini or none at all. Furthermore, when perdeuterated pentadecane was used as the substrate, the 14:0 and 16:0 fatty acids formed both carried the same numbers of deuterium labels, while the latter was not deuterated at its carboxyl end. These observations provide further evidence that the 14:0 fatty acid was initially formed from perdeuterated pentadecane, while the 16:0 fatty acid was produced after chain elongation of the former fatty acid with nondeuterated carbon atoms. We propose that strain Hxd3 anaerobically transforms an alkane to a fatty acid through a mechanism which includes subterminal carboxylation at the C-3 position of the alkane and elimination of the two adjacent terminal carbon atoms.

So, Chi Ming; Phelps, Craig D.; Young, L. Y.

2003-01-01

69

New Methodology for Computation of the Earth's Polarizability from Telluric Borehole Logging Measurements Taken at Different Frequencies  

NASA Astrophysics Data System (ADS)

An important approach for computation of the earth's polarizability is achieved by developing a novel method with new parameters called Natural Percent Frequency Effect (NPFE) and Natural Metal Factor (NMF) resulting from telluric logging data taken at different frequencies. The essential advantage of the developed approach relies on using natural electrical currents instead of an artificial electrical source usually needed in the standard frequency domain applied in the induced polarization method. Furthermore, a good qualitative correlation has been found between the new parameters and those of the traditional induced polarization method obtained in time and frequency domains. The new method has been tested in well 32 in the Rouez mine in France, where sulphide mineralization is well known to occur.

Asfahani, Jamal

70

Identification of transforming activity of free fatty acid receptor 2 by retroviral expression screening.  

PubMed

Gallbladder cancer (GBC) is a highly fatal malignancy in humans. Genetic alterations in KRAS or TP53 as well as overexpression of ERBB2 have been shown to contribute to the development of certain types of GBC. However, many cases of GBC do not harbor such genetic changes, with other transforming events awaiting discovery. We here tried to identify novel cancer-promoting genes in GBC, with the use of a retroviral cDNA expression library. A retroviral cDNA expression library was constructed from a surgically resected clinical specimen of GBC, and was used to infect 3T3 fibroblasts in a focus formation assay. cDNA incorporated into the transformed foci was rescued by PCR. One such cDNA was found to encode free fatty acid receptor 2 (FFAR2), a G protein-coupled receptor for short-chain fatty acids. The oncogenic potential of FFAR2 was confirmed both in vitro with the focus formation assay and by evaluation of cell growth in soft agar as well as in vivo with a tumorigenicity assay in nude mice. The isolated FFAR2 cDNA had no sequence alterations, suggesting that upregulation of FFAR2 expression may contribute to malignant transformation. Indeed, all of quantitative RT-PCR, in situ hybridization, and immunohistochemical analyses showed that the amount of FFAR2 mRNA and its protein product was increased in digestive tract cancer specimens. Furthermore, short-chain fatty acids potentiated the mitogenic action of FFAR2 in 3T3 cells. Our data thus, for the first time, implicate FFAR2 in carcinogenesis of the digestive tract. PMID:19780758

Hatanaka, Hisashi; Tsukui, Mamiko; Takada, Shuji; Kurashina, Kentaro; Choi, Young Lim; Soda, Manabu; Yamashita, Yoshihiro; Haruta, Hidenori; Hamada, Toru; Ueno, Toshihide; Tamada, Kiichi; Hosoya, Yoshinori; Sata, Naohiro; Yasuda, Yoshikazu; Nagai, Hideo; Sugano, Kentaro; Mano, Hiroyuki

2009-09-04

71

Ursolic acid, an antagonist for transforming growth factor (TGF)-beta1.  

PubMed

Transforming growth factor-beta (TGF-beta), a multifunctional cytokine which is involved in extracellular matrix modulation, has a major role in the pathogenesis and progression of fibrotic diseases. We now report the effects of ursolic acid on TGF-beta1 receptor binding and TGF-beta1-induced cellular functions in vitro. Ursolic acid inhibited [(125)I]-TGF-beta1 receptor binding to Balb/c 3T3 mouse fibroblasts with an IC(50) value of 6.9+/-0.8 microM. Ursolic acid dose-dependently recovered reduced proliferation of Minc Mv1Lu cells in the presence of 5 nM of TGF-beta1 and attenuated TGF-beta1-induced collagen synthesis and production in human fibroblasts. Molecular dynamics simulations suggest that ursolic acid may interact with the hydrophobic region of the dimeric interface and thereby inhibit the binding of TGF-beta1 to its receptor. All these findings taken together show that ursolic acid functions as an antagonist for TGF-beta1. This is the first report to show that a small molecule can inhibit TGF-beta1 receptor binding and influence functions of TGF-beta1. PMID:15147868

Murakami, Shigeru; Takashima, Hajime; Sato-Watanabe, Mariko; Chonan, Sumi; Yamamoto, Koji; Saitoh, Masako; Saito, Shiuji; Yoshimura, Hiromitsu; Sugawara, Koko; Yang, Junshan; Gao, Nannan; Zhang, Xinggao

2004-05-21

72

Enhancement of the reductive transformation of pentachlorophenol by polycarboxylic acids at the iron oxide–water interface  

Microsoft Academic Search

The enhancement effect of polycarboxylic acids on reductive dechlorination transformation of pentachlorophenol (PCP) reacting with iron oxides was studied in anoxic suspension. Batch experiments were performed with three species of iron oxides (goethite, lepidocrocite and hematite) and four species of polycarboxylic acids (oxalate, citrate, succinate, and tartrate) through anoxic abiotic reactors. The chemical analyses and morphological observation from scanning and

Fangbai Li; Xugang Wang; Yongtao Li; Chengshuai Liu; Fang Zeng; Lijia Zhang; Mingde Hao; Huada Ruan

2008-01-01

73

Drinking water disinfection byproduct iodoacetic acid induces tumorigenic transformation of NIH3T3 cells.  

PubMed

Iodoacetic acid (IAA) and iodoform (IF) are unregulated iodinated disinfection byproducts (DBPs) found in drinking water. Their presence in the drinking water of China has not been documented. Recently, the carcinogenic potential of IAA and IF has been a concern because of their mutagenicity in bacteria and genotoxicity in mammalian cells. Therefore, we measured their concentrations in Shanghai drinking water and assessed their cytotoxicity, genotoxicity, and ability to transform NIH3T3 cells to tumorigenic lines. The concentrations of IAA and IF in Shanghai drinking water varied between summer and winter with maximum winter levels of 2.18 ?g/L IAA and 0.86 ?g/L IF. IAA with a lethal concentration 50 (LC50) of 2.77 ?M exhibited more potent cytotoxicity in NIH3T3 cells than IF (LC50 = 83.37 ?M). IAA, but not IF, induced a concentration-dependent DNA damage measured by ?-H2AX staining and increased tail moment in single-cell gel electrophoresis. Neither IAA nor IF increased micronucleus frequency. Prolonged exposure of NIH3T3 cells to IAA increased the frequencies of transformed cells with anchorage-independent growth and agglutination with concanavalin A. IAA-transformed cells formed aggressive fibrosarcomas after inoculation into Balb/c nude mice. This study demonstrated that IAA has a biological activity that is consistent with a carcinogen and human exposure should be of concern. PMID:23641915

Wei, Xiao; Wang, Shu; Zheng, Weiwei; Wang, Xia; Liu, Xiaolin; Jiang, Songhui; Pi, Jingbo; Zheng, Yuxin; He, Gengsheng; Qu, Weidong

2013-05-21

74

Telomerase inhibition by peptide nucleic acids reverses 'immortality' of transformed human cells.  

PubMed

Telomerase activity, the ability to add telomeric repeats to the ends of chromosomes, has been detected in most immortal cell lines including tumor cells, but is low or absent in most diploid, mortal cells such as those of somatic tissues. Peptide nucleic acids (PNAs), analogs of DNA or RNA which bind to complementary nucleic acids with very high affinity, were co-electroporated into immortal human cells along with a selectable plasmid. Introduction of PNAs inverse-complementary to telomerase RNA effectively inhibited telomerase activity in intact cells, shortened telomeres, reduced colony size, and arrested cell proliferation after a lag period of 5-30 cell generations, consistent with suppression of their 'immortality'. Electroporation of selection plasmid alone had no effect, while PNAs of altered sequence were markedly less effective in each assay. This constitutes the first demonstration of cell growth arrest through telomerase inhibition, upon treatment of intact cells with an exogenous compound which can be efficiently delivered in vivo. The phenotype of telomerase-inhibited transformed cells differs from senescence of normal diploid fibroblasts, but rather resembles the crisis state of incompletely transformed cells. PMID:10597217

Shammas, M A; Simmons, C G; Corey, D R; Shmookler Reis, R J

1999-11-01

75

Transformation of hematopoietic cells by the Ski oncoprotein involves repression of retinoic acid receptor signaling.  

PubMed

The Ski oncogene has dramatic effects on the differentiation of several different cell types. It induces the differentiation of quail embryo cells into myoblasts and arrests the differentiation of chicken hematopoietic cells. The mechanism that Ski uses to carry out these disparate biological activities is unknown. However, we were struck by the similarity of these effects to those of certain members of the nuclear hormone receptor family. Both Ski and the thyroid hormone receptor-derived oncogene v-ErbA can arrest the differentiation of avian erythroblasts, and v-Ski-transformed avian multipotent progenitor cells resemble murine hematopoietic cells that express a dominant-negative form of the retinoic acid receptor, RARalpha. In this paper, we have tested the hypothesis that v-Ski and its cellular homologue c-Ski exert their effects by interfering with nuclear hormone receptor-induced transcription. We demonstrate that Ski associates with the RAR complex and can repress transcription from a retinoic acid response element. The physiological significance of this finding is demonstrated by the ability of high concentrations of a RARalpha-specific ligand to abolish v-Ski-induced transformation of the multipotent progenitors. These results strongly suggest that the ability of Ski to alter cell differentiation is caused in part by the modulation of RAR signaling pathways. PMID:9736711

Dahl, R; Kieslinger, M; Beug, H; Hayman, M J

1998-09-15

76

Role of Oxalic Acid Overexcretion in Transformations of Toxic Metal Minerals by Beauveria caledonica  

PubMed Central

The fungus Beauveria caledonica was highly tolerant to toxic metals and solubilized cadmium, copper, lead, and zinc minerals, converting them into oxalates. This fungus was found to overexcrete organic acids with strong metal-chelating properties (oxalic and citric acids), suggesting that a ligand-promoted mechanism was the main mechanism of mineral dissolution. Our data also suggested that oxalic acid was the main mineral-transforming agent. Cadmium, copper, and zinc oxalates were precipitated by the fungus in the local environment and also in association with the mycelium. The presence of toxic metal minerals often led to the formation of mycelial cords, and in the presence of copper-containing minerals, these cords exhibited enhanced excretion of oxalic acid, which resulted in considerable encrustation of the cords by copper oxalate hydrate (moolooite). It was found that B. caledonica hyphae and cords were covered by a thick hydrated mucilaginous sheath which provided a microenvironment for chemical reactions, crystal deposition, and growth. Cryo-scanning electron microscopy revealed that mycogenic metal oxalates overgrew parental fungal hyphae, leaving a labyrinth of fungal tunnels within the newly formed mineral matter. X-ray absorption spectroscopy revealed that oxygen ligands played a major role in metal coordination within the fungal biomass during the accumulation of mobilized toxic metals by B. caledonica mycelium; these ligands were carboxylic groups in copper phosphate-containing medium and phosphate groups in pyromorphite-containing medium.

Fomina, M.; Hillier, S.; Charnock, J. M.; Melville, K.; Alexander, I. J.; Gadd, G. M.

2005-01-01

77

Metabolism of fatty acids and lipid hydroperoxides in human body monitoring with Fourier transform Infrared Spectroscopy  

PubMed Central

Background The metabolism of dietary fatty acids in human has been measured so far using human blood cells and stable-isotope labeled fatty acids, however, no direct data was available for human peripheral tissues and other major organs. To realize the role of dietary fatty acids in human health and diseases, it would be eager to develop convenient and suitable method to monitor fatty acid metabolism in human. Results We have developed the measurement system in situ for human lip surface lipids using the Fourier transform infrared spectroscopy (FTIR) – attenuated total reflection (ATR) detection system with special adaptor to monitor metabolic changes of lipids in human body. As human lip surface lipids may not be much affected by skin sebum constituents and may be affected directly by the lipid constituents of diet, we could detect changes of FTIR-ATR spectra, especially at 3005~3015 cm-1, of lip surface polyunsaturated fatty acids in a duration time-dependent manner after intake of the docosahexaenoic acid (DHA)-containing triglyceride diet. The ingested DHA appeared on the lip surface and was detected by FTIR-ATR directly and non-invasively. It was found that the metabolic rates of DHA for male volunteer subjects with age 60s were much lower than those with age 20s. Lipid hydroperoxides were found in lip lipids which were extracted from the lip surface using a mixture of ethanol/ethylpropionate/iso-octane solvents, and were the highest in the content just before noon. The changes of lipid hydroperoxides were detected also in situ with FTIR-ATR at 968 cm-1. Conclusion The measurements of lip surface lipids with FTIR-ATR technique may advance the investigation of human lipid metabolism in situ non-invasively.

Yoshida, Satoshi; Zhang, Qin-Zeng; Sakuyama, Shu; Matsushima, Satoshi

2009-01-01

78

Fourier transform infrared spectroscopic studies of hydrogen bonding interactions in materials containing carboxylic acid groups  

NASA Astrophysics Data System (ADS)

The results of Fourier transform infrared (FTIR) spectroscopic studies of the hydrogen bonding interactions in materials and blends containing carboxylic acid groups are presented. The self-association of p-n-alkoxybenzoic acids (AOBAs) exhibits liquid crystalline characteristics. The length of the terminal alkyl chain determines the crystal structure observed. For longer chain lengths (n = 7--18), an isotypic form is observed, where the segregation of the alkyl chains and aromatic rings allows for the stacking of the self-associated acid groups. This leads to infrared band splitting and a broadened carbonyl stretching region. The breadth can also be caused by the polymorphic state of the material, as in the case of the molecules possessing the shorter alkyl chains (n < 7). By blending these materials with amorphous polyethers, a competition for hydrogen bonds is induced. By diluting the AOBAs with the polyethers, the highly ordered state is disrupted and access to inter-associating partners is increased. Copolymers of methacrylic acid with styrene and 2,3-dimethylbutadiene were synthesized. Temperature stability (decreased anhydride formation) of these materials was improved by decreasing the number of adjacent methacrylic acid groups (<10 mol%). The self-association equilibrium constants were also calculated for each copolymer and compared with that of a low molecular weight analogue. The value of the self-association equilibrium constant increased with increasing chain flexibility. Therefore, an infinitely flexible chain should possess the same value of the self-association equilibrium constant as the low molecular weight analogue. The styrene copolymer was then blended with poly(tetrahydrofuran) and an inter-association equilibrium constant was determined. Despite an order of magnitude difference between the self- and inter-association equilibrium constants, the blends are miscible.

Cleveland, Christopher Scott

79

Conformational transformation in squaric acid induced by near-IR laser light.  

PubMed

Two conformers of monomeric squaric acid (3,4-dihydroxy-3-cyclobutene-1,2-dione) were studied using the matrix-isolation method. Both forms of the compound, differing in rotation of one of the OH groups by 180°, were trapped from the gas phase into a low-temperature nitrogen matrix, whereas only the lowest-energy conformer was trapped in solid argon and in solid neon. Narrowband near-infrared laser light was used to induce transformation of the most stable form of squaric acid (having C2v symmetry) into the higher-energy conformer (Cs symmetry). Effective stabilization of the photogenerated species occurred only for the compound isolated in a nitrogen matrix. Moreover, the stabilization of the higher-energy Cs conformer of squaric acid by the solid nitrogen environment was found to strongly depend on the trapping site in the matrix. The spectroscopic characterization of the higher energy Cs conformer is reported here for the first time. PMID:23742190

Lapinski, Leszek; Reva, Igor; Rostkowska, Hanna; Halasa, Anna; Fausto, Rui; Nowak, Maciej J

2013-06-13

80

Apoptosis and Altered Redox State Induced by Caffeic Acid Phenethyl Ester (CAPE) in Transformed Rat Fibroblast Cells1  

Microsoft Academic Search

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of bee hives, was shown previously to block tumor promoter- and carcin ogen-generated oxidative processes in several assays and to engender differential toxicity to some transformed cells. To study the mechanisms of CAPE-induced differential cytotoxicity, nontumorigenic rat embryo fibro- blasts (CREF) and adenovirus (type 5)-transformed CREF cells (Wt3A) were

Chia Chiao; Adelaide M. Carothers; Dezider Grunberger; Gregory Solomon; Gloria A. Preston; J. Carl Barrett

81

FT-IR spectroscopic study of phase transformation of chloropinnoite in boric acid solution at 303 K  

Microsoft Academic Search

The dissolution and transformation of chloropinnoite in boric acid solution at 303 K has been studied using FT-IR difference spectroscopic technique. After equilibrium was reached, liquid and solid phases were separated and FT-IR spectra of each phase were recorded, FT-IR spectroscopic analysis of solid phases indicated that the transformation products, with the increase of boron-concentration in solution, were 2MgO?·?3B2O3?·?15H2O (inderite),

Liu Zhihong; Gao Shiyang; Xia Shuping

2003-01-01

82

Gypsum–anhydrite transformation in hot acidic manganese sulfate solution. A comparative kinetic study employing several analytical methods  

Microsoft Academic Search

Transformation of calcium sulfate dihydrate (gypsum) into anhydrous calcium sulfate (anhydrite) proceeds slowly in a manganese sulfate\\/sulfuric acid medium (36 g Mn2+\\/kg of solution and 36 g H2SO4\\/kg of solution) at 95 °C, conditions pertinent to some industrial processes, without any apparent intermediate species. The kinetics of the transformation have been probed by following the change in mole fraction of

Helen E. Farrah; Geoffrey A. Lawrance; Erica J. Wanless

2004-01-01

83

Ultraviolet-Induced Decrease in Integration of Haemophilus influenzae Transforming Deoxyribonucleic Acid in Sensitive and Resistant Cells  

PubMed Central

The decrease in integration of transforming deoxyribonucleic acid (DNA) caused by ultraviolet irradiation of the DNA was found to be independent of the presence or absence of excision repair in the recipient cell. Much of the ultraviolet-induced inhibition of integration resulted from the presence in the transforming DNA of pyrimidine dimers, as judged by the photoreactivability of the inhibition with yeast photoreactivating enzyme. The inhibition of integration made only a small contribution to the inactivation of transforming ability of the DNA by ultraviolet radiation.

Muhammed, Amir; Setlow, Jane K.

1970-01-01

84

CO2 fixation and transformation by a dinuclear copper cryptate under acidic conditions.  

PubMed

CO2 fixation and transformation by metal complexes continuously receive attention from the viewpoint of carbon resources and environmental concerns. We found that the dinuclear copper(II) cryptate [Cu2L1](ClO4)4 (1; L1 = N[(CH2)2NHCH2(m-C6H4)CH2NH-(CH2)2]3N) can easily take up atmospheric CO2 even under weakly acidic conditions at room temperature and convert it from bicarbonate into carbonate monoesters in alcohol solution. The compounds [Cu2L1(mu-O2COH)](ClO4)3 (2), [Cu2L1(mu-O2COR)](ClO4)3 (3: R = CH3; 4: R = C2H5; 5: R = C3H7; 6: R = C4H9; 7: R = C5H11; 8: R = CH2CH2OH), [Cu2L1(mu-O2CCH3)](ClO4)3 (9), and [Cu2L1(OH2)(NO3)](NO3)3 (10) were characterized by IR spectroscopy and ESI-MS. The crystal structures of 2-6 and 10 were studied by single-crystal X-ray diffraction analysis. On the basis of the crystal structures, solution studies, and DFT calculations, a possible mechanism for CO2 fixation and transformation is given. PMID:17492732

Chen, Jia-Mei; Wei, Wei; Feng, Xiao-Long; Lu, Tong-Bu

2007-06-01

85

Purification and partial amino acid sequence analysis of the cellular tumour antigen, p53, from mouse SV40-transformed cells.  

PubMed Central

The cellular tumour antigen p53 is implicated in the transformation process. To compare p53 from transformed cells and their normal counterparts in detail, and so to identify any structural differences that might alter p53 function, requires information on the primary structure of the protein. By making use of immunochemical techniques we have been able to purify nanomole amounts of p53. This was sufficient, using high sensitivity automated gas-phase sequencing techniques to determine the amino acid sequence of two tryptic peptides from p53. Their sequences agree completely with the predicted polypeptide sequence derived from a cloned cDNA for p53 mRNA and provide the first data on the amino acid sequence of p53. A combination of the high sensitivity amino acid sequencing procedures used here and cDNA sequence analysis should provide the complete amino acid sequence of p53. Images Fig. 1. Fig. 2. Fig. 3.

Leppard, K; Totty, N; Waterfield, M; Harlow, E; Jenkins, J; Crawford, L

1983-01-01

86

Predicting subcellular location of apoptosis proteins with pseudo amino acid composition: approach from amino acid substitution matrix and auto covariance transformation  

Microsoft Academic Search

Apoptosis proteins are very important for understanding the mechanism of programmed cell death. Obtaining information on subcellular\\u000a location of apoptosis proteins is very helpful to understand the apoptosis mechanism. In this paper, based on amino acid substitution\\u000a matrix and auto covariance transformation, we introduce a new sequence-based model, which not only quantitatively describes\\u000a the differences between amino acids, but also

Xiaoqing Yu; Xiaoqi Zheng; Taigang Liu; Yongchao Dou; Jun Wang

87

An attempt to channel the transformation of vanillic acid into vanillin by controlling methoxyhydroquinone formation in Pycnoporus cinnabarinus with cellobiose  

Microsoft Academic Search

The effects of adding cellobiose on the transformation of vanillic acid to vanillin by two strains of Pycnoporus cinnabarinus MUCL39532 and MUCL38467 were studied. When maltose was used as the carbon source in the culture medium, very high levels\\u000a of methoxyhydroquinone were formed from vanillic acid. When cellobiose was used as the carbon source and\\/or added to the culture\\u000a medium

L. Lesage-Meessen; M. Haon; M. Delattre; J.-F. Thibault; B. Colonna Ceccaldi; M. Asther

1997-01-01

88

Geophysical images of the Dead Sea Transform in Jordan reveal an impermeable barrier for fluid flow  

Microsoft Academic Search

High-resolutionseismictomography and magneto-telluric (MT) soundings of the shallow crust show strong changes in material properties across the Dead Sea Transform Fault (DST) in the Arava valley in Jordan. 2D inversion results of the MT data indicate that the DST is associated with a strong lateral conductivity contrast of a highly conductive layer at a depth of approximately 1.5 km cut-off

O. Ritter; T. Ryberg; U. Weckmann; A. Hoffmann-Rothe; A. Abueladas; Z. Garfunkel

2003-01-01

89

Fourier transform infrared study on hydrogen bonding species of carboxylic acids in supercritical carbon dioxide with ethanol  

SciTech Connect

Supercritical fluid extraction has been given much attention recently as one of the new separation technologies in the chemical industry. Fourier transform infrared (FTIR) spectroscopy has been used to determine the equilibrium constants of the dimerization for carboxylic acid (acetic acid or palmitic acid) and the amount of hydrogen bonding species between carboxylic acid and ethanol in supercritical CO{sub 2}. Experiments were carried out at 308.2--313.2 K and 10.0--20.0 MPa. The noticeable band was the C{double_bond}O stretching band for carboxylic acid. In the binary system (supercritical CO{sub 2} + carboxylic acid), the equilibrium constants of the dimerization between the carboxylic acid monomer and dimer decrease with increasing pressure and temperature. The equilibrium constants of palmitic acid are larger than those of acetic acid. In a ternary system (supercritical CO{sub 2} + carboxylic acid + ethanol), the amount of hydrogen bonding species between carboxylic acid and ethanol in supercritical CO{sub 2} increases with the increasing mole fraction of added ethanol. Furthermore, the authors confirm that the solubility enhancement by ethanol used as an entrainer in supercritical CO{sub 2} related to the amount of hydrogen bonding species between carboxylic acid and ethanol.

Yamamoto, Morio; Iwai, Yoshio; Nakajima, Taro; Arai, Yasuhiko [Kyushu Univ., Higashi, Fukuoka (Japan). Dept. of Chemical Systems and Engineering

1999-05-06

90

Reduced Oil Accumulation in Cottonseeds Transformed with a Brassica Nonfunctional Allele of a Delta12 Fatty Acid Desaturase (FAD2)  

Microsoft Academic Search

In an effort to better understand the mechanisms that regulate oil accumulation and packaging in seeds, transgenic cotton lines were generated using a Brassica napus nonfunctional delta-12 fatty acid desaturase (FAD2) gene under control of the phaseolin promoter. Seeds of numerous transgenic plant lines had reduced oil content compared with null-segregating siblings or non- transformed seeds. Seed oil content was

Kent D. Chapman; Purnima B. Neogi; Kater D. Hake; Agnes A. Stawska; Thomas R. Speed; Matthew Q. Cotter; David C. Garrett; Thomas Kerby; Charlene D. Richardson; Brian G. Ayre; Supriyo Ghosh; Anthony J. Kinney

2008-01-01

91

Structure-function evolution of the Transforming acidic coiled coil genes revealed by analysis of phylogenetically diverse organisms  

Microsoft Academic Search

BACKGROUND: Examination of ancient gene families can provide an insight into how the evolution of gene structure can relate to function. Functional homologs of the evolutionarily conserved transforming acidic coiled coil (TACC) gene family are present in organisms from yeast to man. However, correlations between functional interactions and the evolution of these proteins have yet to be determined. RESULTS: We

Ivan H Still; Ananthalakshmy K Vettaikkorumakankauv; Anthony DiMatteo; Ping Liang

2004-01-01

92

Mechanisms for chemical transformations of (R,R)-tartaric acid on Cu(110): A first principles study  

NASA Astrophysics Data System (ADS)

Periodic density functional theory calculations are used to systematically investigate, for the first time, the mechanisms for chemical transformations of (R,R)-tartaric acid on a model Cu(110) surface. The overall potential energy surface for the chemical transformations is revealed. The calculations show that the adsorption of the intact biacid molecules of (R,R)-tartaric acid on Cu(110) surface is not strong, but upon adsorption on Cu(110), the biacid molecules will chemically transform immediately, rather than desorb from the surface. It is found that the chemical transformations of (R,R)-tartaric acid on Cu(110) is a thermodynamically favorable process, to produce the monotartrate species, bitartrate species, and H atoms. Kinetically, the initial reaction step is only one O-H bond scission in either one of the COOH group of a biacid molecule of (R,R)-tartaric acid leading to the formation of a monotartrate species and a H atom, which is an almost spontaneous process. The rate-controlling step is the O-H bond scission in the COOH group of a monotartrate species producing a bitartrate species and a H atom. The concerted reaction for simultaneously breaking the two O-H bonds in both COOH groups of a biacid molecule cannot proceed.

Zhang, Ji; Lu, Tao; Jiang, Chen; Zou, Jianwei; Cao, Fengqi; Chen, Yadong

2009-10-01

93

Nordihydroguaiaretic acid inhibits transforming growth factor ? type 1 receptor activity and downstream signaling  

PubMed Central

It has been well documented that nordihydroguaiaretic acid (NDGA), a phenolic lignan isolated from the creosote bush, Larrea tridentate, has anti-cancer activity in vitro and in vivo. Several mechanisms have been identified that could contribute to these actions, as NDGA directly inhibits metabolic enzymes and receptor tyrosine kinases that are established anti-cancer targets. In the present study, we show that NDGA inhibits the transforming growth factor ? (TGF-?) type I receptor, a serine threonine kinase receptor. In cultured cells, NDGA treatment repressed Smad2 phosphorylation induced by TGF-? treatment and by a constitutively active mutant of TGF-? type I receptor (T202D). NDGA also inhibited downstream transcriptional activation mediated by both TGF-? treatment and the constitutively active mutant receptor. In vitro, NDGA inhibited TGF-? type I receptor mediated Smad2 phosphorylation in crude cell lysates and in a purified preparation. Importantly, screening select analogs demonstrated that modification of NDGA’s structure resulted in altered potency against the receptor. These results indicated that the structure of NDGA can be modified to achieve increased potency. Together our data provide a novel mechanism for NDGA activity which could help explain its anti-cancer activity, and suggest that NDGA could serve as a structural motif for developing serine/threonine kinase inhibitors with selectivity for TGF-? type I receptor.

Li, Fusheng; Anderson, Marc O.; Youngren, Jack F.

2009-01-01

94

Analytical determination of the microbial utilization and transformation of humic acids extracted from municipal refuse.  

PubMed

Humic substances are usually the refractory part of natural organic matter, and in a landfill they can retain inorganic and organic micropollutants. This study has investigated analytically whether humic acids (HA) extracted by use of alkali from either fresh municipal refuse or from refuse disposed of in a landfill for up to 12 months can resist microbial degradation under aerobic conditions. When added as a supplementary nutrient source, up to 63.6% of HA was utilized and this percentage was enhanced to a mean value of 88.5% when different HA preparations were used as the sole source of carbon. In cultures of a soil microbial community containing the same preparations as sole sources of nitrogen, HA was usually completely utilized. The remaining HA re-isolated from some microbial cultures were highly depleted in carbon and, simultaneously, the nitrogen content was enhanced. The FTIR spectra were indicative of strong participation of aliphatic structural units in the refuse-related HA preparations. Because of the microbial activity, different carbonaceous substances were primarily removed from the HA structure, and an increase in nitrogenous molecular groups became apparent. The structural transformations brought about by soil microorganisms "in vitro" corresponded to those occurring naturally in HA obtained from refuse aged for 12 months in a landfill. PMID:11767895

Filip, Z; Berthelin, J

2001-11-01

95

Mevalonic Acid Products as Mediators of Cell Proliferation in Simian Virus 40-transformed 3T3 Cells1  

Microsoft Academic Search

Effects of treatment with serum-free medium and 25-hydroxycholes- terol (2S-OH) on the cell cycle of simian virus 40-transformed 3T3 fibroblasts, designated SV-3T3 cells, were studied and compared with simultaneous effects on the activity of 3-hydroxy-3-methylglutaryl (HMG) CoA reducíase and incorporation of |3H|mevalonic acid into cholesterol, Coenzyme Q, and dolichol. The data confirm our previous finding (O. Larsson and A. Zetterberg,

Olle Larsson; Brht-Marie Johansson

1987-01-01

96

Analytical evaluation of polyunsaturated fatty acids degradation during thermal oxidation of edible oils by Fourier transform infrared spectroscopy  

Microsoft Academic Search

The oxidative deterioration of polyunsaturated fatty acids (PUFAs) in culinary oils and fats during episodes of heating associated with normal usage (80–300°C, 20–40 min) has been monitored by Fourier transform infrared spectroscopy (FTIR). The thermal oxidation of PUFAs is a free radical chain reaction, in which hydroperoxides are generally recognized as the primary major products. Hydroperoxides of PUFAs are easily

M. C. M. Moya Moreno; D. Mendoza Olivares; F. J. Amézquita López; J. V. Gimeno Adelantado; F. Bosch Reig

1999-01-01

97

Soy lecithin phospholipid determination by fourier transform infrared spectroscopy and the acid digest\\/arsenomolybdate method: A comparative study  

Microsoft Academic Search

A study was conducted to determine the accuracy and precision of phospholipid analysis by a simple Fourier transform infrared\\u000a spectroscopy (FTIR) method relative to the conventional phospholipid phosphorus analysis by the acid digest\\/arseno-molybdate\\u000a method by Bartlett. Commercial soy lecithins of known concentrations of phospholipid were prepared and the phospholipid content\\u000a measured by the FTIR and Bartlett methods. The coefficients of

J. M. Nzai; A. Proctor

1999-01-01

98

Polymorphic transformation of L-glutamic acid monitored using combined on-line video microscopy and X-ray diffraction  

NASA Astrophysics Data System (ADS)

Enhancement of process monitoring for detecting transformations of the organic solid state is an important, strategic area currently of substantial interest particularly to the pharmaceutical sector and, more generally, manufacturers of speciality chemical products. A feasibility study is reported in which a solution-mediated polymorphic transformation of L-glutamic acid (LGA) was monitored using, concurrently, both video microscopy accompanied by advanced image processing and, on-line X-ray diffraction. The applicability of these monitoring approaches, applied individually, has been demonstrated previously; however, it was useful to assess the relative sensitivity of the two techniques by their direct comparison, via simultaneous use, during application on-line to monitor a polymorphic transformation process. It was found that the onset of the polymorphic transformation, manifested as the point in time when crystals of the ? phase of LGA were first detected, was elucidated as being significantly sooner via video microscopy. This reflects the fact that the concentration regimes of maximum sensitivity for the individual approaches are complementary, hence video microscopy provides considerable added-value allowing detection of the early stages of the transformation process. Currently, the upper bound on solids concentration that is compatible with extracting useful information about the phase composition using video microscopy, based on particle shape, is restricted. However, it is anticipated that improvements to both the experimental design and the image processing algorithms applied will substantially increase this upper bound allowing practical application under realistic processing conditions.

Dharmayat, Spoorthi; Calderon de Anda, Jorge; Hammond, Robert B.; Lai, Xaiojun; Roberts, Kevin J.; Wang, Xue Z.

2006-08-01

99

Gene expression changes in BALB/3T3 transformants induced by poly(L-lactic acid) or polyurethane films.  

PubMed

We performed DNA microarray analysis on two BALB/3T3 transformants (A5 and A6) induced by polyurethane (PU) film, two (L11 and L21) induced by biodegradable poly(L-lactic acid) (PLLA) film, and the parental cells. The transforming ability of the cells was in the order A5 < A6 < L21 < L11. In all, 1176 cancer-related genes were up- or down-regulated in at least one transformant. Those that were markedly up-regulated were c-fos protooncogene, FBJ osteosarcoma oncogene B, and Jun oncogene; those markedly down-regulated were pleiotrophin, histidine triad nucleotide-binding protein, protein kinase C iota, and large multifunctional protease 7. A common function of proteins encoded by genes that underwent marked expression changes was bone formation. The genes were c-fos, FBJ osteosarcoma, Jun, pleiotrophin, a disintegrin-like and metalloprotease with TS-1 motif protein 1. This finding was consistent with the tumor formation in the 2-year PLLA or PU subcutaneous implantation into rats. The number of genes that underwent marked expression change in each transformant was consistent with its malignancy. PLLA induced more malignant transformants than PU, especially in relation to osteosarcoma-like gene expression. PMID:14704980

Matsuoka, Atsuko; Tsuchiya, Toshie

2004-02-01

100

Monitoring cellular responses upon fatty acid exposure by Fourier transform infrared spectroscopy and Raman spectroscopy.  

PubMed

We investigated the applicability of FTIR-spectroscopy as a high throughput screening method for detection of biochemical changes in intact liver cells in bulk upon fatty acid exposure. HepG2 cells adapted to serum free (HepG2-SF) growth were exposed to four different fatty acids, three octadecenoic acids, differing in cis/trans-configuration or double bond position (oleic acid, elaidic acid and vaccenic acid) as well as palmitic acid in three days. High throughput FTIR spectroscopic measurements on dried films of intact cells showed spectra with high signal-to-noise ratio and great reproducibility. When applying principal component analysis (PCA) a clear discrimination between fatty acid exposures was observed. Higher levels of triacylglycerides were accumulated in cells exposed to elaidic acid than when exposed to the other fatty acids; the least accumulation appeared to be in cells exposed to palmitic acid. An increased absorption at ~966 cm(-1) corresponding to trans-double bond was detected upon elaidic acid exposure but not upon vaccenic acid exposure. Instead, upon vaccenic acid exposure two new absorption bands were observed at 981 and 946 cm(-1) due to the presence of double bond conjugation. Raman spectroscopy on single cells, with and without treatment by vaccenic acid, confirmed the presence of conjugation. By fatty acid composition analysis, the conjugation was further specified to be conjugated linoleic acid (CLA) isomers. Thus, instead of being preserved as a monounsaturated fatty acid, vaccenic acid was converted into CLA in HepG2 cells. The results demonstrate the applicability of high-throughput FTIR spectroscopy as an explorative method in in vitro systems from which biologically relevant hypotheses can be generated and further investigated. PMID:21347493

Najbjerg, Heidi; Afseth, Nils Kristian; Young, Jette F; Bertram, Hanne C; Pedersen, Mona E; Grimmer, Stine; Vogt, Gjermund; Kohler, Achim

2011-02-24

101

The study of aluminum loss and consequent phase transformation in heat-treated acid-leached kaolin  

SciTech Connect

This study investigates the effect of Al leaching during Fe removal from kaolin to mullite. Heat-treated kaolin was obtained by heating natural kaolin at 400, 500, 600, 700, 800 and 900 deg. C. The heat-treated kaolin was then leached at 100 deg. C with 4 M, 3 M, 2 M, 1 M, 0.2 M solution of H{sub 2}SO{sub 4} and 0.2 M solution of oxalic acid. The dried samples were sintered to 1300 deg. C for 4 h at a heating rate of 10 deg. C min{sup -1}. X-ray diffractometry and differential thermal analysis were used to study the phase transformation of kaolin to mullite. It was found that 700 deg. C is the optimum preheat-treatment temperature to leach out Fe and also Al for both types of the acids used. The majority of the 4 M sulfuric acid-treated kaolins formed the cristobalite phase when sintered. On the other hand, 1 M, 0.2 M sulfuric acid and 0.2 M oxalic acid leached heat-treated kaolin formed mullite and quartz phase after sintering. - Research Highlights: {yields} Preheat-treatment of kaolin improves the leachability of unwanted iron. {yields} The optimum preheat-treatment temperature is 700 deg. C. {yields} Sintered 4 M sulfuric acid-treated kaolin majorly formed the cristobalite phase. {yields} Sintered 0.2 M oxalic acid-treated kaolin formed lesser amorphous silicate phase.

Foo, Choo Thye [Malaysian Nuclear Agency (Nuclear Malaysia) Bangi, Selangor (Malaysia); Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Mahmood, Che Seman [Malaysian Nuclear Agency (Nuclear Malaysia) Bangi, Selangor (Malaysia); Mohd Salleh, Mohamad Amran, E-mail: asalleh@eng.upm.edu.my [Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Chemical Engineering Department, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

2011-04-15

102

Catalytic transformation of alcohols to carboxylic acid salts and H2 using water as the oxygen atom source  

NASA Astrophysics Data System (ADS)

The oxidation of alcohols to carboxylic acids is an important industrial reaction used in the synthesis of bulk and fine chemicals. Most current processes are performed by making use of either stoichiometric amounts of toxic oxidizing agents or the use of pressurized dioxygen. Here, we describe an alternative dehydrogenative pathway effected by water and base with the concomitant generation of hydrogen gas. A homogeneous ruthenium complex catalyses the transformation of primary alcohols to carboxylic acid salts at low catalyst loadings (0.2 mol%) in basic aqueous solution. A consequence of this finding could be a safer and cleaner process for the synthesis of carboxylic acids and their derivatives at both laboratory and industrial scales.

Balaraman, Ekambaram; Khaskin, Eugene; Leitus, Gregory; Milstein, David

2013-02-01

103

Catalytic transformation of alcohols to carboxylic acid salts and H2 using water as the oxygen atom source.  

PubMed

The oxidation of alcohols to carboxylic acids is an important industrial reaction used in the synthesis of bulk and fine chemicals. Most current processes are performed by making use of either stoichiometric amounts of toxic oxidizing agents or the use of pressurized dioxygen. Here, we describe an alternative dehydrogenative pathway effected by water and base with the concomitant generation of hydrogen gas. A homogeneous ruthenium complex catalyses the transformation of primary alcohols to carboxylic acid salts at low catalyst loadings (0.2 mol%) in basic aqueous solution. A consequence of this finding could be a safer and cleaner process for the synthesis of carboxylic acids and their derivatives at both laboratory and industrial scales. PMID:23344447

Balaraman, Ekambaram; Khaskin, Eugene; Leitus, Gregory; Milstein, David

2013-01-06

104

Transforming Growth Factor b2 Promotes Glucose Carbon Incorporation into Nucleic Acid Ribose through the Nonoxidative Pentose Cycle in Lung Epithelial Carcinoma Cells1  

Microsoft Academic Search

The invasive transformation of A-459 lung epithelial carcinoma cells has been linked to the autocrine regulation of malignant phenotypic changes by transforming growth factor b (TGF-b). Here we demonstrate, using stable 13C glucose isotopes, that the transformed phenotype is characterized by decreased CO2 production via direct glucose oxidation but increased nucleic acid ribose synthesis through the nonoxidative reactions of the

Laszlo G. Boros; John S. Torday; Shu Lim; Sara Bassilian; Marta Cascante; Wai-Nang Paul Lee

105

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

106

Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues.  

PubMed

Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and compositions of the oxidation products differed according to the oxidizing agent used. Main products of oxidation by 30% HNO(3) were acetic, glucaric, oxalic and glycolic acids. Applying H(2)O(2)/CuO in alkaline solution, the organic acid yields were remarkably lower with formic, acetic and threonic acids as main products. Gluconic acid was formed instead of glucaric acid throughout. Reaction of a 10% H(2)O(2) solution with sugar beet molasses generated formic and lactic acids mainly. Na(2)S(2)O(8) solutions were very inefficient at oxidizing the residues. Glucose, arabinose and galactose were formed during acidic hydrolysis of malt dust and apple marc. The glucose content reached 0.35 g per gram of residue. Important advantages of the microwave application were lower reaction times and reduced reagent demands. PMID:15607197

Fischer, Klaus; Bipp, Hans-Peter

2005-05-01

107

Transformation through the food chain of Lake Baikal hydrobionts fatty acids  

Microsoft Academic Search

The fatty-acid composition of tissues from Lake Baikal hydrobionts involved in the food chain such as Baikal seals, fish,\\u000a and amphipods was studied. GC–MS detected more than 40 fatty acids with different degrees of unsaturation in tissues of Baikal\\u000a hydrobionts. It was concluded from a comparison of the fatty-acid compositions of tissues from the studied animals that the\\u000a formation mechanism

E. S. Averina; O. Grahl-Nielsen; S. V. Bazarsadueva; L. D. Radnaeva

2011-01-01

108

A broadband Fourier-transform microwave spectrometer with laser ablation source: The rotational spectrum of nicotinic acid  

NASA Astrophysics Data System (ADS)

A chirped pulse Fourier transform microwave spectrometer (CP-FTMW) has been combined with a laser ablation source to investigate the broadband rotational spectra of solid biomolecules in the 6.0-18 GHz region. This technique has been successfully applied to the conformational study of nicotinic acid for which two conformers have been characterized for the first time in the gas phase. The quadrupole hyperfine structure originated by a 14N nucleus has been completely resolved for both rotamers using a LA-MB-FTMW spectrometer.

Mata, S.; Peña, I.; Cabezas, C.; López, J. C.; Alonso, J. L.

2012-10-01

109

Potassium Movement and Transformation in an Acid Soil as Affected by Phosphorus  

Microsoft Academic Search

When P and K fertilizer are applied to soil at the same time, the movement and transformation of K may be affected by P. This study was conducted to quantify the effects of monocalcium phosphate (MCP) co-applied with KCl on the distance of K movement, the con- centration of K in different forms and soil pH change at different distances

Zhenyu Du; Jianmin Zhou; Huoyan Wang; Changwen Du; Xiaoqin Chen

2006-01-01

110

Alkaline phosphatase and an acid arylamidase as marker enzymes for normal and transformed WI-38 cells  

SciTech Connect

A survey of eleven enzyme activity levels in normal and SV40 transformed (VA-13) WI-38 cells revealed that the transformed cell enzymes differed by a quantitative and qualitative change of alkaline phosphatase and a quantitative loss of an arylamidase. Alkaline phosphatase activity was found to be elevated in the transformed cells at confluency but not in log phase cultures. While the arylamidase activity from both normal and transformed WI-38 cells had identical pH optima and K/sub m/ values, the activity was approximately 20 times higher in confluent WI-38 cells than in confluent VA-13 cells. Cytochemical staining techniques for both activities are described that permit identification of fluorescent product within the cells, analysis of activity levels, and separation of cells with high and low activities. Mixtures of WI-38 cells and VA-13 cells separated by flow cytometry on the basis of arylamidase activity were subsequently evaluated for alkaline phosphatase isoenzyme and found to have been simultaneously separated into heat labile and heat stable samples.

Dolbeare, F.; Vanderlaan, M.; Phares, W.

1980-01-01

111

Control of Growth by Picolinic Acid: Differential Response of Normal and Transformed Cells  

Microsoft Academic Search

Picolinic acid reversibly inhibits the growth of cultured cells. Fourteen other pyridine derivatives were ineffective or toxic. Untransformed normal rat kidney (NRK) cells are reversibly arrested in the G1 stage of the growth cycle as shown by cell counts, mitotic index, [3H]thymidine incorporation, and flow microfluorometry. Flow microfluorometry was used to monitor the effects of picolinic acid on numerous other

J. A. Fernandez-Pol; Vincent H. Bono; George S. Johnson

1977-01-01

112

Aristolochic acid induces proximal tubule apoptosis and epithelial to mesenchymal transformation  

Microsoft Academic Search

Aristolochic acid contamination in herbal remedies leads to interstitial fibrosis, tubular atrophy, and renal failure in humans. To study the cellular mechanisms contributing to the pathophysiology of this renal disease, we studied Wistar rats treated with aristolochic acid and measured tubular and interstitial cell proliferation, epithelial\\/mesenchymal cell marker expression, tubular membrane integrity, myofibroblast accumulation, oxidative stress, mitochondrial damage, tubular apoptosis,

A A Pozdzik; I J Salmon; F D Debelle; C Decaestecker; C Van den Branden; D Verbeelen; M M Deschodt-Lanckman; J-L Vanherweghem; J L Nortier

2008-01-01

113

Production of ferulic acid from lignocellulolytic agricultural biomass by Thermobifida fusca thermostable esterase produced in Yarrowia lipolytica transformant.  

PubMed

A gene (axe) encoding the AXE thermostable esterase in Thermobifida fusca NTU22 was cloned into a Yarrowia lipolytica P01g host strain. Recombinant expression resulted in extracellular esterase production at levels as high as 70.94 U/ml in Hinton flask culture broth, approximately 140 times higher than observed in a Pichia pastoris expression system. After 72 h of fermentation by the Y. lipolytica transformant in the fed-batch fermentor, the fermentation broth accumulated 41.11 U/ml esterase activity. Rice bran, wheat bran, bagasse and corncob were used as hydrolysis substrates for the esterase, with corncob giving the best ferulic acid yield. The corncob was incubated with T. fusca xylanase (Tfx) for 12h and then with the AXE esterase for an additional 12h. Ferulic acid accumulated to 396 ?M in the culture broth, a higher concentration than with esterase alone or with Tfx and esterase together for 24 h. PMID:21683590

Huang, Yu-Chun; Chen, Yu-Fen; Chen, Cheng-Yu; Chen, Wei-Lin; Ciou, Yong-Ping; Liu, Wen-Hsiung; Yang, Chao-Hsun

2011-05-30

114

Using radiative transfer models to study the atmospheric water vapor content and to eliminate telluric lines from high-resolution optical spectra  

NASA Astrophysics Data System (ADS)

The Radiative Transfer Model (RTM) and the retrieval algorithm, incorporated in the SCIATRAN 2.2 software package developed at the Institute of Remote Sensing/Institute of Enviromental Physics of Bremen University (Germany), allows to simulate, among other things, radiance/irradiance spectra in the 2400--24 000 Å range. In this work we present applications of RTM to two case studies. In the first case the RTM was used to simulate direct solar irradiance spectra, with different water vapor amounts, for the study of the water vapor content in the atmosphere above Sierra Nevada Observatory. Simulated spectra were compared with those measured with a spectrometer operating in the 8000--10 000 Å range. In the second case the RTM was used to generate telluric model spectra to subtract the atmospheric contribution and correct high-resolution stellar spectra from atmospheric water vapor and oxygen lines. The results of both studies are discussed.

Gardini, A.; Maíz Apellániz, J.; Pérez, E.; Quesada, J. A.; Funke, B.

2013-05-01

115

Modulation of transforming growth factor alpha-dependent expression of epidermal growth factor receptor gene by transforming growth factor beta, triiodothyronine, and retinoic acid.  

PubMed

We have investigated the actions of transforming growth factor (TGF) type alpha on epidermal growth factor (EGF) receptor mRNA expression in MDA-468 human mammary carcinoma cells in serum-free media. We found that exposure of MDA-468 cells to TGF alpha results in elevated levels of EGF receptor mRNA. This increase in mRNA accumulation showed time and dose dependence. Addition of TGF beta 1 enhanced the accumulation of EGF receptor mRNA induced by TGF alpha in a time- and dose-dependent manner. We also found that triiodothyronine at physiological concentrations exerts synergistic control on the action of TGF alpha alone, or in association with TGF beta 1, on EGF receptor mRNA expression. Similarly, retinoic acid treatment also enhanced in a time- and dose-dependent manner the TGF alpha-dependent response of EGF receptor mRNA and acted synergistically with TGF beta 1. The results described here suggest that optimum regulation of EGF receptor gene expression by TGF alpha is a complex process involving synergistic interactions with heterologous growth factors and hormones. PMID:2613750

Fernandez-Pol, J A; Klos, D J; Hamilton, P D

1989-11-01

116

Calculations and measurements of the deuterium tunneling frequency in the propiolic acid-formic acid dimer and description of a newly constructed Fourier transform microwave spectrometer.  

PubMed

The concerted proton tunneling frequency for the propiolic acid-formic acid dimer was calculated using a relaxed ab initio double-well potential in the imaginary-frequency mode of the saddle point, and new measurements were made for the deuterated propiolic acid-formic acid (ProOD-FAOD) isotopologue. It is important to have consistent calculated tunneling frequency values between normal and deuterated isotopologues since parameters can be readily adjusted to get good agreement with one isotopologue. High-resolution rotational spectra of deuterated (ProOD-FAOD) dimer were measured using a newly constructed Fourier Transform microwave spectrometer. The new spectrometer has mirror size: 30 cm in diameter with a radius of curvature of 59 cm and is equipped with multiple-FID data collection (5-10 FID's for each gas pulse). For the deuterated (ProOD-FAOD) isotopologue, 45 rotational lines (a type: 34; b type: 11) were measured in the lowest tunneling states range between 6.5 GHz and 15.5 GHz. With the new high-resolution measurements of the tunneling doublets (b-dipole transitions), the double potential well responsible for the deuterium tunneling was depicted much more precisely. The two tunneling states are separated by 3.48 MHz. The rotational constants obtained in this work are quite helpful for further structure analysis as well. PMID:24007006

Sun, Ming; Wang, Yimin; Carey, Spencer J; Mitchell, Erik G; Bowman, Joel; Kukolich, Stephen G

2013-08-28

117

Calculations and measurements of the deuterium tunneling frequency in the propiolic acid-formic acid dimer and description of a newly constructed Fourier transform microwave spectrometer  

NASA Astrophysics Data System (ADS)

The concerted proton tunneling frequency for the propiolic acid-formic acid dimer was calculated using a relaxed ab initio double-well potential in the imaginary-frequency mode of the saddle point, and new measurements were made for the deuterated propiolic acid-formic acid (ProOD-FAOD) isotopologue. It is important to have consistent calculated tunneling frequency values between normal and deuterated isotopologues since parameters can be readily adjusted to get good agreement with one isotopologue. High-resolution rotational spectra of deuterated (ProOD-FAOD) dimer were measured using a newly constructed Fourier Transform microwave spectrometer. The new spectrometer has mirror size: 30 cm in diameter with a radius of curvature of 59 cm and is equipped with multiple-FID data collection (5-10 FID's for each gas pulse). For the deuterated (ProOD-FAOD) isotopologue, 45 rotational lines (a type: 34; b type: 11) were measured in the lowest tunneling states range between 6.5 GHz and 15.5 GHz. With the new high-resolution measurements of the tunneling doublets (b-dipole transitions), the double potential well responsible for the deuterium tunneling was depicted much more precisely. The two tunneling states are separated by 3.48 MHz. The rotational constants obtained in this work are quite helpful for further structure analysis as well.

Sun, Ming; Wang, Yimin; Carey, Spencer J.; Mitchell, Erik G.; Bowman, Joel; Kukolich, Stephen G.

2013-08-01

118

Adsorption of Amino Acids (Ala, Cys, His, Met) on Zeolites: Fourier Transform Infrared and Raman Spectroscopy Investigations  

NASA Astrophysics Data System (ADS)

Minerals adsorb more amino acids with charged R-groups than amino acids with uncharged R-groups. Thus, the peptides that form from the condensation of amino acids on the surface of minerals should be composed of amino acid residues that are more charged than uncharged. However, most of the amino acids (74%) in today's proteins have an uncharged R-group. One mechanism with which to solve this paradox is the use of organophilic minerals such as zeolites. Over the range of pH (pH 2.66-4.50) used in these experiments, the R-group of histidine (His) is positively charged and neutral for alanine (Ala), cysteine (Cys), and methionine (Met). In acidic hydrothermal environments, the pH could be even lower than those used in this study. For the pH range studied, the zeolites were negatively charged, and the overall charge of all amino acids was positive. The conditions used here approximate those of prebiotic Earth. The most important finding of this work is that the relative concentrations of each amino acid (X=His, Met, Cys) to alanine (X/Ala) are close to 1.00. This is an important result with regard to prebiotic chemistry because it could be a solution for the paradox stated above. Pore size did not affect the adsorption of Cys and Met on zeolites, and the Si/Al ratio did not affect the adsorption of Cys, His, and Met. ZSM-5 could be used for the purification of Cys from other amino acids (Student-Newman-Keuls test, p<0.05), and mordenite could be used for separation of amino acids from each other (Student-Newman-Keuls test, p<0.05). As shown by Fourier transform infrared (FT-IR) spectra, Ala interacts with zeolites through the group, and methionine-zeolite interactions involve the COO, , and CH3 groups. FT-IR spectra show that the interaction between the zeolites and His is weak. Cys showed higher adsorption on all zeolites; however, the hydrophobic Van der Waals interaction between zeolites and Cys is too weak to produce any structural changes in the Cys groups (amine, carboxylic, sulfhydryl, etc.); thus, the FT-IR and Raman spectra are the same as those of solid Cys.

Carneiro, Cristine E. A.; de Santana, Henrique; Casado, Clara; Coronas, Joaquin; Zaia, Dimas A. M.

2011-06-01

119

Natural transformation of Pseudomonas stutzeri by plasmids that contain cloned fragments of chromosomal deoxyribonucleic acid  

Microsoft Academic Search

Natural transformation of plasmids by Pseudomonas stutzeri was found to depend on their bearing inserts of chromosomal DNA. A set of plasmids derived from the nonconjugative broad host range plasmid pSa151 was constructed by integrating various chromosomal DNA fragments into the single EcoR1 site of pSa151. Selection for the kanamycin resistance determined by pSa151 demonstrated that the derivative plasmids were

Curtis A. Carlson; Susan M. Steenbergen; John L. Ingraham

1984-01-01

120

Microbial transformations of ferulic acid by Saccharomyces cerevisiae and Pseudomonas fluorescens.  

PubMed Central

Saccharomyces cerevisiae (dry baker's yeast) and Pseudomonas fluorescens were used to convert trans-ferulic acid into 4-hydroxy-3-methoxystyrene in 96 and 89% yields, respectively. The metabolites were isolated by solid-phase extraction and analyzed by thin-layer chromatography and high-performance liquid chromatography. The identities of the metabolites were determined by 1H- and 13C-nuclear magnetic resonance spectroscopy and by mass spectrometry. The mechanism of the decarboxylation of ferulic acid was investigated by measuring the degree and position of deuterium incorporated into the styrene derivative from D2O by mass spectrometry and by both proton and deuterium nuclear magnetic resonance spectroscopies. Resting cells of baker's yeast reduced ferulic acid to 4-hydroxy-3-methoxyphenylpropionic acid in 54% yield when incubations were under an argon atmosphere.

Huang, Z; Dostal, L; Rosazza, J P

1993-01-01

121

Plant Lectin Can Target Receptors Containing Sialic Acid, Exemplified by Podoplanin, to Inhibit Transformed Cell Growth and Migration  

PubMed Central

Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by ?2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN) is highly O-glycosylated with ?2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing ?2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL) with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

Shen, Yongquan; Acharya, Nimish K.; Han, Min; McNulty, Dean E.; Hasegawa, Hitoki; Hyodo, Toshinori; Senga, Takeshi; Geng, Jian-Guo; Kosciuk, Mary; Shin, Seung S.; Goydos, James S.; Temiakov, Dmitry; Nagele, Robert G.; Goldberg, Gary S.

2012-01-01

122

Acid Gas - Diethanolamine Vapor - Liquid Equilibrium Data by Fourier Transform Infrared Spectroscopy  

Microsoft Academic Search

A new apparatus for establishing vapor-liquid equilibrium (VLE) and a new method for measuring VLE data on acid gas - diethanolamine (DEA) systems are described. The acid gases studied were carbon dioxide (CO_2 ) and hydrogen sulfide (H_2S). The capability of the apparatus to establish an equilibrium was verified by reproducing data for CO_ {2}-water and H_2S -water systems. The

Richard Eugene Frazier

1993-01-01

123

Synthesis of gem-dideuterated tetradecanoic acids and their use in investigating the enzymatic transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid.  

PubMed

We report the preparation of the deuterated tetradecanoic acids [2,2,3,3-(2)H(4)]-, [2,2,3,3,10,10-(2)H(6)]-, and [2,2,3,3,13,13-(2)H(6)]-tetradecanoic acids (1, 2, and 3, respectively) and their use to investigate the mechanism of the enzymatic transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid. Probes 2 and 3 were prepared from intermediate ketones 7 and 10, which were transformed into the labeled bromides 17 and 18 by reduction with NaBD(4), tosylation of the resulting alcohol, replacement of the tosyloxy group by deuteride with LiAlD(4), hydrolysis, and reaction with N-bromosuccinimide. The resulting bromides were converted into the alpha-acetylenic esters 21 and 22, respectively, and the additional deuterium labels were introduced by reduction of the conjugated triple bond with Mg in deuterated methanol. The same sequence of reactions starting with 11-bromoundecane afforded 27. Saponification of the labeled esters 23, 24, and 27 gave the deuterated acids 2, 3, and 1, respectively. The results of the biochemical experiments showed that C10-H removal, but not elimination of C13-H, was sensitive to deuterium substitution in the transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid, which is consistent with the hypothesis that this desaturase reaction involves a first slow, C10-H bond cleavage, with probable formation of an unstable allylic intermediate, followed by a second fast C13-H bond removal and concomitant rearrangement. PMID:11722204

Rodríguez, S; Camps, F; Fabriàs, G

2001-11-30

124

Application of Fourier transform infrared spectroscopy for monitoring short-chain free fatty acids in Swiss cheese.  

PubMed

Short-chain free fatty acids (FFA) are important sources of cheese flavor and have been reported to be indicators for assessing quality. The objective of this research was to develop a simple and rapid screening tool for monitoring the short-chain FFA contents in Swiss cheese by using Fourier transform infrared spectroscopy (FTIR). Forty-four Swiss cheese samples were evaluated by using a MIRacle three-reflection diamond attenuated total reflectance (ATR) accessory. Two different sampling techniques were used for FTIR/ATR measurement: direct measurement of Swiss cheese slices (approximately 0.5 g) and measurement of a water-soluble fraction of cheese. The amounts of FFA (propionic, acetic, and butyric acids) in the water-soluble fraction of samples were analyzed by gas chromatography-flame ion-ization detection as a reference method. Calibration models for both direct measurement and the water-soluble fraction of cheese were developed based on a cross-validated (leave-one-out approach) partial least squares regression by using the regions of 3,000 to 2,800, 1,775 to 1,680, and 1,500 to 900 cm(-1) for short-chain FFA in cheese. Promising performance statistics were obtained for the calibration models of both direct measurement and the water-soluble fraction, with improved performance statistics obtained from the water-soluble extract, particularly for propionic acid. Partial least squares models generated from FTIR/ATR spectra by direct measurement of cheeses gave standard errors of cross-validation of 9.7 mg/100 g of cheese for propionic acid, 9.3 mg/100 g of cheese for acetic acid, and 5.5 mg/100 g of cheese for butyric acid, and correlation coefficients >0.9. Standard error of cross-validation values for the water-soluble fraction were 4.4 mg/100 g of cheese for propionic acid, 9.2 mg/100 g of cheese for acetic acid, and 5.2 mg/100 g of cheese for butyric acid with correlation coefficients of 0.98, 0.95, and 0.92, respectively. Infrared spectroscopy and chemometrics accurately and precisely predicted the short-chain FFA content in Swiss cheeses and in the water-soluble fraction of the cheese. PMID:17638969

Koca, N; Rodriguez-Saona, L E; Harper, W J; Alvarez, V B

2007-08-01

125

Transformation of 3,5-dimethoxy,4-hydroxy cinnamic acid by polyphenol oxidase from the fungus Trametes versicolor: product elucidation studies.  

PubMed

Sinapic acid (SA), 3,5-dimethoxy,4-hydroxy cinnamic acid, was incubated with a crude polyphenol oxidase from the fungus Trametes versicolor. Some products of this transformation were isolated and their structures identified using mass spectrometry, nuclear magnetic resonance and Fourier transform infrared spectroscopy, and X-ray crystallography. It was found that the enzymatic oxidation of SA includes two distinct phases. In the initial phase SA is enzymatically transformed to r-1H-2c,6c-bis-(4'-hydroxy-3', 5'-dimethoxyphenyl)-3,7-dioxabicyclo-[3,3,0]-octane-4,8-dione, dehydrodisinapic acid dilactone. The mechanism of this reaction may involve coupling of two phenoxy radicals by the beta-beta mode and subsequent intramolecular nucleophilic attack. In the second phase dehydrodisinapic acid dilactone is transformed by polyphenol oxidase into several intermediate products, including 4-(4-(3, 5-dimethoxy-4-oxo-2,5-cyclohexadienyliden)-1, 4-dihydroxy-(E)-2-butenylidene)-2,6-dimethoxy-2, 5-cyclohexadien-1-one. The final product of the overall transformation of SA is 2,6-dimethoxy-p-benzoquinone. The obtained results were used to propose a part of the transformation pathway for the enzymatic oxidation of SA by polyphenol oxidase. PMID:10099249

Lacki, K; Duvnjak, Z

1998-03-20

126

Chemically Transformable Configurations of Mercaptohexadecanoic Acid Self-Assembled Monolayers Adsorbed on Au(111)  

SciTech Connect

Carboxyl-terminated self-assembled monolayers (SAMs) are commonly used in a variety of applications, with the assumption that the molecules form well-ordered monolayers. In this work, near-edge X-ray absorption fine structure measurements verify that well-ordered monolayers can be formed using acetic acid in the solvent. Disordered monolayers with unbound molecules present in the film result using only ethanol. A stark reorientation occurs upon deprotonation of the end group by rinsing in a KOH solution. This reorientation of the end group is reversible with tilted-over, hydrogen-bound carboxyl groups while the carboxylate ion end groups are upright. C(1s) photoemission shows that SAMs formed and rinsed with acetic acid in ethanol have protonated end groups, while SAMs formed without acetic acid have a large fraction of carboxylate-terminated molecules.

Willey, Trevor M.; Vance, Andy L.; Van Buuren, T; Bostedt, C; Nelson, Arthur J.; Terminello, L J.; Fadley, C S.

2004-03-30

127

Transformations of diphenylphosphinothioic acid tertiary amides mediated by directed ortho metallation.  

PubMed

ortho-Lithiation of N,N-diisopropyl-P,P-diphenylphosphinothioic amide using n-BuLi in the presence of TMEDA in diethyl ether followed by electrophilic trapping is described as an efficient method for the synthesis of ortho-functionalised derivatives in high yields. The structural modification of the phosphinothioic amide includes C-X (X = P, S, Si, Sn, I) and C-C bond forming reactions with a large variety of electrophiles. Additional applications based on functional group transformations are also reported. They include imine formation, desulfurization and Suzuki cross-coupling reactions on selected compounds. PMID:22733007

el Hajjouji, Hajar; Belmonte, Eva; García-López, Jesús; Fernández, Ignacio; Iglesias, María José; Roces, Laura; García-Granda, Santiago; El Laghdach, Anas; López Ortiz, Fernando

2012-06-25

128

Transformation of 1-Menthene by a Cladosporium: Accumulation of ?-Isopropyl Glutaric Acid in the Growth Medium  

PubMed Central

An organism isolated from soil samples collected near a terpene plant grew in the presence of 1-menthene, with no other major source of carbon and energy. The organism was tentatively identified as a member of the genus Cladosporium. When this organism was grown in the presence of 1-menthene, with no other major source of carbon, substantial quantities of ?-isopropyl glutaric acid accumulated in the fermentation medium. ?-Isopropyl glutaric acid is probably an end product of the degradation of 1-menthene by the organism.

Mukherjee, Barid B.; Kraidman, Gary; Hill, Ira D.

1974-01-01

129

CHEMICAL TRANSFORMATION MODULES FOR EULERIAN ACID DEPOSITION MODELS. VOLUME 1. THE GAS-PHASE CHEMISTRY  

EPA Science Inventory

This study focuses on the review and evaluation of mechanistic and kinetic data for the gas-phase reactions that lead to the production of acidic substances in the environment. A master mechanism is designed that treats oxides, sulfur dioxide, ozone, hydrogen peroxide, ammonia, t...

130

CHEMICAL TRANSFORMATION MODULES FOR EULERIAN ACID DEPOSITION MODELS. VOLUME 2. THE AQUEOUS-PHASE CHEMISTRY  

EPA Science Inventory

This study focuses on the review and evaluation of mechanistic and kinetic data for aqueous-phase reactions that lead to the production of acidic substances in the environment. The intent of this research is to provide a framework that can be used to develop a state-of-the-art aq...

131

Microbial degradation and transformation of humic acids from permanent meadow and forest soils  

Microsoft Academic Search

Humic acids (HAs) extracted from two soils under permanent meadow, and from a forest soil, were added as either a supplemental source of nutrients, or as the sole sources of carbon or nitrogen to cultures of microbial communities indigenous to the same soil, and incubated under semi-aerobic conditions for 12 months. Depending on nutrient conditions in the individual cultures and

Zdenek Filip; Marta Tesa?ová

2004-01-01

132

Untersuchung einer Methode zur Bestimmung von Blei, Cadmium, Quecksilber, Arsen und Tellur in Lebensmitteln mit Hilfe der Röntgenfluorescenzanalyse  

Microsoft Academic Search

The decomposition of food of animal origin with a mixture of nitric acid and sulphuric acid in a polyethylene flask at 60° C and with nitric acid in a steel vessel at 150° C was investigated. Both procedures give satisfactory results. The advantage of the second procedure lies in the small amounts of reagents needed, thus keeping blank values low.

H. Menke; Johannes Gutenberg-Universitfit; Fachbereich Chemie

1977-01-01

133

Bowman-Birk protease inhibitor and its palmitic acid conjugate prevent 7,12-dimethylbenz[ a]anthracene-induced transformation in cultured mouse mammary glands  

Microsoft Academic Search

The chemopreventive effects of Bowman-Birk protease inhibitor (BBI), a soybean polypeptide, and its palmitic acid conjugate, Pal-BBI, on 7,12-dimethylbenz[a]anthracene (DMBA)-induced transformation were investigated by using an in vitro whole organ culture system of mouse mammary glands. The transformation incidence was measured as the number of glands containing nodule-like alveolar lesions (NLAL). Both BBI and Pal-BBI were effective in preventing DMBA-induced

Xiantang Du; Karin Beloussow; Wei-Chiang Shen

2001-01-01

134

Effect of temperature on oxidative transformation of perfluorooctanoic acid (PFOA) by persulfate activation in water  

Microsoft Academic Search

Perfluorooctanoic acid (PFOA) is an emerging environmental pollutant attracting significant attention due to its global distribution, high persistence, and bioaccumulation properties. In this study, the degradation of aqueous PFOA at different temperatures was examined using heat-activated persulfate. Using this approach, 93.5% of PFOA was degraded after 30h at 85°C with 43.6% of F? yield, and the shorter chain length compounds

C. S. Liu; C. P. Higgins; F. Wang; K. Shih

135

Determining milk isolated and conjugated trans-unsaturated fatty acids using fourier transform Raman spectroscopy.  

PubMed

The feasibility of Raman spectroscopy in combination with partial least-squares (PLS) regression for the determination of individual or grouped trans-monounsaturated fatty acids (trans-MUFA) and conjugated linoleic acids (CLA) in milk fat is demonstrated using spectra obtained at two temperature conditions: room temperature and after freezing at -80 °C. The PLS results displayed capability for direct semiroutine quantification of several individual CLA (cis-9,trans-11 and trans-10,cis-12 C18:2) and trans-MUFA (trans-4-15 C18:1) in minor concentrations (below 1.0 g/100 g of milk fat). Calibration models were based on reference data cross-correlation or determined by specific scattering signals in the Raman spectra. Distinct bands for trans-MUFA (1674 cm(-1)) and CLA (1653 cm(-1)) from the trans isolated and cis,trans conjugated C ? C bonds were identified, as well as original evidence for the temperature effect (new bands, peak shifts, and higher intensities) on the Raman spectra of fatty acid methyl ester and triacylglyceride standards, are supplied. PMID:22084940

Stefanov, Ivan; Baeten, Vincent; Abbas, Ouissam; Colman, Ellen; Vlaeminck, Bruno; De Baets, Bernard; Fievez, Veerle

2011-12-05

136

Structural transformation of hemicelluloses and lignin from triploid poplar during acid-pretreatment based biorefinery process.  

PubMed

In order to understand the behaviors of hemicelluloses and lignin under the given acidic conditions with increasing severity, the structural characteristics were elucidated in detail by both wet chemistry methods and spectroscopic analyses in this study. Although acidic pretreatment significantly hydrolyzed the glycosidic linkages in xylan backbone and then reduced the molecular weight of xylan from 89,600 to 19,630 g/mol, a slightly increased amount of glucuronic acid was observed, probably attributing to the maintenance of ester bonds. The serious structural variation occurred in lignin macromolecule was evidenced by the extensive degradation of ?-O-4 ether linkages and resinol substructure, together with the changes in the ratios of the three monolignols in ester-bond, ether-bond and non-condensed phenolic compounds. At the most severity, obvious condensation reactions introduced the clear shift of C(2) and C(5) correlations and the absence of C(6) correlation in guaiacyl units by 2D HSQC analysis. PMID:22609662

Wang, Kun; Yang, Haiyan; Yao, Xi; Xu, Feng; Sun, Run-Cang

2012-04-19

137

Insights into the photochemical transformation of iodine in aqueous systems: humic acid photosensitized reduction of iodate.  

PubMed

Marine aerosol is highly enriched in iodine, mostly in the form of iodate (IO(3)(-)) ions, compared to its relative abundance in seawater. This paper describes a laboratory study of the photochemical reduction of IO(3)(-) in the presence of humic acid. Spectroscopic analysis showed that ~20% of IO(3)(-) was converted to "free" iodide (I(-)) ions and this fraction remained constant as a function of time. Direct detection of an organically fixed fraction (i.e., ? 80%) was not possible, but a number of test reactions with surrogate organic compounds containing functional groups identified in humic acid structures indicate that efficient substitution of iodine occurs at aromatic 1,2 diol sites. These iodinated humic acids are stable with respect to photolysis at near-UV/visible wavelengths and are likely to account for a significant proportion of the soluble iodine-containing organic material occurring within aerosols. In the lower atmosphere, oxidation of I(-) to I(2) in marine aerosol occurs mostly through the uptake of O(3), with H(2)O(2) playing a very minor role. A model of iodine chemistry in the open ocean tropical boundary layer, which incorporates these experimental results, is able to account for the observed enrichment of iodine in marine aerosol. PMID:23038990

Saunders, Russell W; Kumar, Ravi; MacDonald, Samantha M; Plane, John M C

2012-10-17

138

Structural transformation of apocytochrome c induced by alternating copolymers of maleic acid and alkene.  

PubMed

Apocytochrome c interacts with two copolymers: poly(isobutylene-alt-maleic acid) (PIMA) and poly(1-tetradecene-alt-maleic acid) (PTMA). The interaction leads to apocytochrome c, a conformational change from random coil to alpha-helical structure. The alpha-helix content is influenced by the copolymer concentration, the length of alkyl chain of the copolymers, and pH of the medium. The electrostatic attraction between the copolymer and protein is an indispensable factor for the folding of the protein at acid pH. The hydrophobic interaction is an important factor over the entire pH range, especially when both the copolymer and protein carry negative charges at alkaline pH. The electrostatic and hydrophobic attractions between the copolymer and protein exclude water molecules, promoting the formation of hydrogen bonds within the helical structure. On the other hand, the hydrogen bonds formed between the ionized carboxyl of the copolymer and the amide of the protein partly restrain the formation of hydrogen bonds within the helical structure when the copolymer concentration is higher at pH 6.5 and 10.5. PMID:16153115

Liang, Li; Yao, Ping; Jiang, Ming

139

Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of Acid sphingomyelinase.  

PubMed

Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome-destabilizing experimental anticancer agent siramesine inhibits ASM by interfering with the binding of ASM to its essential lysosomal cofactor, bis(monoacylglycero)phosphate. Like siramesine, several clinically relevant ASM inhibitors trigger cancer-specific lysosomal cell death, reduce tumor growth in vivo, and revert multidrug resistance. Their cancer selectivity is associated with transformation-associated reduction in ASM expression and subsequent failure to maintain sphingomyelin hydrolysis during drug exposure. Taken together, these data identify ASM as an attractive target for cancer therapy. PMID:24029234

Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line; Ellegaard, Anne-Marie; Bilgin, Mesut; Redmer, Susanne; Ostenfeld, Marie S; Ulanet, Danielle; Dovmark, Tobias H; Lønborg, Andreas; Vindeløv, Signe D; Hanahan, Douglas; Arenz, Christoph; Ejsing, Christer S; Kirkegaard, Thomas; Rohde, Mikkel; Nylandsted, Jesper; Jäättelä, Marja

2013-09-01

140

Mutagenic Action, Loss of Transforming Activity, and Inhibition of Deoxyribonucleic Acid Template Activity In Vitro Caused by Chemical Linkage of Carcinogenic Polycyclic Hydrocarbons to Deoxyribonucleic Acid  

PubMed Central

In a solvent system of 10?2m phosphate buffer (pH 6.8)-ethanol (2:1, v/v) and in an iodine-induced reaction, the polycyclic hydrocarbons [3H]3,4-benzpyrene and [3H]3,4-BP/[3H]9, 10-dimethyl-1,2-benzanthracene (DMBA) can be covalently linked to deoxyribonucleic acid (DNA) at room temperature. By stepwise addition of the hydrocarbon and repeating the reaction two to three times after isolating the hydrocarbon DNA adduct, it was possible to introduce as many as one covalently bound hydrocarbon molecule per 100 nucleotide bases. When 3,4-BP and DMBA were linked in this way to biologically active transforming DNA of Bacillus subtilis, they caused (i) reduction of the transforming activity of the DNA accompanied by (ii) significant increases in the frequency of forward mutations. The majority of these hydrocarbon-induced mutations were not able to revert spontaneously. These samples of DNA covalently linked with hydrocarbons showed much lower levels of survival of biological activity when assayed in recipient strains (hcr?) which are known to be deficient in the enzymes required for repair of ultraviolet light-induced damage to DNA. 3,4-BP covalently linked to calf thymus DNA at a level of approximately one hydrocarbon molecule per 330 bases was shown to cause up to 80% inhibition of the in vitro transcription of the DNA by highly purified ribonucleic acid polymerase prepared from Micrococcus luteus under the experimental condition of template saturation. The presence of 3,4-BP and DMBA molecules covalently bound to B. subtilis DNA samples was also found to prevent complete denaturation of the bihelical structure of certain DNA molecules and thus appears to effect a cross-link in these DNA molecules.

Maher, Veronica M.; Lesko, Stephen A.; Straat, Patricia A.; Ts'O, Paul O. P.

1971-01-01

141

No activation of new initiation points for deoxyribonucleic acid replication in BALB/c 3T3 cells transformed by Kirsten sarcoma virus  

SciTech Connect

BALB/c 3T3 cells were transformed by Kirsten sarcoma virus, and five clones were isolated in soft agar. Average replicon sizes of the transformed cell lines were stimated by the method of fiber-autoradiography and found to be the same size as the nontransformed 3T3 cells, analyzed in parallel. The results indicate that, unlike simian virus 40 and Epstein-Barr virus, Kirsten sarcoma virus does not activate new initiation points for cellular deoxyribonucleic acid replication in murine sarcome virus-transformed BALB/c 3T3 cells.

Oppenheim, A.; Horowitz, A.T.

1981-08-01

142

Laser-Stark and Fourier-transform spectroscopy of the. nu. /sub 3/ band of monodeuterated fromic acid, HCOOD  

SciTech Connect

The ..nu../sub 3/ fundamental band of monodeuterated formic acid, HCOOD, at 5.64 ..mu..m has been studied by using a combination of CO-laser-Stark spectroscopy and high-resolution Fourier-transform spectroscopy. The analysis of the Fourier-transform data, together with all previous pure rotational ground-state data, gave precise values for the ..nu../sub 3/-band origin and rotational and centrifugal distortion parameters. Slightly refined ground-state parameters were also obtained. A c-type Coriolis interaction between ..nu../sub 3/ and ..nu../sub 6/+..nu../sub 7/ was included in the analysis resulting in a value for the interaction parameter and for some effective parameters of the perturbing state. A second weaker Coriolis interaction between ..nu../sub 3/ and ..nu../sub 5/+..nu../sub 9/ was noted but not analyzed. The Stark data yielded precise values for the ..mu../sub a/ and ..mu../sub b/ dipole-moment components in the ground and excited states.

Nemes, L.; McKellar, A.R.W.; Johns, J.W.C.

1987-07-01

143

Analytical evaluation of polyunsaturated fatty acids degradation during thermal oxidation of edible oils by Fourier transform infrared spectroscopy.  

PubMed

The oxidative deterioration of polyunsaturated fatty acids (PUFAs) in culinary oils and fats during episodes of heating associated with normal usage (80-300 degrees C, 20-40 min) has been monitored by Fourier transform infrared spectroscopy (FTIR). The thermal oxidation of PUFAs is a free radical chain reaction, in which hydroperoxides are generally recognized as the primary major products. Hydroperoxides of PUFAs are easily decomposed into a very complex mixture of secondary products with the decrease in unsaturation. The oxidative advance of PUFAs during heating was studied by the determination of unsaturation percentage at different temperatures and heating times. Oils frequently used in food frying such as olive oil, sunflower oil, corn oil and seeds oil (sunflower, safflower and canola seed) were studied. The results show there is a decrease in unsaturation starting at 150 degrees C and becoming more pronounced at temperatures around 250 degrees C. The following variations were found in the unsaturation percentage, expressed as methyl linoleate, between the original sample and the sample heated at 300 degrees C for 40 min: olive oil (19-6%), sunflower oil (29-12%), corn oil (28-18%) and seeds oil (23-11%). This variation in unsaturation grade provides evidence of the transformation of essential PUFAs and subsequent decrease in the oils' nutritional value. The internal standard method is suitably precise when the n-valeronitrile is used as standard as shown by the 1-2% relative standard deviation (R.S.D.) found for seven replicates. PMID:18967717

Moya Moreno, M C; Mendoza Olivares, D; Amézquita López, F J; Gimeno Adelantado, J V; Bosch Reig, F

1999-09-13

144

Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain  

PubMed Central

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects.

Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

2012-01-01

145

Single amino acid (arginine) deprivation: rapid and selective death of cultured transformed and malignant cells  

PubMed Central

The effects of arginine deprivation (–Arg) has been examined in 26 cell lines. Less than 10% of those with transformed or malignant phenotype survived for > 5 days, and many died more rapidly, notably leukaemic cells. Bivariate flow cytometry confirmed that vulnerable cell lines failed to move out of cell cycle into a quiescent state (G0), but reinitiated DNA synthesis. Many cells remained in S-phase, and/or had difficulty progressing through to G2 and M. Two tumour lines proved relatively ‘resistant’, A549 and MCF7. Although considerable cell loss occurred initially, both lines showed a ‘cell cycle freeze’, in which cells survived for > 10 days. These cells recovered their proliferative activity in +Arg medium, but behaved in the same manner to a second –Arg episode as they did to the first episode. In contrast, normal cells entered G0 and survived in –Arg medium for several weeks, with the majority of cells recovering with predictable kinetics in +Arg medium. In general, cells from a wide range of tumours and established lines die quickly in vitro following –Arg treatment, because of defective cell cycle checkpoint stringency, the efficacy of the treatment being most clearly demonstrated in co-cultures in which only the normal cells survived. The findings demonstrate a potentially simple, effective and non-genotoxic strategy for the treatment of a wide range of cancers. © 2000 Cancer Research Campaign

Scott, L; Lamb, J; Smith, S; Wheatley, D N

2000-01-01

146

Q-mode curve resolution of UV-vis spectra for structural transformation studies of anthocyanins in acidic solutions.  

PubMed

Chemometric analysis of ultraviolet-visible (UV-vis) spectra for pH values 1.0, 3.3, 5.3, and 6.9 was used to investigate the kinetics and the structural transformations of anthocyanins in extracts of calyces of hibiscus flowers of the Hibiscus acetosella Welw. ex Finicius for the first time. Six different species were detected: the quinoidal base (A), the flavylium cation (AH+), the pseudobase or carbinol pseudobase (B), cis-chalcone (C(C)), trans-chalcone (C(t)), and ionized cis-chalcone (C(C)-). Four equilibrium constant values were calculated using relative concentrations, hydration, pK(h) = 2.60 +/- 0.01, tautomeric, K(T) = 0.14 +/- 0.01, acid-base, pK(a) = 4.24 +/- 0.04, and ionization of the cis-chalcone, pK(C(C)) = 8.74 +/- 1.5 x 10(-2). The calculated protonation rate of the tautomers is K(H+) = 0.08 +/- 7.6 x 10(-3). These constants are in excellent agreement with those measured previously in salt form. From a kinetic viewpoint, the situation encountered is interesting since the reported investigation is limited to visible light absorption in acid medium. These models have not been reported in the literature. PMID:17386538

Março, Paulo Henrique; Scarminio, Ieda Spacino

2006-10-04

147

Identification of acidic NSO compounds in crude oils of different geochemical origins by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry  

Microsoft Academic Search

We present the selective ionization, resolution and identification of acidic NSO compounds in three crude oils of different geochemical origins by negative ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Selective ionization by ESI affords direct detection of neutral nitrogen compounds and carboxylic acids in petroleum without pre-chromatographic isolation. Ultra-high resolution\\/mass accuracy allows detailed and

Christine A Hughey; Ryan P Rodgers; Alan G Marshall; Kuangnan Qian; Winston K Robbins

2002-01-01

148

Acidic and neutral polar NSO compounds in Smackover oils of different thermal maturity revealed by electrospray high field Fourier transform ion cyclotron resonance mass spectrometry  

Microsoft Academic Search

Negative ion electrospray ionization (ESI) coupled with high field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) allows for the direct detection of acidic NSO compounds in petroleum. The technique requires no chromatographic separation, is able to distinguish 18 different compound classes (e.g., neutral nitrogen, carboxylic acids and oxygenates), and can identify ?14,000 distinct masses by ultra-high mass resolution and

Christine A Hughey; Ryan P Rodgers; Alan G Marshall; Clifford C Walters; Kuangnan Qian; Paul Mankiewicz

2004-01-01

149

Protonation States of Membrane-Embedded Carboxylic Acid Groups in Rhodopsin and Metarhodopsin II: A FourierTransform Infrared Spectroscopy Study of Site-Directed Mutants  

Microsoft Academic Search

A method was developed to measure Fourier-transform infrared (FTIR) difference spectra of detergent-solubilized rhodopsin expressed in COS cells. Experiments were performed on native bovine rhodopsin, rhodopsin expressed in COS cells, and three expressed rhodopsin mutants with amino acid replacements of membrane-embedded carboxylic acid groups: Asp-83 --> Asn (D83N), Glu-122 --> Gln (E122Q), and the double mutant D83N\\/E122Q. Each of the

Karim Fahmy; Frank Jager; Mareike Beck; Tatyana A. Zvyaga; Thomas P. Sakmar; Friedrich Siebert

1993-01-01

150

Analysis of Milk Odd- and Branched-Chain Fatty Acids Using Fourier Transform (FT)-Raman Spectroscopy.  

PubMed

Fourier transform (FT)-Raman spectra of pure C13:0, C15:0, C17:0, iso C14:0, iso C15:0, and ante C15:0 fatty acid methyl ester standards (FAMESs) and 75 milk fat samples from 6 different dietary experiments were acquired at room temperature (RT) and immediately after freezing at -80 °C (FT). The latter generally included much more well-defined and sharper scattering bands than those obtained at RT. Further, the spectra at FT revealed additional acuate bands in the vicinity of peculiar wavenumber regions, as well as an increase of Raman scattering intensity, which was sometimes associated with a shift of the peak. Partial least-squares (PLS) regression models based on either selected regions or the full spectra and using two pretreatment methods [multiplicative scatter correction (MSC, using raw spectra of milk fat only) and modified MSC (MMSC, a combination of pure FAMESs and milk fat spectra)] with cross-validation were used to evaluate the different types of milk fat FT-Raman spectra for the predictions of individual odd- and branched-chain fatty acids (OBCFAs) and their sums. In general, most individual (C15:0, ante C15:0, iso C17:0, and ante C17:0) and grouped (ODD, ANTE, and total OBCFAs) fatty acids were favorably (coefficient of determination, R(2) > 0.65) predicted using models with FT spectra only or a combination of RT and FT spectra (RFT), when compared to models with spectra analyzed at RT only. The results indicate the interest to use FT-Raman spectra collected at different temperatures for the prediction of narrow concentrations of saturated OBCFAs in milk fat. PMID:20886895

Stefanov, I; Baeten, V; Abbas, O; Colman, E; Vlaeminck, B; De Baets, B; Fievez, V

2010-10-01

151

Phase transformations in sulfuric acid aerosols: Implications for stratospheric ozone depletion  

SciTech Connect

Activation reactions of benign chlorine species (HCl, CIONO{sub 2}) on aerosols in the winter polar stratosphere set the stage for the spring-time catalytic destruction of ozone leading to the Antarctic ozone hole. Field observations have demonstrated the existence of both solid and liquid particles consisting of H{sub 2}SO{sub 4}, HNO{sub 3}, and H{sub 2}O. The exact freezing conditions and final composition of the solid aerosols remain the subject of investigations. We present laboratory observations of isolated individual sulfuric acid/water particles under stratospheric temperatures and water vapor pressures. Our experiments demonstrate that this binary system would not freeze unless temperatures were below the water-ice frost point. Upon freezing, we observe H{sub 2}SO{sub 4}{minus}8H{sub 2}O, not the generally invoked H{sub 2}SO{sub 4}{minus}4H{sub 2}O. We suggest that the water-rich octahydrate phase is likely to be one of the high relative humidity forms which is efficient in chlorine activation.{copyright} 1997 American Geophysical Union

Imre, D.G. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States); Xu, J. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)]|[Institute of Terrestrial and Planetary Atmospheres, State University of , New York 11794 (United States); Tridico, A.C. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)

1997-01-01

152

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as hindered'' amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 {times} 10{sup 14} BTU/yr.

Bullin, J.A.; Frazier, R.E.

1991-09-01

153

Fourier transform infrared (FTIR) spectroscopic study of acid soluble collagen and gelatin from skins and bones of young and adult Nile perch ( Lates niloticus)  

Microsoft Academic Search

Fourier transform infrared (FTIR) spectroscopy was conducted on type A gelatins derived from skins and bones of young and adult Nile perch (Lates niloticus) by a sequential extraction process. Spectra for gelatins were compared to each other and to that of acid soluble collagen from young Nile perch skins, in order to elucidate changes in protein secondary structure during collagen

J. H Muyonga; C. G. B Cole; K. G Duodu

2004-01-01

154

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.

155

Direct determination of rosmarinic acid in Lamiaceae herbs using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and chemometrics.  

PubMed

For the determination of rosmarinic acid (RA) directly in pulverized plant material, a method is developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) without any physicochemical pretreatment of samples. The RA content of 11 samples of eight different Lamiaceae herbs, as determined by high performance liquid chromatography (HPLC), varied between 86 ± 1 mg/g (in lemon balm) and 12.0 ± 0.8 mg/g (in hyssop) of dried plant material. The 11 samples and 50 other additional samples, which were prepared by mixing initial samples with KBr, were measured using DRIFTS. The second derivative of the spectral region 1344-806 cm(-1) was used and the corresponding data were analyzed using partial least squares (PLS) regression. The correlation between infrared spectral analysis and HPLC measurements shows that the DRIFTS method is sufficiently accurate, simple, and rapid. The RA content of the 11 Lamiaceae samples determined by DRIFTS ranged from 81 ± 4 mg/g (in lemon balm) to 12 ± 3 mg/g (in hyssop) of dried plant material. PMID:23496773

Saltas, Dimitrios; Pappas, Christos S; Daferera, Dimitra; Tarantilis, Petros A; Polissiou, Moschos G

2013-03-22

156

Allenic derivatives of nucleic acid components and their transformation products: a new class of biologically active nucleoside analogues.  

PubMed

Reaction of adenine (1a) or cytosine (1b) with excess 1,4-dichloro-2-butyne catalyzed by K2CO3 in (CH3)2SO gave the 4-chloro-2-butynyl derivatives 2a and 2b. The latter were converted to the 4-hydroxy-2-butynyl compounds 3a and 3b by refluxing in 0.1 M HCl. Isomerization of 3a in 0.1 M NaOH at 100 degrees C for 1 h gave an equilibrium mixture of 3a and allene 4a. Pure 4a was obtained by column chromatography. Similarly, compound 3b was transformed/0.1 M NaOH, 20% aq. dioxane, 9 h, 100 degrees C/ to a mixture of 3b and 4b from which pure 4b was obtained by chromatography and crystallization. By contrast, reflux of 3a or 3b in 1 M NaOH in 50% aq. dioxane for 1 h afforded cyclized products - dihydrofuryl derivatives 5a and 5b. Hydrogenation of 4a and 5a gave 9-(4-hydroxybutyl)adenine (6a) and 9-(tetrahydro-2-furyl)adenine (7a), respectively. Scope and limitations of allenic isomerization in nucleic acid base series, spectroscopy and biological activity of the obtained products will be discussed. PMID:3697137

Phadtare, S; Zemlicka, J

1987-01-01

157

Thrombospondin-1-induced smooth muscle cell chemotaxis and proliferation are dependent on transforming growth factor-?2 and hyaluronic acid synthase.  

PubMed

Angioplasty causes local vascular injury, leading to the release of thrombospondin-1 (TSP-1), which stimulates vascular smooth muscle cell (VSMC) migration and proliferation, important steps in the development of intimal hyperplasia. Transforming growth factor beta 2 (TGF-?2) and hyaluronic acid synthase (HAS) are two pro-stenotic genes upregulated in VSMCs by TSP-1. We hypothesized that inhibition of TGF-?2 or HAS would inhibit TSP-1-induced VSMC migration, proliferation, and TSP-1 signaling. Our data demonstrate that Inhibition of either TGF-?2 or HAS inhibited TSP-1-induced VSMC migration and proliferation. Activation of ERK 1 was decreased by TGF-?2 inhibition and unaffected by HAS inhibition. TGF-?2 and HAS are not implicated in TSP-1-induced thbs1 expression, while they are each implicated in TSP-1-induced expression of their own gene. In summary, TSP-1-induced VSMC migration and proliferation rely on intact TGF-?2 signaling and HAS function. TSP-1 activation of ERK 1 is dependent on TGF-?2. These data further expand our understanding of the complexity of TSP-1 cellular signaling and the involvement of TGF-?2 and HAS. PMID:24104451

Stein, Jeffrey J; Iwuchukwu, Chinenye; Maier, Kristopher G; Gahtan, Vivian

2013-10-09

158

Use of a cloned multidrug resistance gene for coamplification and overproduction of major excreted protein, a transformation-regulated secreted acid protease  

SciTech Connect

Malignantly transformed mouse fibroblasts synthesize and secrete large amounts of major excreted protein (MEP), a 39,000-dalton precursor to an acid protease (cathepsin L). To evaluate the possible role of this protease in the transformed phenotype, the authors transfected cloned genes for mouse or human MEP into mouse MIH 3T3 cells with an expression vector for the dominant, selectable human multidrug resistance (MDR1) gene. The cotransfected MEP sequences were efficiently coamplified and transcribed during stepwise selection for multidrug resistance in colchicine. The transfected NIH 3T3 cell lines containing amplified MEP sequences synthesized as much MEP as did Kirsten sarcoma virus-transformed NIH 3T3 cells. The MEP synthesized by cells transfected with the cloned mouse and human MEP genes were also secreted. Elevated synthesis and secretion of MEP by NIH 3T3 cells did not change the nontransformed phenotype of these cells.

Kane, S.E.; Troen, B.R.; Gal, S.; Ueda, K.; Pastan, I.; Gottesman, M.M.

1988-08-01

159

Effects of short-term acid and aluminum exposure on the parr-smolt transformation in Atlantic salmon (Salmo salar): Disruption of seawater tolerance and endocrine status  

USGS Publications Warehouse

Episodic acidification resulting in increased acidity and inorganic aluminum (Ali) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either control (pH 6.7-6.9) or acid/Al (pH 5.4-6.3, 28-64 ??g l-1 Ali) conditions for 2 and 5 days, and impacts on freshwater (FW) ion regulation, seawater (SW) tolerance, plasma hormone levels and stress response were examined. Gill Al concentrations were elevated in all smolts exposed to acid/Al relative to controls confirming exposure to increased Ali. There was no effect of acid/Al on plasma ion concentrations in FW however, smolts exposed to acid/Al followed by a 24 h SW challenge exhibited greater plasma Cl- levels than controls, indicating reduced SW tolerance. Loss of SW tolerance was accompanied by reductions in gill Na+,K+-ATPase (NKA) activity and Na+,K+,2Cl- (NKCC) cotransporter protein abundance. Acid/Al exposure resulted in decreased plasma insulin-like growth factor (IGF-I) and 3,3???,5???-triiodo-l-thyronine (T3) levels, whereas no effect of treatment was seen on plasma cortisol, growth hormone (GH), or thyroxine (T4) levels. Acid/Al exposure resulted in increased hematocrit and plasma glucose levels in FW, but both returned to control levels after 24 h in SW. The results indicate that smolt development and SW tolerance are compromised by short-term exposure to acid/Al in the absence of detectable impacts on FW ion regulation. Loss of SW tolerance during short-term acid/Al exposure likely results from reductions in gill NKA and NKCC, possibly mediated by decreases in plasma IGF-I and T3. ?? 2008 Elsevier Inc.

Monette, M. Y.; Bjornsson, B. T.; McCormick, S. D.

2008-01-01

160

Prolonged exposure to acid and bile induces chromosome abnormalities that precede malignant transformation of benign Barrett's epithelium  

PubMed Central

Abstract Barrett’s esophagus (BE) is an asymptomatic, pre-malignant condition of the esophagus that can progress to esophageal adenocarcinoma (EAC). BE arises typically in individuals with long-standing gastroesophageal reflux disease (GERD). The neoplastic progression of BE has been extensively studied histologically and defined as a metaplasia- dyplasia- carcinoma sequence. However the genetic basis of this process is poorly understood. It is conceived that preclinical models of BE may facilitate discovery of molecular markers due to ease of longitudinal sampling. Clinical markers to stratify the patients at higher risk are vital to institute appropriate therapeutic intervention since EAC has very poor prognosis. We developed a dynamic in-vitro BE carcinogenesis (BEC) model by exposing naïve Barrett’s epithelium cell line (BAR-T) to acid and bile at pH4 (B4), 5min/day for a year. The BEC model acquired malignant characteristics after chronic repeated exposure to B4 similar to the sequential progression of BE to EAC in vivo. Aim To study cytogenetic changes during progressive transformation in the BEC model. Results We observed that the BAR-T cells progressively acquired several chromosomal abnormalities in the BEC model. Evidence of chromosomal loss (-Y) rearrangements [t(10;16) and dup (11q)] and clonal selection appeared during the early stages of the BEC model. Clonal selection resulted in a stabilized monoclonal population of cells that had a changed morphology and formed colony in soft agar. BAR-T cells grown in parallel without any exposure did not show any of these abnormalities. Conclusions Prolonged acid and bile exposure induced chromosomal aberrations and clonal selection in benign BAR-T cells. Since aneuploidy preceded morphological/dysplastic changes in the BEC model, chromosomal aberrations may be an early predictor of BE progression. The [t(10;16) and dup(11q)] aberrations identified in this study harbor several genes associated with cancer and may be responsible for neoplastic behavior of cells. After further validation, in-vivo, they may be clinically useful for diagnosis of BE, progressing to dysplasia/esophageal adenocarcinoma.

2012-01-01

161

Decreased Rubisco activity leads to dramatic changes of nitrate metabolism, amino acid metabolism and the levels of phenylpropanoids and nicotine in tobacco antisense RBCS transformants.  

PubMed

Tobacco transformants that express an antisense RBCS construct were used to investigate the consequences of a lesion in photosynthetic carbon metabolism for nitrogen metabolism and secondary metabolism. The results show that an inhibition of photosynthesis and decrease in sugar levels leads to a general inhibition of nitrogen metabolism, and dramatic changes in the levels of secondary metabolites. The response was particularly clear in plants that received excess nitrogen. In these conditions, a decrease of Rubisco activity led to an inhibition of nitrate reductase activity, accumulation of nitrate, a decrease of amino acid levels that was larger than the decrease of sugars, and a large decrease of chlorogenic acid and of nicotine, which are the major carbon- and nitrogen-rich secondary metabolites in tobacco leaves, respectively. Similar changes were seen when nitrogen-replete wild-type tobacco was grown in low light. The inhibition of nitrogen metabolism was partly masked when wild-type plants and antisense RBCS transformants were compared in marginal or in limiting nitrogen, because the lower growth rate of the transformants alleviated the nitrogen deficiency, leading to an increase of amino acids. In these conditions, chlorogenic acid always decreased but the decrease of nicotine was ameliorated or reversed. When the changes in internal pools are compared across all the genotypes and growth conditions, two conclusions emerge. First, decreased levels of primary metabolites lead to a dramatic decrease in the levels of secondary metabolites. Second, changes of the amino acid : sugar ratio are accompanied by changes of the nicotine:chlorogenic acid ratio. PMID:12061898

Matt, Petra; Krapp, Anne; Haake, Volker; Mock, Hans-Peter; Stitt, Mark

2002-06-01

162

Determination of thermally induced trans-fatty acids in soybean oil by attenuated total reflectance fourier transform infrared spectroscopy and gas chromatography analysis.  

PubMed

The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 °C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm(-1) of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 °C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment. PMID:23025355

Li, An; Ha, Yiming; Wang, Feng; Li, Weiming; Li, Qingpeng

2012-10-12

163

RNase mapping of intact nucleic acids by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) and 18O labeling  

Microsoft Academic Search

We present a method using 18O labeling and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) for characterizing intact ribonucleic acids (RNAs) and their posttranscriptional modifications. An 18O label is incorporated at the 3?-phosphate end of oligonucleotides upon hydrolysis of RNAs with RNase T1. The 18O-labeled digestion products are then identified without prior separation by ESI-FTICRMS. The combination

Zhaojing Meng; Patrick A. Limbach

2004-01-01

164

Salvianolic acid B reverses the epithelial-to-mesenchymal transition of HK-2 cells that is induced by transforming growth factor-?  

Microsoft Academic Search

Salvianolic acid B (Sal B) is the most abundant bioactive molecule from Radix Salviae Miltiorrhizae, and has recently been used for treating renal fibrosis in traditional Chinese medicine. Here we investigated the ability\\u000a reversal of Sal B to reverse the transdifferentiation of human kidney proximal tubular epithelial cells that was induced by\\u000a transforming growth factor-beta 1 (TGF-?1). The effects of

Rong-hua Pan; Feng-yan Xie; Hui-mei Chen; Li-zhi Xu; Xiao-chun Wu; Ling-ling Xu; Gang Yao

2011-01-01

165

Effects of A^TV-Dimethylformamideand Retinoic Acid on Transforming Growth Factor\\/? Induced Mitogenesis in AKR-2B Mouse Embryo Fibroblasts1  

Microsoft Academic Search

Transforming growth factor-\\/? (TGF-\\/3) is a (»functional reagent which can exert both stimulatory and inhibitory effects upon the same target cell. Treatment of growth arrested AKR-2B mouse embryo fibroblasts with TGF-\\/S has been shown to stimulate mitogenesis by an indirect mechanism. Addition of the differentiation agents ,V,Y-dimetli)Iform- amide (DMF) or retinoic acid simultaneously with TGF-\\/3 blocked the ability of TGF-0

Alan E. Levine; Craig A. Crandall

166

Determination of free fatty acids in crude palm oil and refined-bleached-deodorized palm olein using fourier transform infrared spectroscopy  

Microsoft Academic Search

A rapid direct Fourier transform infrared (FTIR) spectroscopic method using a 100 BaF2 transmission cell was developed for the determination of free fatty acid (FFA) in crude palm oil (CPO) and refined-bleached-deodorized\\u000a (RBD) palm olein, covering an analytical range of 3.0–6.5% and 0.07–0.6% FFA, respectively. The samples were prepared by hydrolyzing\\u000a oil with enzyme in an incubator. The optimal calibration

Y. B. Che Man; M. H. Moh; F. R. van de Voort

1999-01-01

167

Ground-based nitric acid measurements at Arrival Heights, Antarctica, using solar and lunar Fourier transform infrared observations  

Microsoft Academic Search

Nitric acid plays an important role in processes leading to stratospheric ozone loss in polar regions. Spectroscopic absorption measurements of nitric acid have been made during the sunlit part of the Antarctic year at Arrival Heights (78°S, 167°E) since the late 1980s. This paper presents the first extension of these nitric acid measurements through the winter, using the Moon as

S. W. Wood; R. L. Batchelor; A. Goldman; C. P. Rinsland; B. J. Connor; F. J. Murcray; T. M. Stephen; D. N. Heuff

2004-01-01

168

Conditions Affecting the Isolation from Transformed Cells of Bacillus subtilis of High-Molecular-Weight Single-Stranded Deoxyribonucleic Acid of Donor Origin  

PubMed Central

The deoxyribonucleic acid (DNA) extraction procedure of Piechowska and Fox was evaluated to determine which steps are required for the isolation of high-molecular-weight single-stranded material from transformed cultures of Bacillus subtilis. The results indicate that high-molecular-weight single-stranded DNA can be isolated when certain basic proteins are present at the time of lysis. In the absence of such protective agents as lysozyme or cytC the single-stranded DNA is degraded. The single-stranded DNA can also be protected by being treated with lysozyme at low temperature. The high molecular weight of this single-stranded material and its kinetics of appearance are consistent with its being an intermediate in the transformation process.

Davidoff-Abelson, R.; Dubnau, D.

1973-01-01

169

Identification of weak and strong organic acids in atmospheric aerosols by capillary electrophoresis/mass spectrometry and ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

A novel approach using a combination of capillary electrophoresis/mass spectrometry (CE/MS) and off-line Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) revealed the structural details of acidic constituents of atmospheric organic aerosol. Both techniques utilized electrospray ionization (ESI), a soft ionization method, to facilitate the analysis of complex mixtures of organic compounds. CE/ESI-MS using an UltraTrol LN-precoated capillary and acidic background electrolytes at different pH values (2.5 and 4.7) was used to differentiate between weak (carboxylic) and strong (sulfonic) organic acids. On the basis of the electrophoretic mobility, m/z constraints from CE/ESI(-)-MS, and elemental composition information retrieved from off-line FTICR-MS, a variety of aliphatic and aromatic carboxylic acids (CHO-bearing molecules), nitrogen-containing carboxylic acids (CHON-bearing molecules), organosulfates (CHOS-bearing molecules), and (nitrooxy)organosulfates (CHONS-bearing molecules) were tentatively identified in the Oasis-HLB-extracted urban PM(2.5) (particulate matter with an aerodynamic diameter of <2.5 ?m). The chemical known/unknown structures of detected compounds were confirmed by the semiempirical Offord model (effective mobility linearly correlated to Z/M(2/3)). The majorities of the identified compounds are products of atmospheric reactions and are known contributors to secondary organic aerosols. PMID:22770380

Yassine, Mahmoud M; Dabek-Zlotorzynska, Ewa; Harir, Mourad; Schmitt-Kopplin, Philippe

2012-07-24

170

Sodium-stimulated amino acid uptake into isolated membrane vesicles from Balb/c 3T3 cells transformed by simian virus 40.  

PubMed Central

Mediated uptake of amino acids by membrane vesicles isolated from Balb/c 3T3 cells transformed by simian virus 40 has been demonstrated. Initial rates of transport of radioactively labeled L-leucine and alpha-aminoisobutyric acid were enhanced by the addition of NaCl (100 mM) to the reaction mixture at the start of the uptake process. This enhancement included a prominent "overshoot" during initial uptake. Slight stimulation of alpha-aminoisobutyric acid uptake was seen with K+, but none with Li+. The mediated nature of the uptake event for L-leucine was shown by saturation kinetics and by inhibition with L-valine. The transport assay measured predominantly intravesicular amino acid uptake rather than binding, as shown by the variation of uptake in response to changes in extravesicular osmolarity. Electron microscopy confirmed the presence of closed vesicles. Thus, amino acid transport has been characterized in an in vitro membrane vesicles system which should prove useful for studies of growth control. Images

Quinlan, D C; Parnes, J R; Shalom, R; Garvey, T Q; Isselbacher, K J; Hochstadt, J

1976-01-01

171

Removal of diclofenac and mefenamic acid by the white rot fungus Phanerochaete sordida YK-624 and identification of their metabolites after fungal transformation.  

PubMed

The non-steroidal anti-inflammatory drugs diclofenac (DCF) and mefenamic acid (MFA) were treated with the white rot fungus Phanerochaete sordida YK-624. DCF completely disappeared and MFA decreased by about 90% after 6 days of treatment. It was also confirmed that the fungus almost completely removed the acute lethal toxicity of DCF and MFA towards the freshwater crustacean Thamnocephalus platyurus after 6 days of treatment. Mass spectrometric and (1)H nuclear magnetic resonance analyses demonstrated that two mono-hydroxylated DCFs (4'-hydroxydiclofenac and 5-hydroxydiclofenac) and one di-hydroxylated DCF (4',5-dihydroxydiclofenac) were formed via fungal transformation. The four metabolites of MFA were identified as 3'-hydroxymethylmefenamic acid (mono-hydroxylated MFA), 3'-hydroxymethyl-5-hydroxymefenamic acid (di-hydroxylated MFA), 3'-hydroxymethyl-6'-hydroxymefenamic acid (di-hydroxylated MFA) and 3'-carboxymefenamic acid. These results suggest that hydroxylation catalyzed by cytochrome P450 (CYP) in P. sordida YK-624 may be involved in the elimination and detoxification of DCF and MFA. This notion was further supported by the fact that smaller decreases in DCF and MFA were observed in cultures of P. sordida YK-624 incubated with 1-aminobenzotriazole, a known inhibitor of CYP. PMID:20127144

Hata, Takayuki; Kawai, Shingo; Okamura, Hideo; Nishida, Tomoaki

2010-02-02

172

Oligomerization of 2-methylpropene and transformation of 2,4,4-trimethyl-2-pentene over supported and unsupported perfluorinated resinsulfonic acid catalysts  

SciTech Connect

Oligomerization of 2-methylpropene was studied with two types of supported (on alumina and on silicon carbide) as well neat perfluorinated resinsulfonic acid catalysts. The heterogeneous reactions were carried out over the solid acid catalysts in a continuous flow reactor at temperatures between 85 and 170 C under atmospheric pressure. Under the studied conditions (85 to 105 C, 1 atm pressure, WHSV:1-3 g/g {center dot} h) all catalysts studied are suitable for oligomerization of 2-methyl-propene. Product distributions show regular temperature dependence: upon increasing temperature the molecular weight of oligomers decreases, with no difference in the selectivity of the catalysts. Transformation of 2,4,4-trimethyl-2-pentene in the liquid phase at room temperature shows surprising selectivity using either the hydrated or dehydrated forms of the resinsulfonic acids. In the case of the hydrated forms of the acids, only double bond isomerization takes place. With dehydrated acids oligomerization as well as isomerization occurs. Above 50 C the selectivity is lost.

Bucsi, I.; Olah, G.A. (Univ. of Southern California, University Park, Los Angeles (United States))

1992-09-01

173

Transformation ofEscherichia coli withPlasmid Deoxyribonucleic Acid: Calcium-Induced Binding of Deoxyribonucleic AcidtoWholeCells andtoIsolated MembraneFractions  

Microsoft Academic Search

Plasmid deoxyribonucleic acid(DNA)was tightly boundtocellsofEscherichia coli at0°Cinthepresenceofdivalent cations. During incubation at42°C, 0.1to 1% ofthis DNA becameresistant todeoxyribonuclease. Deoxyribonuclease-re- sistant DNA binding andtheability toproduce transformants becamesaturated whentransformation mixtures contained 1to2ugofplasmid NTP16DNA and about 5x 10' viable cells. Underoptimumconditions, between 1and2molecule equivalents of3H-labeled NTP16DNA perviable cell becamedeoxyribonuclease resistant. Despite this, only0.1to1%ofviable cells becametransformed by saturating amountsoftheplasmid. Theresults suggest thattransport ofDNA acrosstheinner membraneisa

A. WESTON; M. G. M. BROWN; H. R. PERKINS; J. R. SAUNDERS

1981-01-01

174

Fourier-transform infra-red studies of the alkaline isomerization of mitochondrial cytochrome c and the ionization of carboxylic acids.  

PubMed Central

The alkaline transitions of tuna and horse ferricytochromes c and the trifluoroacetyl-lysine derivative of horse ferricytochrome c have been studied by Fourier-transform (FT) i.r. spectroscopy. The spectral perturbations resulting from the transition have been interpreted by reference to FT i.r. data on simple carboxylic-acid-containing compounds and a bacterial cytochrome c551 in which a haem propionate ionizes without causing a significant conformational change. The analysis strongly suggests that ionization of a haem propionate of mitochondrial cytochrome c triggers the alkaline conformation change.

Tonge, P; Moore, G R; Wharton, C W

1989-01-01

175

Presence of Nitrosospira cluster 2 bacteria corresponds to N transformation rates in nine acid Scots pine forest soils  

Microsoft Academic Search

The relation between environmental factors and the presence of ammonia-oxidising bacteria (AOB), and its consequences for the N transformation rates were investigated in nine Scots pine (Pinus sylvestris L.) forest soils. In general, the diversity in AOB appears to be strikingly low compared to other ecosystems. Nitrosospira cluster 2, as determined by temporal temperature gradient electrophoresis and sequencing, was the

R. A. Nugroho; W. F. M. Röling; A. M. Laverman; H. R. Zoomer; H. A. Verhoef

2005-01-01

176

Lactic Acid Is Elevated in Idiopathic Pulmonary Fibrosis and Induces Myofibroblast Differentiation via pH-Dependent Activation of Transforming Growth Factor-?  

PubMed Central

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex disease for which the pathogenesis is poorly understood. In this study, we identified lactic acid as a metabolite that is elevated in the lung tissue of patients with IPF. Objectives: This study examines the effect of lactic acid on myofibroblast differentiation and pulmonary fibrosis. Methods: We used metabolomic analysis to examine cellular metabolism in lung tissue from patients with IPF and determined the effects of lactic acid and lactate dehydrogenase-5 (LDH5) overexpression on myofibroblast differentiation and transforming growth factor (TGF)-? activation in vitro. Measurements and Main Results: Lactic acid concentrations from healthy and IPF lung tissue were determined by nuclear magnetic resonance spectroscopy; ?-smooth muscle actin, calponin, and LDH5 expression were assessed by Western blot of cell culture lysates. Lactic acid and LDH5 were significantly elevated in IPF lung tissue compared with controls. Physiologic concentrations of lactic acid induced myofibroblast differentiation via activation of TGF-?. TGF-? induced expression of LDH5 via hypoxia-inducible factor 1? (HIF1?). Importantly, overexpression of both HIF1? and LDH5 in human lung fibroblasts induced myofibroblast differentiation and synergized with low-dose TGF-? to induce differentiation. Furthermore, inhibition of both HIF1? and LDH5 inhibited TGF-?–induced myofibroblast differentiation. Conclusions: We have identified the metabolite lactic acid as an important mediator of myofibroblast differentiation via a pH-dependent activation of TGF-?. We propose that the metabolic milieu of the lung, and potentially other tissues, is an important driving force behind myofibroblast differentiation and potentially the initiation and progression of fibrotic disorders.

Kottmann, Robert Matthew; Kulkarni, Ajit A.; Smolnycki, Katie A.; Lyda, Elizabeth; Dahanayake, Thinesh; Salibi, Rami; Honnons, Sylvie; Jones, Carolyn; Isern, Nancy G.; Hu, Jian Z.; Nathan, Steven D.; Grant, Geraldine; Phipps, Richard P.

2012-01-01

177

Lactic Acid is Elevated in Idiopathic Pulmonary Fibrosis and Induces Myofibroblast Differentiation Via pH-Dependent Activation of Transforming Growth Factor-?  

SciTech Connect

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex disease for which the pathogenesis is poorly understood. In this study, we identified lactic acid as a metabolite that is elevated in the lung tissue of patients with IPF. Objectives: This study examines the effect of lactic acid on myofibroblast differentiation and pulmonary fibrosis. Methods:We used metabolomic analysis to examine cellular metabolism in lung tissuefrom patients with IPFanddeterminedthe effects of lactic acid and lactate dehydrogenase-5 (LDH5) overexpression on myofibroblast differentiation and transforming growth factor (TGF)-b activation in vitro. Measurements and Main Results: Lactic acid concentrations from healthy and IPF lung tissue were determined by nuclear magnetic resonance spectroscopy; a-smooth muscle actin, calponin, and LDH5 expression were assessed by Western blot of cell culture lysates. Lactic acid and LDH5 were significantly elevated in IPF lung tissue compared with controls. Physiologic concentrations of lactic acid induced myofibroblast differentiation via activation of TGF-b. TGF-b induced expression of LDH5 via hypoxia-inducible factor 1a (HIF1a). Importantly, overexpression of both HIF1a and LDH5 in human lung fibroblasts induced myofibroblast differentiation and synergized with low dose TGF-b to induce differentiation. Furthermore, inhibition of both HIF1a and LDH5 inhibited TGF-b–induced myofibroblast differentiation. Conclusions: We have identified the metabolite lactic acid as an important mediator of myofibroblast differentiation via a pHdependent activation of TGF-b. We propose that the metabolic milieu of the lung, and potentially other tissues, is an important driving force behind myofibroblast differentiation and potentially the initiation and progression of fibrotic disorders.

Kottman, R. M.; Kulkarni, Ajit A.; Smolnycki, Katie A.; Lyda, Elizabeth; Dahanayake, Thinesh; Salibi, Rami; Honnons, Sylvie; Jones, Carolyn; Isern, Nancy G.; Hu, Jian Z.; Nathan, Steven D.; Grant, Geraldine; Phipps, Richard P.; Sime, Patricia J.

2012-10-15

178

A rapid method for the quantification of fatty acids in fats and oils with emphasis on trans fatty acids using fourier transform near infrared spectroscopy (FT-NIR)  

Microsoft Academic Search

A rapid method was developed for classifying and quantifying the FA composition of edible oils and fats using Fourier Transform\\u000a near infrared spectroscopy (FT-NIR). The FT-NIR spectra showed unique fingerprints for saturated FA, cis and trans monounsaturated FA, and all n?6 and n?3 PUFA within TAG to permit qualitative and quantitative comparisons of fats and oils.\\u000a The quantitative models were

Hormoz Azizian; John K. G. Kramer

2005-01-01

179

Q-mode curve resolution of UV–vis spectra for structural transformation studies of anthocyanins in acidic solutions  

Microsoft Academic Search

Chemometric analysis of ultraviolet–visible (UV–vis) spectra for pH values 1.0, 3.3, 5.3, and 6.9 was used to investigate the kinetics and the structural transformations of anthocyanins in extracts of calyces of hibiscus flowers of the Hibiscus acetosella Welw. ex Finicius for the first time. Six different species were detected: the quinoidal base (A), the flavylium cation (AH+), the pseudobase or

Paulo Henrique Março; Ieda Spacino Scarminio

2007-01-01

180

D-Alpha-tocopherol acid polyethylene glycol 1000 succinate, an effective stabilizer during solidification transformation of baicalin nanosuspensions.  

PubMed

Baicalin nanosuspensions, stabilized with 10% TPGS (relative to the weight of baicalin), were transformed into nanosuspensions powders by solidification process. Solidification methods for this transformation included freeze-drying, spray drying or vacuum drying. High pressure homogenization was applied for production of baicalin nanosuspensions used TPGS, SDS, P188, HPMC and MC as stabilizer, respectively. The influence of the different solidification transformation methods on the redispersibility of solid drug nanosuspensions was systemically investigated, such as freeze-drying, spray drying and vacuum drying. Each method was applied with three grades of process stresses called as "conservative", "moderate" and "aggressive" conditions, and the redispersibility index (RDI) of nanosuspensions stabilized by stabilizers (such as TPGS, SDS, P188, HPMC and MC) during those process was investigated. The results showed that there was significant difference in RDI of nanosuspensions after solidification process. The RDI(a) (1.09, 1.01, 1.05, 0.99), RDI(b) (1.03, 0.99, 1.06, 1.02) and RDI(c) (1.01, 1.01, 1.09, 1.08) of nanosuspensions stabilized by TPGS were more small during different solidification process, compared with those of nanosuspensions stabilized by other stabilizer. It was concluded that the baicalin nanosuspensions were subjected to agglomeration or crystal growth during solidification transformation, especially at high aggressive stress conditions. Meanwhile, compared to other stabilizer, the TPGS was more effective for stability of baicalin nanosuspensions, which could exhibit higher affinity to the drug crystal and stronger surface adsorption at different solidification stresses. PMID:23291447

Yue, Peng-Fei; Wan, Jing; Wang, Yong; Li, Yu; Ma, Yue-Qin; Yang, Ming; Hu, Peng-Yi; Yuan, Hai-Long; Wang, Chang-Hong

2013-01-03

181

Rate of aerobic nitrogen transformations in six acid climax forest soils and the effect of phosphorus and CaCO3  

SciTech Connect

Nitrogen transformations (mineralization, nitrification, and nitrous oxide production) were evaluated in acid forest floor soils collected from six climax forest sites on Blackhawk Island, Wisconsin. Soils' acidity (CaCl2) ranged from pH 3.9 to 5.1, and organic matter concentrations varied from 2.4 to 59.0 percent. The samples were incubated aerobically for 4 weeks at 30C under field moist conditions. Treatments were: control; 100 mg P (as KH2PO4) kg soil; CaCO3; and P with CaCO3. Nitrification of mineralized N ranged from nearly complete in the SM Alfisol to almost non-existent in the Histosol. Addition of P had little effect on ammonification or nitrification. Liming, however, greatly enhanced ammonification on nonnitrifying or slowly nitrifying soils and both ammonification and nitrification in nitrifying soils. Adding P and lime together did not affect N transformations compared to liming alone. Nitrous oxide emission rates in the soils were related to nitrification. From 0.03 to 0.3 percent of the NH4-N nitrified was released as N2O-N. Phosphorus addition had little effect but liming increased N2O emission rates in soil where nitrification was also enhanced.

Sahrawat, K.L.; Keeney, D.R.; Adams, S.S.

1985-09-01

182

Modulation of Fourier transform infrared spectra and total sialic acid levels by selenium during 1,2 dimethylhydrazine-induced colon carcinogenesis in rats.  

PubMed

The present study investigated the modulatory potential of selenium supplementation, if any, on Fourier transform infrared (FTIR) spectra in brush border membranes (BBM) of colons and on serum total sialic acid as well as lipid bound sialic acid during 1,2 dimethyl hydrazine (DMH)-induced colorectal carcinogenesis in rats. The FTIR spectra of BBM from the colons of DMH-treated rats revealed a significant increase in the lipid contents but showed a significant decline in the protein contents. Further, decrease in the collagen as well as creatine contents was also noticed in the colons of DMH-treated rats. Supplementation with selenium appreciably restored protein as well as collagen contents and resulted in decreased lipids levels in the colons of DMH-treated rats. Interestingly, a significant increase in the levels of total sialic acid in serum of DMH-treated rats was observed which, however, got moderated significantly upon selenium supplementation. Moreover, no significant changes were observed in the levels of lipid bound sialic acid in all the treated groups as compared to controls. In conclusion, the present study suggested that supplementation of selenium act as a chemopreventive agent and delays considerably the process of colon carcinogenesis. PMID:23368918

Ghadi, Fereshteh Ezzati; Malhotra, Anshoo; Ghara, Abdollah Ramzani; Dhawan, D K

2013-01-01

183

Prediction of humic acid content and respiration activity of biogenic waste by means of Fourier transform infrared (FTIR) spectra and partial least squares regression (PLS-R) models.  

PubMed

Fourier transform infrared (FTIR) spectroscopy has been proven to be an appropriate analytical method for the qualitative assessment of compost stability. This study focuses on quantitative determination of two time-consuming parameters: humic acid (HA) contents and respiration activity. Reactivity/stability and humification were quantified by respiration activities (oxygen uptake) and humic acid contents. These features are also reflected by a specific infrared spectroscopic pattern. Based on this relationship partial least squares regression (PLS-R) models for the prediction of respiration activities and humic acid contents were calculated. Characteristic wavenumber regions that are assigned to the biological/chemical parameter were selected for multivariate data analysis. The coefficient of determination (R(2)) obtained for the humic acid prediction model from infrared spectra was 87% with a root mean square error of cross-validation (RMSECV) of 2.6% organic dry matter (ODM). The prediction model for respiration activity resulted in a R(2) of 94% and a RMSECV for oxygen uptake of 2.9mgg(-1) dry matter (DM). PMID:19071688

Meissl, Katharina; Smidt, Ena; Schwanninger, Manfred

2007-01-09

184

Solvent effects and polymorphic transformation of organic nonlinear optical crystal L-pyroglutamic acid in solution growth processes  

Microsoft Academic Search

Single crystals of a new promising nonlinear optical material for the tunable UV harmonic generation, l-pyroglutamic acid 60×20×20mm3 in size were obtained from aqueous solution by using the temperature-lowering method. Solubility of l-pyroglutamic acid in different solvents was measured. The single crystals showed different morphological characteristics and growth rate in different solvents with different crystallographic orientations. Methanol or ethanol solutions

W. S Wang; M. D Aggarwal; J Choi; T Gebre; Angela D Shields; Benjamin G Penn; Donald O Frazier

1999-01-01

185

Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells  

PubMed Central

The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1?, IL-6 and IL-8), consistent with the sustained activation of NFK? and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation.

Escudero-Lourdes, C; Wu, T; Camarillo, J. M.; Gandolfi, A. J

2011-01-01

186

Reversible transformation between ?-oxo acids and ?-amino acids on ZnS particles: a photochemical model for tuning the prebiotic redox homoeostasis  

NASA Astrophysics Data System (ADS)

How prebiotic metabolic pathways could have formed is an essential question for the origins of life on early Earth. From the abiogenetic point of view, the emergence of primordial metabolism may be postulated as a continuum from Earth's geochemical processes to chemoautotrophic biochemical procedures on mineral surfaces. In the present study, we examined in detail the reversible amination of ?-ketoglutarate on UV-irradiated ZnS particles under variable reaction conditions such as pH, temperature, hole scavenger species and concentrations, and different amino acids. It was observed that the reductive amination of ?-ketoglutarate and the oxidative amination of glutamate were both effectively performed on ZnS surfaces in the presence and absence of a hole scavenger, respectively. Accordingly, a photocatalytic mechanism was proposed. The reversible photochemical reaction was more efficient under basic conditions but independent of temperature in the range of 30-60 °C. SO3 2- was more effective than S2- as the hole scavenger. Finally, we extended the glutamate dehydrogenase-like chemistry to a set of other ?-amino acids and their corresponding ?-oxo acids and found that hydrophobic amino acid side chains were more conducive to the reversible redox reactions. Since the experimental conditions are believed to have been prevalent in shallow water hydrothermal vent systems of early Earth, the results of this work not only suggest that the ZnS-assisted photochemical reaction can regulate the redox equilibrium between ?-amino acids and ?-oxo acids, but also provide a model of how prebiotic metabolic homoeostasis could have been developed and regulated. These findings can advance our understanding of the establishment of archaic non-enzymatic metabolic systems and the origins of autotrophy.

Wang, Wei; Liu, Xiaoyang; Yang, Yanqiang; Su, Wenhui

2013-01-01

187

Agrobacterium tumefaciens -mediated transformation of Lesquerella fendleri L., a potential new oil crop with rich lesquerolic acid  

Microsoft Academic Search

A protocol was developed for regeneration and Agrobacterium-mediated genetic transformation of Lesquerella fendleri. Calli were first induced from hypocotyls and cotyledons on MS plus 0.5 mg l?1 BA, 1 mg l?1 NAA and 1 mg l?1 2,4-D, then co-cultivated for 2–3 days in darkness on MS supplemented with 0.5 mg l?1 BA, 0.2 mg l?1 NAA and 100 ?mol l?1As together with Agrobacterium tumefaciens strain EHA105\\/pCAMBIA1301 that harbored genes for uidA (GUS) and

Wenyan Wang; Chenggang Wang; Bang-Lian Huang; Bangquan Huang

2008-01-01

188

Transformation of 1-Menthene by a Cladosporium: Accumulation of beta-Isopropyl Glutaric Acid in the Growth Medium.  

PubMed

An organism isolated from soil samples collected near a terpene plant grew in the presence of 1-menthene, with no other major source of carbon and energy. The organism was tentatively identified as a member of the genus Cladosporium. When this organism was grown in the presence of 1-menthene, with no other major source of carbon, substantial quantities of beta-isopropyl glutaric acid accumulated in the fermentation medium. beta-Isopropyl glutaric acid is probably an end product of the degradation of 1-menthene by the organism. PMID:16349992

Mukherjee, B B; Kraidman, G; Hill, I D

1974-06-01

189

Accumulation, transformation and tissue distribution of domoic acid, the amnesic shellfish poisoning toxin, in the common cuttlefish, Sepia officinalis  

Microsoft Academic Search

Domoic acid (DA) is a phycotoxin produced by some diatoms, mainly from the Pseudo-nitzschia genus, and has been detected throughout the marine food web. Although DA has been frequently found in cephalopod prey such as crustaceans and fish, little is known about DA accumulation in these molluscs. This study presents the first data showing relevant concentrations of DA detected in

Pedro R. Costa; Rui Rosa; Alexandra Duarte-Silva; Vanda Brotas; Maria Antónia M. Sampayo

2005-01-01

190

CHEMISTRY OF FOG WATER IN CALIFORNIA'S CENTRAL VALLEY: 2. PHOTOCHEMICAL TRANSFORMATIONS OF AMINO ACIDS AND ALKYL AMINES. (R825433)  

EPA Science Inventory

Although amino compounds are seemingly ubiquitous in atmospheric particles and deposition, little is known of their fate in the troposphere. We report here on the fate of 21 amino acids and alkyl amines in fog waters from Davis, California, illuminated with simulated sunlight ...

191

Nuclear factor of activated T-cells 1 increases sensitivity of v-myb transformed monoblasts to all-trans retinoic acid.  

PubMed

Nuclear factors of activated T-cells (NFATs) are important regulators of the cytokine gene expression in activated T-cells. In the last decade, NFATs have been shown to regulate cell cycle, differentiation and apoptosis in cells of various origins revealing their importance for cell homeostasis. In this study, we investigated the effects of NFAT1 on proliferation and differentiation of v-myb-transformed BM2 monoblasts. In contrast to many other leukemic cell lines, BM2 cells do not respond to retinoic acid. However, once overexpressing NFAT1, they became sensitive to all-trans retinoic acid (ATRA). The ATRA-treated BM2NFAT1 cells differentiated along monocyte/macrophage pathway as evidenced by changes in cell morphology, adherence, phagocytic and non-specific esterase activities, reactive oxygen species production, and vimentin expression. Furthermore, overexpressed NFAT1 either alone or in combination with the ATRA-driven signalling pathway deregulated cyclin A and retinoic acid receptor proteins in BM2 cells. Data presented in this study indicate that the NFAT1 and ATRA signalling pathways synergize in control of proliferation and differentiation of BM2 monoblasts. PMID:23571271

Tr?ka, Filip; Šmarda, Jan; Knopfová, Lucia; Kuziaková, Kate?ina; Beneš, Petr

2013-04-06

192

Reactivity and Selectivity of Charged Phenyl Radicals Toward Amino Acids in a Fourier-Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometer  

PubMed Central

The reactivity of ten charged phenyl radicals toward several amino acids was examined in the gas phase in a dual-cell Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. All radicals abstract a hydrogen atom from the amino acids, as expected. The most electrophilic radicals (with a greater calculated vertical electron affinity (EA) at the radical site) also react with these amino acids via NH2 abstraction (a nonradical nucleophilic addition-elimination reaction). Both the radical (hydrogen atom abstraction) and nonradical (NH2 abstraction) reaction efficiencies were found to increase with the electrophilicity (EA) of the radical. However, NH2 abstraction is more strongly influenced by EA. In contrast to an earlier report, the ionization energies of the amino acids do not appear to play a general reactivity controlling role. Studies using several partially deuterium-labeled amino acids revealed that abstraction of a hydrogen atom from the ?-carbon is only preferred for glycine; for the other amino acids, a hydrogen atom is preferentially abstracted from the side chain. The electrophilicity of the radicals does not appear to have a major influence on the site from which the hydrogen atom is abstracted. Hence, the regioselectivity of hydrogen atom abstraction appears to be independent of the structure of the radical but dependent on the structure of the amino acid. Surprisingly, abstraction of two hydrogen atoms was observed for the 3-nitro-5-dehydrophenyl pyridinium radical, indicating that substituents on the radical not only influence the EA of the radical but also can be involved in the reaction. In disagreement with an earlier report, proline was found to display several unprecedented reaction pathways that likely do not proceed via a radical mechanism but rather by a nucleophilic addition-elimination mechanism. Both NH2 and 15NH2 groups were abstracted from lysine labeled with 15N on the side-chain, indicating that NH2 abstraction occurs both from the amino terminus as well as from the side-chain. Quantum chemical calculations were employed to obtain insights into some of the reaction mechanisms.

Pates, George O.; Guler, Leonard; Nash, John J.; Kenttamaa, Hilkka I.

2011-01-01

193

Altered sensitivity of system A amino acid transport to ouabain in normal and transformed C3H-10T1/2 cells during the cell cycle  

SciTech Connect

Quiescent C3H-10T1/2 mouse fibroblasts that have not undergone any type of stress have a relatively low rate of 2-aminoisobutyrate (Aib) uptake by means of system A, which is primarily energized by the transmembrane Na{sup +} chemical gradient potential. System A activity in these cells is not sensitive to ouabain or proton ionophores. In contrast, methylcholanthrene-transformed and cofluent C3H-10T1/2 cells treated with ouabain utilize the membrane potential generated by the Na{sup +}, K{sup +}-ATPase pump to drive Aib transport by means of system A as shown by the sensitivity of transport activity to ouabain and proton ionophores. Since glucose is present during the assay, the proton ionophores do not affect the availability of ATP, as indicated by the undiminished uptake of {sup 86}Rb{sup +} by the Na{sup +}, K{sup +}-ATPase pump. As cells progress through the G{sub 1} phase of the cell cycle, they show an increased system A activity prior to entry into the S phase, which is also dependent on the electrogenicity of the Na{sup +}, K{sup +}-ATPase pump. There appears to be in all these cases a qualitative shift in the bioenergetic mechanism for the uptake of Aib as well as a marked quantitative increase in Aib uptake. The high activity after ouabain treatment was sustained in the transformed cells after removal of the ouabain, whereas in the confluent 10T1/2 cells the rate of uptake decayed rapidly, suggesting a difference in the mode of regulation. The authors conclude that transformed cells and normal cells in late G{sub 1} or under stress make use of the membrane potential generated by the Na{sup +}, K{sup +}-ATPase pump to drive amino acid uptake by means of system A.

Leister, K.J.; Schenerman, M.A.; Racker, E. (Cornell Univ., Ithaca, NY (USA))

1989-02-01

194

Nondestructive quantification of the soluble-solids content and the available acidity of apples by Fourier-transform near-infrared spectroscopy  

SciTech Connect

This research evaluated the feasibility of using Fourier-transform near-infrared (FT-NIR) spectroscopy to quantify the soluble-solids content (SSC) and the available acidity (VA) in intact apples. Partial least-squares calibration models, obtained from several preprocessing techniques (smoothing, derivative, etc.) in several wave-number ranges were compared. The best models were obtained with the high coefficient determination (r{sup 2}) 0.940 for the SSC and a moderate r{sup 2} of 0.801 for the VA, root-mean-square errors of prediction of 0.272% and 0.053%, and root-mean-square errors of calibration of 0.261% and 0.046%, respectively. The results indicate that the FT-NIR spectroscopy yields good predictions of the SSC and also showed the feasibility of using it to predict the VA of apples.

Ying Yibin; Liu Yande; Tao Yang

2005-09-01

195

The fatty acid oxidation product 15-A3t-Isoprostane is a potent inhibitor of NF?B transcription and macrophage transformation  

PubMed Central

Fatty acids such as eicosapentaenoic acid (EPA) have been shown to be beneficial for neurological function and human health. It is widely thought that oxidation products of EPA are responsible for biological activity, although the specific EPA peroxidation product(s) which exert these responses have not yet been identified. In this work we provide the first evidence that the synthesized representative cyclopentenone IsoP, 15-A3t-IsoP, serves as a potent inhibitor of lipopolysaccharide-stimulated macrophage activation. The anti-inflammatory activities of 15-A3t-IsoP were observed in response not only to lipopolysaccharide, but also to tumor necrosis factor alpha and IL-1b stimulation. Subsequently, this response blocked the ability of these compounds to stimulate nuclear factor kappa b (NF?B) activation and production of proinflammatory cytokines. The bioactivity of 15-A3t-IsoP was shown to be dependent upon an unsaturated carbonyl residue which transiently adducts to free thiols. Site directed mutagenesis of the redox sensitive C179 site of the Ikappa kinase beta subunit, blocked the biological activity of 15-A3t-IsoP and NF?B activation. The vasoprotective potential of 15-A3t-IsoP was underscored by the ability of this compound to block oxidized lipid accumulation, a critical step in foam cell transformation and atherosclerotic plaque formation. Taken together, these are the first data identifying the biological activity of a specific product of EPA peroxidation, which is formed in abundance in vivo. The clear mechanism linking 15-A3t-IsoP to redox control of NF?B transcription, and the compound's ability to block foam cell transformation suggest that 15-A3t-IsoP provides a unique and potent tool to provide vaso- and cytoprotection under conditions of oxidative stress.

Brooks, Joshua D.; Musiek, Erik S.; Koestner, Tyler R.; Stankowski, Jeannette N.; Howard, Jocelyn R.; Brunoldi, Enrico M.; Porta, Alessio; Zanoni, Giuseppe; Vidari, Giovanni; Morrow, Jason D.; Milne, Ginger L.; McLaughlin, BethAnn

2013-01-01

196

Inhibition of carcinoma and melanoma cell growth by type 1 transforming growth factor beta is dependent on the presence of polyunsaturated fatty acids.  

PubMed Central

Improved serum-free media were developed for the anchorage-dependent growth of A549 human lung carcinoma and B16 mouse melanoma cell lines in vitro. Type 1 transforming growth factor beta (TGF-beta 1) inhibited the growth of A549 or B16 cells under serum-free conditions or in the presence of 10% serum by 15-33%. In contrast, in the presence of micrograms/ml concentrations of polyunsaturated fatty acids (PUFAs), picomolar concentrations of TGF-beta 1 irreversibly inhibited the serum-free growth of A549 or B16 cells by 90-100%. The PUFAs alone had little effect on cell growth. Cell growth inhibition by TGF-beta 1 was not potentiated by saturated fatty acids, monounsaturated fatty acids, or prostaglandins. Inhibition of A549 or B16 cell growth by TGF-beta 1 in the presence of PUFAs was almost completely reversed by the antioxidant vitamin E, suggesting a role for lipid peroxidation in this process. Inhibition of A549 or B16 cell growth by TGF-beta 1 in the presence of 5% fetal calf serum was also potentiated by PUFAs and partially reversed by antioxidants. The presence of retinoic acid was required for maximal PUFA-dependent growth inhibition of A549 or B16 cells by TGF-beta 1 under some, but not all, conditions. These results suggest that inhibition of carcinoma and melanoma cell growth by TGF-beta 1 is mediated, in large part, by PUFAs. Images

Newman, M J

1990-01-01

197

Predicting homo-oligomers and hetero-oligomers by pseudo-amino acid composition: an approach from discrete wavelet transformation.  

PubMed

Many proteins exist in vivo as oligomers with different quaternary structural attributes rather than as individual chains. These proteins are the structural components of various biological functions, including cooperative effects, allosteric mechanisms and ion-channel gating. With the dramatic increase in the number of protein sequences submitted to the public databank, it is important for both basic research and drug discovery research to acquire the knowledge about possible quaternary structural attributes of their interested proteins in a timely manner. A high-throughput method (DWT_SVM), fusing discrete wavelet transform (DWT) and support vector machine (SVM) classifier algorithm with various physicochemical features, has been developed to predict protein quaternary structure. The accuracy in distinguishing candidate proteins as homo-oligomer or hetero-oligomer using the dataset R(2720) was 85.95% and 85.49% respectively by jackknife, showing that DWT_SVM is guide promising in predicting protein quaternary structures. The online service is available at http://bioinfo.ncu.edu.cn/Services.aspx . Protein sequences in FASTA format can be directly fed to the system OligoPred. The processed results will be presented in a diagram that includes the information of feature extraction and the classification error rate. PMID:21466835

Qiu, Jian-Ding; Sun, Xing-Yu; Suo, Sheng-Bao; Shi, Shao-Ping; Huang, Shu-Yun; Liang, Ru-Ping; Zhang, Li

2011-04-03

198

Unique relationship between interfacial tension test (IFT) and neutral number test (Acidity) of transformer insulation oil in PLN P3B JB - Jakarta and Banten Regional  

Microsoft Academic Search

Transformers are one of some important equipment on electricity network. Each utility, in this case PLN P3B Jawa-Bali, has to assure their reliability in order to maintain electrical power system stability by assessing transformer conditions. Insulation system, which consists of liquid and solid insulation, is the most important part of transformer system. The performance of transformer will depend on its

H. Gumilang

2009-01-01

199

A rapid method for the quantification of fatty acids in fats and oils with emphasis on trans fatty acids using Fourier Transform near infrared spectroscopy (FT-NIR).  

PubMed

A rapid method was developed for classifying and quantifying the FA composition of edible oils and fats using Fourier Transform near infrared spectroscopy (FT-NIR). The FT-NIR spectra showed unique fingerprints for saturated FA, cis and trans monounsaturated FA, and all n-6 and n-3 PUFA within TAG to permit qualitative and quantitative comparisons of fats and oils. The quantitative models were based on incorporating accurate GC data of the different fats and oils and FT-NIR spectral information into the calibration model using chemometric analysis. FT-NIR classification models were developed based on chemometric analyses of 55 fats, oils, and fat/oil mixtures that were used in the identification of similar materials. This database was used to prepare three calibration models-one suitable for the analysis of common fats and oils with low levels of trans FA, and the other two for fats and oils with intermediate and high levels of trans FA. The FT-NIR method showed great potential to provide the complete FA composition of unknown fats and oils in minutes. Compared with the official GC method, the FT-NIR method analyzed fats and oils directly in their neat form and required no derivatization of the fats to volatile FAME, followed by time-consuming GC separations and analyses. The FT-NIR method also compared well with the official FTIR method using an attenuated total reflectance (ATR) cell; the latter provided only quantification of specific functional groups, such as the total trans FA content, whereas FT-NIR provided the complete FA profile. The FT-NIR method has the potential to be used for rapid screening and/or monitoring of fat products, trans FA determinations for regulatory labeling purposes, and detection of contaminants. The quantitative FT-NIR results for various edible oils and fats and their mixtures are presented based on the FT-NIR models developed. PMID:16296405

Azizian, Hormoz; Kramer, John K G

2005-08-01

200

Accumulation, transformation and tissue distribution of domoic acid, the amnesic shellfish poisoning toxin, in the common cuttlefish, Sepia officinalis.  

PubMed

Domoic acid (DA) is a phycotoxin produced by some diatoms, mainly from the Pseudo-nitzschia genus, and has been detected throughout the marine food web. Although DA has been frequently found in cephalopod prey such as crustaceans and fish, little is known about DA accumulation in these molluscs. This study presents the first data showing relevant concentrations of DA detected in the common cuttlefish, Sepia officinalis, which is one of the most studied cephalopod species in the world. Domoic acid was consistently found throughout 2003 and 2004 in the digestive gland of cuttlefish reaching concentrations of 241.7 microg DA g(-1). The highest DA values were detected during spring and summer months, periods when Pseudo-nitzschia occur in the plankton. In fact, Pseudo-nitzschia blooms preceded the highest DA concentrations in cuttlefish. Evaluation of DA tissue distribution showed elevated DA concentrations in the digestive gland and branchial hearts. Further, DA isomers comprised a relevant percentage of the toxin profile, indicating degradation and biotransformation of the toxin in the branchial hearts. The common cuttlefish, like other cephalopod species, plays a central position in the food web and might be a new DA vector to top predators like marine mammals. Human intoxications are not expected since DA was only seldom detected in the mantle and even then in very low levels (max 0.7 microg DA g(-1)). However, in some countries whole juvenile animals are consumed (i.e. without evisceration) and in this case they might represent a risk to human health. This study contributes to understanding the occurrence of phycotoxins in cephalopods and reveals a new member of the marine food web able to accumulate DA. PMID:15961171

Costa, Pedro R; Rosa, Rui; Duarte-Silva, Alexandra; Brotas, Vanda; Sampayo, Maria Antónia M

2005-08-15

201

Transforming growth factor-beta 1 in adipose derived stem cells conditioned medium is a dominant paracrine mediator determines hyaluronic acid and collagen expression profile  

PubMed Central

Conditioned medium from adipose derived stem cells (ADSC-CM) stimulates both collagen synthesis and migration of fibroblasts, and accelerates wound healing in vivo. Recently, the production and secretion of growth factors has been identified as an essential function of adipose-derived stem cells (ADSCs). However, the main soluble factor of ADSC-CM which mediates paracrine effects and its underlying mechanism has not been elucidated yet. In this study, we considered transforming growth factor-beta1 (TGF-?1) as a strong candidate for paracrine effect of ADSC-CM and investigated collagen synthesis and hyaluronic acid synthase (HAS) expression. After ADSC-CM addition, collagen type I, type III, HAS and hyaluronic acid (HA) expressions on human dermal fibroblasts (HDFs) were evaluated. Furthermore, to clarify effects of TGF-?1 as a paracrine mediator, TGF-?1 antibody and external supplementary TGF-?1 were treated to HDFs. Collagens type I, type III, HAS-1 and HAS-2 mRNA expressions of HDFs were greatly increased by ADSC-CM treatment, however there was no change in TGF-?1 antibody treated HDFs compared with non-treated control. These results strongly demonstrate that TGF-?1 plays an important role as a paracrine mediator of ECM synthesis. The fact that TGF-?1 contained in ADSC-CM not only accelerates collagen deposition but also increase hyaluronic acid synthesis of HDFs through HAS-1 and HAS-2 expression was also elucidated in this study. Therefore, ADSC-CM shows promise for the treatment of cutaneous wounds and accelerates granulation formation during healing process.

Jung, Hana; Kim, Hak Hee; Lee, Dong Hee; Hwang, Yu-Shik; Yang, Hyeong-Cheol

2011-01-01

202

Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s as high-efficiency catalysts for carbonyl-group transformation reactions.  

PubMed

Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s [M(Cp)(2)][OSO(2)C(8)F(17)](2)?nH(2)O?THF (M = Zr (2?a?3?H(2)O?THF), M = Ti (2?b?2?H(2)O?THF)) were synthesized by the reaction of [M(Cp)(2)]Cl(2) (M = Zr (1?a), M = Ti (1?b)) with nBuLi and C(8)F(17)SO(3)H (2?equiv) or with C(8)F(17)SO(3)Ag (2?equiv). The hydrate numbers (n) of these complexes were variable, changing from 0 to 4 depending on conditions. In contrast to well-known metallocene triflates, these complexes suffered no change in open air for a year. thermogravimetry-differential scanning calorimetry (TG-DSC) analysis showed that 2?a and 2?b were thermally stable at 300 and 180?°C, respectively. These complexes exhibited unusually high solubility in polar organic solvents. Conductivity measurement showed that the complexes (2?a and 2?b) were ionic dissociation in CH(3)CN solution. X-ray analysis result confirmed 2?a?3?H(2)O?THF was a cationic organometallic Lewis acid. UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2?a. Fluorescence spectra showed that the Lewis acidity of 2?a fell between those of Sc(3+) (?(em)=474?nm) and Fe(3+) (?(em)=478?nm). ESR spectra showed the Lewis acidity of 2?a (0.91?eV) was at the same level as that of Sc(3+) (1.00?eV) and Y(3+) (0.85?eV), while the Lewis acidity of 2?b (1.06?eV) was larger than that of Sc(3+) (1.00?eV) and Y(3+) (0.85?eV). They showed high catalytic ability in carbonyl-compound transformation reactions, such as the Mannich reaction, the Mukaiyama aldol reaction, allylation of aldehydes, the Friedel-Crafts acylation of alkyl aromatic ethers, and cyclotrimerization of ketones. Moreover, the complexes possessed good reusability. On account of their excellent catalytic efficiency, stability, and reusability, the complexes will find broad catalytic applications in organic synthesis. PMID:22504964

Qiu, Renhua; Xu, Xinhua; Peng, Lifeng; Zhao, Yalei; Li, Ningbo; Yin, Shuangfeng

2012-04-13

203

Collection of VLE data for acid gas---alkanolamine systems using fourier transform infrared spectroscopy. [Vapor-liquid equilibrium  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor--liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as hindered'' amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor--liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 [times] 10[sup 14] BTU/yr.

Bullin, J.A.; Frazier, R.E.

1992-01-01

204

Copper redox transformation and complexation by reduced and oxidized soil humic Acid. 2. Potentiometric titrations and dialysis cell experiments.  

PubMed

Cation binding and electron transfer reactions of humic substances determine copper speciation in redox-dynamic systems, but quantitative studies for Cu(+) binding to humic substances are lacking. We investigated reduction of Cu(2+) and binding of Cu(+) at pH 7.0 in a dialysis cell experiment using reduced and reoxidized soil humic acid (HA) as reductant and sorbent at copper loadings of 9.5-600 mmol kg(-1). The data were used to quantitatively explain the interaction between cation binding and electron transfer processes that determine copper speciation in the presence of HA under anoxic and oxic conditions. Addition of Cu(2+) to reduced HA resulted in almost complete reduction to Cu(I) within 1 h. Reduction was also significant under oxic conditions. The slow decrease of the Cu(I) fraction was attributed to formation of Cu(0) based on thermodynamic consideration. Cu(+) binding to HA was found to be strong compared to other chalcophile cations like Ag(+) or Cd(2+). Our results indicate that Cu(+) and Cu(2+) isotherms exhibit a redox potential-dependent intersection point. According to the differences in Cu(+) and Cu(2+) binding, the presence of HA was found to extend the stability field of Cu(II) to moderately reducing conditions and to reduce the stability field of Cu(0) due to the formation of Cu(I) complexes. PMID:24050604

Maurer, Felix; Christl, Iso; Fulda, Beate; Voegelin, Andreas; Kretzschmar, Ruben

2013-09-19

205

Glycyrrhizic acid alters Kaposi sarcoma-associated herpesvirus latency, triggering p53-mediated apoptosis in transformed B lymphocytes  

PubMed Central

Kaposi sarcoma–associated herpesvirus (KSHV) is linked with all clinical forms of Kaposi sarcoma and several lymphoproliferative disorders. Like other herpesviruses, KSHV becomes latent in the infected cells, expressing only a few genes that are essential for the establishment and maintenance of its latency and for the survival of the infected cells. Inhibiting the expression of these latent genes should lead to eradication of herpesvirus infection. All currently available drugs are ineffective against latent infection. Here we show, for the first time to our knowledge, that latent infection with KSHV in B lymphocytes can be terminated by glycyrrhizic acid (GA), a triterpenoid compound earlier shown to inhibit the lytic replication of other herpesviruses. We demonstrate that GA disrupts latent KSHV infection by downregulating the expression of latency-associated nuclear antigen (LANA) and upregulating the expression of viral cyclin and selectively induces cell death of KSHV-infected cells. We show that reduced levels of LANA lead to p53 reactivation, an increase in ROS, and mitochondrial dysfunction, which result in G1 cell cycle arrest, DNA fragmentation, and oxidative stress–mediated apoptosis. Latent genes are involved in KSHV-induced oncogenesis, and strategies to interfere with their expression might prove useful for eradicating latent KSHV infection and have future therapeutic implications.

Curreli, Francesca; Friedman-Kien, Alvin E.; Flore, Ornella

2005-01-01

206

Regulations of collagen synthesis by ascorbic acid, transforming growth factor-? and interferon-? in human dermal fibroblasts cultured in three-dimensional collagen gel are photoaging and aging-independent  

Microsoft Academic Search

Decreased collagen synthesis and loss of responsiveness to growth factors are well known phenomena in in vivo or in vitro aged cells. Ascorbic acid and some cytokines such as transforming growth factor-? and interferon-? are important regulators of collagen synthesis. To investigate the responsiveness of fibroblasts with regard to the photoaging and aging process, we examined the effect of ascorbic

Jin Ho Chung; Sang Ho Youn; Oh Sang Kwon; Kwang Hyun Cho; Jai Il Youn; Hee Chul Eun

1997-01-01

207

Investigation of isomeric transformations of chlorogenic acid in buffers and biological matrixes by ultraperformance liquid chromatography coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight mass spectrometry.  

PubMed

Ultraperformance liquid chromatography coupled with hybrid quadrupole/ion mobility/orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (UPLC-IM-MS) was used to study the isomeric transformations of trans-5-caffeoylquinic acid, an extremely active compound present in multiple vegetables, fruits, and beverages. The UPLC/oa-TOF MS results proved that in phosphate buffer (pH 7.4), plasma, or urine sample, trans-5-caffeoylquinic acid first isomerizes to trans-4-caffeoylquinic acid and then to trans-3-caffeoylquinic acid by intramolecular acyl migration. When exposed to UV light, trans-3-, -4-, and -5-caffeoylquinic acids undergo cis/trans isomerization to form cis isomers. The isomerization was solely dependent on the pH of the matrix, as well as the incubation temperature, and was independent of metabolic enzymes. UPLC-IM-MS results revealed that a reversible cis/trans isomerization of caffeoylquinic acids could also be induced by the electric field in an electrospray source. Thus, understanding the possible role of electric field-induced isomerization of caffeoylquinic acids may help lessen the confusion between gas phase phenomena and liquid state chemistry when applying IM-MS analysis. The comprehensive understanding of caffeoylquinic acid isomerization transformations is crucial for the appropriate handling of samples and interpretation of experimental data. PMID:21942218

Xie, Cen; Yu, Kate; Zhong, Dafang; Yuan, Tao; Ye, Fei; Jarrell, Joseph Andy; Millar, Alan; Chen, Xiaoyan

2011-10-03

208

Sources, transformation and fate of particulate amino acids and hexosamines under varying hydrological regimes in the tropical Wenchang/Wenjiao Rivers and Estuary, Hainan, China  

NASA Astrophysics Data System (ADS)

The small tropical Wenchang and Wenjiao Rivers on the island of Hainan, tropical China, are affected by effluents from municipal sewage, aquaculture and agriculture, and by contrasting hydrological regimes related to monsoon and tropical storms. In order to obtain information on the sources, transformation and fate of organic matter (OM) we investigated the amount and composition of amino acids and hexosamines as well as the carbon isotope composition in suspended particulate matter (SPM) from the Wenchang/Wenjiao Estuary. SPM was collected along the salinity gradient starting from the river sites, along the lagoon-shaped Bamen Bay to coastal waters during four sampling campaigns between 2006 and 2009. SPM concentrations ranged between 4.7 and 58.2mgL-1. Apart from highest values after heavy rain events in spring and summer, SPM showed little seasonal variation, but increased with salinity. From SPM POC% (1.2-20.9%), C/N (4.9-16.5) and ?13Corg (-31.5 to -19.5‰), the molar composition and content of amino acids and hexosamines (8.2-156.2mgg-1 dry weight) and by comparison with sediments, mangroves, soils and plants we are able to show that soil-derived material, freshwater and marine plankton were the major sources of suspended OM. High POC and amino acid contents were related to primary production sustained by dissolved nutrients to a large extent stemming from municipal and aquaculture effluents. Factor analysis showed that the suite of biogeochemical parameters measured clearly depict the terrestrial vs. marine origin and the freshness/reactivity of OM. The four groups of samples resulting from cluster analysis were basically related to varying hydrological regimes. With respect to the sources, degradation and fate of particulate OM the major factors were: (i) the year round input of labile, amino acid rich riverine OM matter at the freshwater dominated sites, (ii) high input of degraded soil OM after heavy rains with dispersal throughout the estuary and export to the adjacent coastal area, (iii) significant production of labile marine OM especially during summer inside the bay and the (iv) dominance of refractory marine OM during winter and spring season and in the offshore region. While a major part of the fresh OM fuelled by anthropogenic nutrients appears to be stored or recycled inside the bay, periodic torrential rainfalls can lead to a pulsed export of this OM to the coastal area where it may adversely affect seagrass meadows and coral reefs.

Unger, Daniela; Herbeck, Lucia S.; Li, Min; Bao, Hongyan; Wu, Ying; Zhang, Jing; Jennerjahn, Tim

2013-04-01

209

Anteroposterior gradient of epithelial transformation during amphibian intestinal remodeling: immunohistochemical detection of intestinal fatty acid-binding protein.  

PubMed

To determine whether the remodeling of the well-organized intestinal epithelium during amphibian metamorphosis is regionally regulated along the anteroposterior axis of the intestine, we raised a polyclonal antibody against the Xenopus laevis intestinal fatty acid-binding protein (IFABP), which is known to be specifically expressed in intestinal absorptive cells, and examined immunohistochemically the differentiation, proliferation, and apoptosis of the epithelial cells throughout X. laevis small intestine. During pre- and prometamorphosis, IFABP-immunoreactive (ir) epithelial cells were localized only in the anterior half of the larval intestine. At the beginning of metamorphic climax, apoptotic cells detected by nick end-labeling (TUNEL) suddenly increased in number in the entire larval epithelium, concurrently with the appearance of adult epithelial primordia. Subsequently, the adult primordia in the anterior part of the intestine developed more rapidly by active cell proliferation than those in the posterior part, and replaced the larval epithelial cells earlier than those in the posterior part. IFABP-ir cells in the adult epithelium were first detectable at the tips of newly formed folds in the proximal part of the intestine. Thereafter, IFABP expression gradually progressed both in the anteroposterior direction and in the crest-trough direction of the folds. These results suggest that developmental processes of the adult epithelium in the X. laevis intestine are regionally regulated along the anteroposterior axis of the intestine, which is maintained throughout metamorphosis, and along the trough-crest axis of the epithelial folds, which is newly established during metamorphosis. Furthermore, the regional differences in IFABP expression along the anteroposterior axis of the intestine were reproduced in organ cultures in vitro. In addition, IFABP expression was first down-regulated and then reactivated in vitro when the anterior part, but not the posterior part, of the larval intestine was treated with thyroid hormone (TH) for extended periods. Therefore, it seems that, in addition to TH, an endogenous factor(s) localized in the intestine itself with an anteroposterior gradient participates in the development of the adult epithelium during amphibian metamorphosis. PMID:9405104

Ishizuya-Oka, A; Ueda, S; Damjanovski, S; Li, Q; Liang, V C; Shi, Y B

1997-12-01

210

Solid State Chemistry of Organic Polyvalent Iodine Compounds. IV. Topotactic Transformations of 2-Iodo-3'-Chlorodibenzoyl Peroxide and the Crystal Structure of m-Chlorobenzoic Acid.  

National Technical Information Service (NTIS)

Single crystals of 2-iodo-3'-chlorodibenzoyl peroxide (P) undergo several competitive and consecutive topotactic transformations: upon standing in the laboratory atmosphere or during X-ray photography at approx. 22 C, crystalline P is transformed to pseud...

J. Z. Gougoutas L. Lessinger

1973-01-01

211

Transforming acidic coiled-coil protein-3 (Tacc3) acts as a negative regulator of Notch signaling through binding to CDC10 /Ankyrin repeats  

PubMed Central

We have identified the transforming acidic coiled-coil protein-3 (Tacc3) as a binding partner for Notch4/Int3 and were able to show that it binds to the intracellular domain (ICD) of all members of the Notch receptor family. Members of the Tacc family reside at the centrosomes and associates with microtubules. Recent studies suggest that Tacc3 also contributes to the regulation of gene transcription. Tacc3 specifically interacts with the Notch4/Int3 CDC10/Ankyrin repeats and to a lesser extent, with residues C-terminal to these repeats in the ICD. Dual label immunofluorescence of mouse mammary tissue shows Tacc3 co-localizes with the Notch3 ICD. Co-immunoprecipitation of endogenous Notch and Tacc3 proteins from NIH 3T3 cell extracts, lung and mammary gland confirms that these two proteins interact under physiological conditions. In addition, knock down of Tacc3 in NIH 3T3 cells leads to the up-regulation of Hey2, a target gene for Notch signaling. The affinity of Tacc3 binding to Notch4/Int3 ICD is similar to that between Rbpj and Notch4/Int3 ICD. Notch4/Int3 ICD-Tacc3 interaction results in the inhibition of transcription from a Hes1-Luciferase reporter vector in COS-1 cells. The inhibition was reversed in these cells by increasing the levels of Rbpj. Taken together, these results suggest that Tacc3 is a negative regulator of the Notch signaling pathway.

Bargo, Sharon; Raafat, Ahmed; McCurdy, David; Amirjazil, Idean; Shu, Youmin; Traicoff, June; Plant, Joshua; Vonderhaar, Barbara K.; Callahan, Robert

2010-01-01

212

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

213

Occurrence and fate of the angiotensin II receptor antagonist transformation product valsartan acid in the water cycle - A comparative study with selected ?-blockers and the persistent anthropogenic wastewater indicators carbamazepine and acesulfame.  

PubMed

The substantial transformation of the angiotensin II receptor antagonist valsartan to the transformation product 2'-(2H-tetrazol-5-yl)-[1,1'-biphenyl]-4-carboxylic acid (referred to as valsartan acid) during the activated sludge process was demonstrated in the literature and confirmed in the here presented study. However, there was a severe lack of knowledge regarding the occurrence and fate of this compound in surface water and its behavior during drinking water treatment. In this work a comparative study on the occurrence and persistency of valsartan acid, three frequently used ?-blockers (metoprolol, atenolol, and sotalol), atenolol acid (one significant transformation product of atenolol and metoprolol), and the two widely distributed persistent anthropogenic wastewater indicators carbamazepine and acesulfame in raw sewage, treated wastewater, surface water, groundwater, and tap water is presented. Median concentrations of valsartan acid in the analyzed matrices were 101, 1,310, 69, <1.0, and 65 ng L(-1), respectively. Treated effluents from wastewater treatment plants were confirmed as significant source. Regarding concentration levels of pharmaceutical residues in surface waters valsartan acid was found just as relevant as the analyzed ?-blockers and the anticonvulsant carbamazepine. Regarding its persistency in surface waters it was comparable to carbamazepine and acesulfame. Furthermore, removal of valsartan acid during bank filtration was poor, which demonstrated the relevance of this compound for drinking water suppliers. Regarding drinking water treatment (Muelheim Process) the compound was resistant to ozonation but effectively eliminated (?90%) by subsequent activated carbon filtration. However, without applying activated carbon filtration the compound may enter the drinking water distribution system as it was demonstrated for Berlin tap water. PMID:24070867

Nödler, Karsten; Hillebrand, Olav; Idzik, Krzysztof; Strathmann, Martin; Schiperski, Ferry; Zirlewagen, Johannes; Licha, Tobias

2013-09-10

214

Secreted protein acidic and rich in cysteine (SPARC) is upregulated by transforming growth factor (TGF)-? and is required for TGF-?-induced hydrogen peroxide production in fibroblasts  

PubMed Central

Background Idiopathic pulmonary fibrosis (IPF) is a poorly understood progressive disease characterized by the recurrent damage of alveolar epithelial cells as well as inappropriate expansion and activation of fibroblasts resulting in pronounced extracellular matrix (ECM) deposition. Although recent studies have indicated the involvement of secreted protein acidic and rich in cysteine (SPARC), a matricellular protein regulating ECM deposition, in the pathogenesis of fibrosis, factors regulating SPARC expression or roles of SPARC in fibrosis have not been fully elucidated. Results Among the profibrotic factors examined in cultured fibroblasts, we showed that SPARC expression was upregulated mainly by transforming growth factor (TGF)-?. We also showed that expression of SPARC in the lung was upregulated in the murine bleomycin-induced pulmonary fibrosis model, which was inhibited by TGF-? receptor I inhibitor. Knockdown of SPARC in fibroblasts using siRNA or treatment with the antioxidant N-acetylcysteine attenuated epithelial cell injury induced by TGF-?-activated fibroblasts in a coculture system. We also demonstrated that SPARC was required for hydrogen peroxide (H2O2) production in fibroblasts treated with TGF-?. Furthermore, TGF-? activated integrin-linked kinase (ILK), which was inhibited by SPARC siRNA. Knockdown of ILK attenuated extracellular H2O2 generation in TGF-?-stimulated fibroblasts. Our results indicated that SPARC is upregulated by TGF-? and is required for TGF-?-induced H2O2 production via activation of ILK, and this H2O2 production from fibroblasts is capable of causing epithelial cell injury. Conclusions The results presented in this study suggest that SPARC plays a role in epithelial damage in the IPF lung via enhanced H2O2 production from fibroblasts activated by TGF-?. Therefore, SPARC inhibition may prevent epithelial injury in IPF lung and represent a potential therapeutic approach for IPF.

2013-01-01

215

Transforming acidic coiled-coil 3 and Aurora-A interact in human thyrocytes and their expression is deregulated in thyroid cancer tissues  

PubMed Central

Aurora-A kinase has recently been shown to be deregulated in thyroid cancer cells and tissues. Among the Aurora-A substrates identified, transforming acidic coiled-coil (TACC3), a member of the TACC family, plays an important role in cell cycle progression and alterations of its expression occur in different cancer tissues. In this study, we demonstrated the expression of the TACC3 gene in normal human thyroid cells (HTU5), and its modulation at both mRNA and protein levels during cell cycle. Its expression was found, with respect to HTU5 cells, unchanged in cells derived from a benign thyroid follicular tumor (HTU42), and significantly reduced in cell lines derived from follicular (FTC-133), papillary (B-CPAP), and anaplastic thyroid carcinomas (CAL-62 and 8305C). Moreover, in 16 differentiated thyroid cancer tissues, TACC3 mRNA levels were found, with respect to normal matched tissues, reduced by twofold in 56% of cases and increased by twofold in 44% of cases. In the same tissues, a correlation between the expression of the TACC3 and Aurora-A mRNAs was observed. TACC3 and Aurora-A interact in vivo in thyroid cells and both proteins localized onto the mitotic structure of thyroid cells. Finally, TACC3 localization on spindle microtubule was no more observed following the inhibition of Aurora kinase activity by VX-680. We propose that Aurora-A and TACC3 interaction is important to control the mitotic spindle organization required for proper chromosome segregation.

Ulisse, Salvatore; Baldini, Enke; Toller, Matteo; Delcros, Jean-Guy; Gueho, Aurelie; Curcio, Francesco; De Antoni, Enrico; Giacomelli, Laura; Ambesi-Impiombato, Francesco S; Bocchini, Sarah; D'Armiento, Massimino; Arlot-Bonnemains, Yannick

2007-01-01

216

The Third Member of the Transforming Acidic Coiled Coil-Containing Gene Family, TACC3, Maps in 4p16, Close to Translocation Breakpoints in Multiple Myeloma, and Is Upregulated in Various Cancer Cell Lines  

Microsoft Academic Search

We have recently identified a novel gene, TACC1 (transforming acidic coiled coil-containing gene 1), which is located close to FGFR1 within a region amplified in breast cancer on human chromosome 8p11. The coiled coil domain of this gene identified a series of cDNAs in the expressed sequence tag database, which suggested the existence of a family of TACC genes comprising

Ivan H Still; Pauline Vince; John K Cowell

1999-01-01

217

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

218

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

219

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

220

Accurate Fourier Transform Infrared (FT-IR) Spectroscopy Measurements of Nitrogen Dioxide (NO2) and Nitric Acid (HNO3) Calibrated with Synthetic Spectra.  

PubMed

A novel method for determining the accuracy of laboratory-based measurements of nitrogen dioxide (NO2) and nitric acid (HNO3) mole fractions using Fourier transform infrared (FT-IR) spectroscopy 1 cm(-1) resolution instruments calibrated with synthetic spectra has been developed. The traceability of these measurement results is to the reference line strength data contained within the high-resolution transmission molecular absorption (HITRAN) database. Incorporating a proper estimate of the uncertainty of this data into the measurement results will ensure that the SI traceable values are encompassed within the uncertainty of the measurement results. The major contributors to the uncertainties of the results are, in descending order of importance, the uncertainty in the line strength values (HITRAN 2004), the uncertainty attributed to the generation of reference spectra (including knowledge of the optical path length of the FT-IR gas cell), and temperature measurements of the gas. The stability of the FT-IR instrument itself is only a minor contributor to the overall uncertainty of the measurements. FT-IR measurements of NO2 mole fractions at nominal values of 10 ?mol mol(-1) calibrated with synthetic spectra lead to standard uncertainties of 0.34 ?mol mol(-1) (3.4% relative). In contrast, calibration of the FT-IR instrument with SI traceable gas standards generated by a dynamic weighing system resulted in measurements results with standard uncertainties of 0.04 ?mol mol(-1) (0.4% relative). When comparing the consistency of measurement results based on the synthetic calibration method against those obtained by calibrations with SI traceable gas standards, the existence of a potential bias of ?5% was observed, although this was within the stated uncertainties of the results. The FT-IR measurements of HNO3 mole fractions at nominal values of 200 nmol mol(-1) calibrated with synthetic spectra resulted in values with standard uncertainties of 23 nmol mol(-1) (11% relative) with the dominating uncertainty in this case arising from the stabilization of the mole fraction value within the FT-IR gas cell. PMID:24067574

Flores, Edgar; Viallon, Joële; Moussay, Philippe; Wielgosz, Robert Ian

2013-10-01

221

Effect of salicylic acid, methyl jasmonate, ethephon and cantharidin on anthraquinone production by Rubia cordifolia callus cultures transformed with the rolB and rolC genes  

Microsoft Academic Search

It has been suggested that the rol genes of Agrobacterium rhizogenes could play an essential role in the activation of secondary metabolite production in plant transformed cultures. This study investigated whether the content of anthraquinone phytoalexins was changed in callus cultures of Rubia cordifolia transgenic for the 35S-rolB and 35S-rolC genes in comparison with a non-transformed callus culture. The anthraquinone

V. P. Bulgakov; G. K. Tchernoded; N. P. Mischenko; M. V. Khodakovskaya; V. P. Glazunov; S. V. Radchenko; E. V. Zvereva; S. A. Fedoreyev; Yu. N Zhuravlev

2002-01-01

222

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

223

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

224

[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

225

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

226

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

227

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

228

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

229

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

230

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

231

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

232

Systematic Analysis of the Amino Acid Residues of Human Papillomavirus Type 16 E7 Conserved Region 3 Involved in Dimerization and Transformation ?  

PubMed Central

The human papillomavirus (HPV) E7 oncoprotein exists as a dimer and acts by binding to many cellular factors, preventing or retargeting their function and thereby making the infected cell conducive for viral replication. Dimerization of E7 is attributed primarily to the C-terminal domain, referred to as conserved region 3 (CR3). CR3 is highly structured and is necessary for E7's transformation ability. It is also required for binding of numerous E7 cellular targets. To systematically analyze the molecular mechanisms by which HPV16 E7 CR3 contributes to carcinogenesis, we created a comprehensive panel of mutations in residues predicted to be exposed on the surface of CR3. We analyzed our novel collection of mutants, as well as mutants targeting predicted hydrophobic core residues of the dimer, for the ability to dimerize. The same set of mutants was also assessed functionally for transformation capability in a baby rat kidney cell assay in conjugation with activated ras. We show that some mutants of HPV16 E7 CR3 failed to dimerize yet were still able to transform baby rat kidney cells. Our results identify several novel E7 mutants that abrogate transformation and also indicate that E7 does not need to exist as a stable dimer in order to transform cells.

Todorovic, Biljana; Massimi, Paola; Hung, Katherine; Shaw, Gary S.; Banks, Lawrence; Mymryk, Joe S.

2011-01-01

233

Agrobacterium -mediated Transformation of Brassica juncea with a Cyanobacterial ( Synechocystis PCC6803) Delta6 Desaturase Gene Leads to Production of Gamma-linolenic Acid  

Microsoft Academic Search

Genetic manipulation of the oil-yielding crop plants for better oil quality through biotechnological methods is an important aspect of crop improvement. Due to the inherent absence of the ?6-desaturase (d6D) function, Brassica juncea, an oil-yielding crop plant, is unable to synthesize ?-linolenic acid (GLA), a nutritionally important fatty acid although the crop plant synthesizes the precursor fatty acids required for

Biswajit Das; Lily Goswami; Sudipta Ray; Shilpi Ghosh; Sanghamitra Bhattacharyya; Sampa Das; Arun Lahiri Majumder

2006-01-01

234

The influence of different land management practices on the transformation of humic acids in heavy loamy soddy-podzolic soils of the Cis-Urals region  

NASA Astrophysics Data System (ADS)

The elemental composition and structure of humic acids were studied in heavy loamy soddy-podzolic soils of the Cis-Urals region under different land management practices. The humic acids in the soil of the long-term clean fallow, overgrown fallow (abandoned plot), and crop rotation plots differed in their composition and properties. The humic acids in the soils of the crop rotation with the regular application of manure and of the overgrown fallow were enriched in the components of both their central (nuclear) and peripheral parts. Such a structure ensured the active participation of humic acids in the carbon cycle with the simultaneous preservation of the soil's fertility.

Zavyalova, N. E.; Konchits, V. A.

2011-01-01

235

Relationships of a Transforming Growth Factor-?2 Single Nucleotide Polymorphism and Messenger Ribonucleic Acid Abundance with Bone and Production Traits in Chickens  

Microsoft Academic Search

Osteoporosis is a serious problem for the laying hen industry with economic, production, and wel- fare consequences. Transforming growth factor-?2 (TGF?2) has been implicated as an important factor in coupling bone resorption and formation in bone remodel- ing. The current study was designed to determine if TGF?2 was associated with variation in bone mineraliza- tion in chickens, using 2 complementary

A. K. Bennett; P. Y. Hester; D. M. Spurlock

236

Alteration of a single amino acid in the basic domain of Marek's disease virus Meq oncoprotein plays an important role in T-cell transformation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease virus encoded oncoprotein, Meq, has been shown to play a major role in transformation of T-lymphocytes. We have earlier shown that replacement of the meq gene in the very virulent strain Md5 with that of vaccine strain CVI988/Rispens resulted in virus attenuation in chickens. To dete...

237

Petroleomics: Applications in the Fingerprinting of the Acidic and Basic Crude Oil Components Detected by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

Microsoft Academic Search

We have previously demonstrated the ability of electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to resolve and identify the polar species found in all petroleum distillates. The ultrahigh resolving power and mass accuracy of FT-ICR MS allows for the identification of thousands of compounds in crude oils without prior chromatographic separation. In Chapter 3, we

Geoffrey Christoffersen Klein

2005-01-01

238

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

239

Retinoic Acid Resistance at Late Stages of Human Papillomavirus Type 16-Mediated Transformation of Human Keratinocytes Arises Despite Intact Retinoid Signaling and Is Due to a Loss of Sensitivity to Transforming Growth Factor-?  

Microsoft Academic Search

In our in vitro model of human cell carcinogenesis, normal human foreskin keratinocytes (HKc) transfected with human papillomavirus type 16 DNA (HKc\\/HPV16) progress toward malignancy through several phenotypically defined and reproducible “steps” that include immortalization, growth factor independence (HKc\\/GFI), differentiation resistance (HKc\\/DR), and ultimately malignant conversion. While HKc\\/HPV16 are very sensitive to growth inhibition by all-trans-retinoic acid (RA) at early

Darrell R. Borger; Yi-de Mi; Gemma Geslani; Li Li Zyzak; Ayse Batova; Timur S. W. Engin; Lucia Pirisi; Kim E. Creek

2000-01-01

240

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

241

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

242

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

243

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.

244

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.

245

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

246

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

247

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

248

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

249

Tumor Necrosis Factor, Ceramide, Transforming Growth Factor 1, and Aging Reduce Na+\\/I- Symporter Messenger Ribonucleic Acid Levels in FRTL-5 Cells  

Microsoft Academic Search

Iodide uptake, which is necessary for thyroid hormone synthesis, can be inhibited by aging, withdrawal of TSH, or increased tumor necrosis factor (TNF) and transforming growth factor (TGF)-b1 levels resulting from the nonthyroid illness syndrome. TNF induces recep- tor-mediated activation of sphingomyelinase, which converts sphin- gomyelin to ceramide, a mediator of TNF actions. Thyroid follicular cells transport iodide from blood

A. EUGENE PEKARY; JEROME M. HERSHMAN; LORETTA BERG

1998-01-01

250

Emissions of formaldehyde, acetic acid, methanol, and other trace gases from biomass fires in North Carolina measured by airborne Fourier transform infrared spectroscopy  

Microsoft Academic Search

Biomass burning is an important source of many trace gases in the global troposphere. We have constructed an airborne trace gas measurement system consisting of a Fourier transform infrared spectrometer (FTIR) coupled to a ``flow-through'' multipass cell (AFTIR) and installed it on a U.S. Department of Agriculture Forest Service King Air B-90. The first measurements with the new system were

R. J. Yokelson; J. G. Goode; D. E. Ward; R. A. Susott; R. E. Babbitt; D. D. Wade; I. Bertschi; D. W. T. Griffith; W. M. Hao

1999-01-01

251

Enzymatic transformation of 2-O-?- d-glucopyranosyl- l-ascorbic acid (AA2G) by immobilized ?-cyclodextrin glucanotransferase from recombinant Escherichia coli  

Microsoft Academic Search

This work aims to produce 2-O-?-d-glucopyranosyl-l-ascorbic acid (AA-2G) from ascorbic acid and ?-cyclodextrin with immobilized ?-cyclodextrin glucanotransferase (?-CGTase) from recombinant Escherichia coli. Molecular sieve (SBA-15) was used as an adsorbent, and sodium alginate was used as a carrier, and glutaraldehyde (GA) was used as a cross-linker. The effects of several key variables on ?-CGTase immobilization were examined, and optimal immobilization

Zichen Zhang; Jianghua Li; Long Liu; Jun Sun; Zhaozhe Hua; Guocheng Du; Jian Chen

2011-01-01

252

p38 MAPK activation, JNK inhibition, neoplastic growth inhibition, and increased gap junction communication in human lung carcinoma and Ras-transformed cells by 4-phenyl-3-butenoic acid.  

PubMed

Human lung neoplasms frequently express mutations that down-regulate expression of various tumor suppressor molecules, including mitogen-activated protein kinases such as p38 MAPK. Conversely, activation of p38 MAPK in tumor cells results in cancer cell cycle inhibition or apoptosis initiated by chemotherapeutic agents such as retinoids or cisplatin, and is therefore an attractive approach for experimental anti-tumor therapies. We now report that 4-phenyl-3-butenoic acid (PBA), an experimental compound that reverses the transformed phenotype at non-cytotoxic concentrations, activates p38 MAPK in tumorigenic cells at concentrations and treatment times that correlate with decreased cell growth and increased cell-cell communication. H2009 human lung carcinoma cells and ras-transformed rat liver epithelial cells treated with PBA showed increased activation of p38 MAPK and its downstream effectors which occurred after 4?h and lasted beyond 48?h. Untransformed plasmid control cells showed low activation of p38 MAPK compared to ras-transformed and H2009 carcinoma cells, which correlates with the reduced effect of PBA on untransformed cell growth. The p38 MAPK inhibitor, SB203580, negated PBA's activation of p38 MAPK downstream effectors. PBA also increased cell-cell communication and connexin 43 phosphorylation in ras-transformed cells, which were prevented by SB203580. In addition, PBA decreased activation of JNK, which is upregulated in many cancers. Taken together, these results suggest that PBA exerts its growth regulatory effect in tumorigenic cells by concomitant up-regulation of p38 MAPK activity, altered connexin 43 expression, and down-regulation of JNK activity. PBA may therefore be an effective therapeutic agent in human cancers that exhibit down-regulated p38 MAPK activity and/or activated JNK and altered cell-cell communication. PMID:21898549

Matesic, Diane F; Sidorova, Tatyana S; Burns, Timothy J; Bell, Allison M; Tran, Paul L; Ruch, Randall J; May, Sheldon W

2012-01-01

253

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.

254

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

255

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

256

Asymmetric reduction of beta-ketonitriles with a recombinant carbonyl reductase and enzymatic transformation to optically pure beta-hydroxy carboxylic acids.  

PubMed

Alpha-ethylation is concomitant with the reduction of aromatic beta-ketonitriles catalyzed by whole-cell biocatalysts. Use of isolated carbonyl reductase has completely eliminated this competing reaction. (R)-beta-Hydroxy nitriles were obtained via a reduction catalyzed by a recombinant carbonyl reductase with excellent optical purity and were further converted to (R)-beta-hydroxy carboxylic acids via a nitrilase-catalyzed hydrolysis. The present study allows ready access to both chiral beta-hydroxy nitriles and beta-hydroxy carboxylic acids of pharmaceutical importance. PMID:17521195

Zhu, Dunming; Ankati, Haribabu; Mukherjee, Chandrani; Yang, Yan; Biehl, Edward R; Hua, Ling

2007-05-24

257

Transformations of Toxic Metals and Metalloids by Pseudomonas stutzeri Strain KC and its Siderophore Pyridine2,6-bis(thiocarboxylic acid)  

Microsoft Academic Search

\\u000a Pyridine-2,6-bis(thiocarboxylic acid)Pyridine-2,6-bis(thiocarboxylic acid) (pdtc)(pdtc) is a siderophore produced by Pseudomonas stutzeri KCPseudomonas stutzeri KC that plays a role in conditioning the bacterial environment. It serves as a siderophore in solubilizing\\u000a ferric iron and other micronutrient metals, and as a thiol-containing compound, it reacts with toxic heavy metals and metalloids,\\u000a reducing metals like Cr(VI), Se(IV), and Te(IV) and precipitating metals as

Anna M. Zawadzka; Andrzej J. Paszczynski; Ronald L. Crawford

258

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

259

Peroxyl radicals: Inductors of neurodegenerative and other inflammatory diseases. Their origin and how they transform cholesterol, phospholipids, plasmalogens, polyunsaturated fatty acids, sugars, and proteins into deleterious products  

Microsoft Academic Search

The most oxygen-sensitive constituents of cells are polyunsaturated fatty acids (PUFAs), which are incorporated in the outermost layer of cells in the form of phospholipids. PUFAs easily suffer oxidation. Identical marker compounds of these lipid peroxidation (LPO) processes are generated in both neurodegenerative and cardiovascular diseases, indicating a close relationship between the inducers of these events. Apparently, any alteration of

Gerhard Spiteller

2006-01-01

260

TERATOGENIC EFFECTS OF RETINOIC ACID ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR AND TRANSFORMING GROWTH FACTOR-ALPHA  

EPA Science Inventory

Background: EGF and TGF regulate cell proliferation and differentiation in the embryo. The induction of cleft palate (CP) by all trans retinoic acid (RA) was associated with altered expression of TGF, EGF receptor and binding of EGF. The present study uses knockout (KO) mice to e...

261

Temporal and spatial development of critical loads exceedance of acidity to Polish forest ecosystems in view of economic transformations and national environmental policy  

Microsoft Academic Search

Critical load exceedance is meant by definition as a quantitative measure of a potential risk of damage to ecosystems. Its temporal and spatial development for Polish forest ecosystems was a subject of a national scale study. Within this study critical loads of acidity were calculated and mapped and superimposed with sulphur and nitrogen deposition patterns of the last two decades.

Wojciech Mill

2006-01-01

262

ATR-FOURIER TRANSFORM MID-INFRARED SPECTROSCOPY FOR DETERMINATION OF TRANS FATTY ACIDS IN GROUND CEREAL PRODUCTS WITHOUT OIL EXTRACTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since FDA amended the rules for food labeling to include trans fatty acids (TFA), there has been a continued interest in development of optimized methods for determining TFA in foods. Traditional chromatographic methods are time-consuming and solvent based. Alternatively, spectroscopic methods invol...

263

Review of Papers Published in 1985 About Emission, Transport, Transformation and Deposition of Atmospheric Trace Constituents of Importance for Acid Deposition.  

National Technical Information Service (NTIS)

About 300 papers published in 1985 or later in 1984 have been reviewed. There has been progress in the development of models for acid deposition and photochemical oxidants. Simultaneous measurements of O/sub 3/, NO/sub x/, individual hydrocarbons, aldehyd...

O. Hov

1986-01-01

264

Transformations of Toxic Metals and Metalloids by Pseudomonas stutzeri Strain KC and its Siderophore Pyridine-2,6-bis(thiocarboxylic acid)  

NASA Astrophysics Data System (ADS)

Pyridine-2,6-bis(thiocarboxylic acid)Pyridine-2,6-bis(thiocarboxylic acid) (pdtc)(pdtc) is a siderophore produced by Pseudomonas stutzeri KCPseudomonas stutzeri KC that plays a role in conditioning the bacterial environment. It serves as a siderophore in solubilizing ferric iron and other micronutrient metals, and as a thiol-containing compound, it reacts with toxic heavy metals and metalloids, reducing metals like Cr(VI), Se(IV), and Te(IV) and precipitating metals as sulfides (e.g., Hg(II), Cd(II), Pb(II), and As(III)), rendering them insoluble and less toxic. Understanding the mechanism by which bacteria use pdtc to interact with metals may contribute to our understanding of metal cycling in the biosphere, and may have potential for use in bioremediationbioremediation of heavy metals.

Zawadzka, Anna M.; Paszczynski, Andrzej J.; Crawford, Ronald L.

265

In vitro pollen functionality of attacin-transgenic “Royal Gala” apple plants and apples transformed with 1-aminocyclopropane-1-carboxylic acid synthase (ACS)-antisense vector  

Microsoft Academic Search

To assess pollen functionality of transgenic apple trees, in vitro pollen germination and tube growth were evaluated. Flowers of transgenic “Royal Gala” apple lines containing attacin E gene to confer resistance to fire blight (Erwinia amylovora), or antisense 1-aminocyclopropane-1-carboxylic acid synthase (ACS) construct to improve fruit storage life, were collected, and pollen was harvested. Amongst the 19 transgenic lines, pollen from

K. Ko; S. K. Brown; J. L. Norelli; G. Hrazdina; H. S. Aldwinckle

2010-01-01

266

Comparative study of transformation of linear alkanes over modified mordenites and sulphated zirconia catalysts: Influence of the zeolite acidity on the performance of n-butane isomerization  

Microsoft Academic Search

Zeolite mordenite was dealuminated by steam treatment followed by acid leaching and further impregnated with 1wt.% of iron or sulphated. The various solids were characterized by XRD, 29Si and 27Al NMR, IR of adsorbed pyridine as well as ammonia adsorption calorimetry and evaluated in n-butane isomerization. BET surface area of non-dealuminated mordenite was 462m2g?1 and this value showed marked decreases

Alcineia C. Oliveira; Nadine Essayem; Alain Tuel; Jean-Marc Clacens; Younes Ben Tâarit

2008-01-01

267

Chemical Transformations, Molecular Transport, and Kinetic Barriers in Creating the Chiral Phase of ( R, R)Tartaric Acid on Cu(110)  

Microsoft Academic Search

Metal surfaces modified by chiral molecules have been shown to be effective heterogeneous catalysts for enantioselective reactions; however, their performance is found to be critically affected by modification conditions. Recently, model chirally modified surfaces created by the adsorption of the well-known chiral modifier, (R, R)-tartaric acid on a Cu(110) single crystal surface, have been shown to exhibit a variety of

M. Ortega Lorenzo; V. Humblot; P. Murray; C. J. Baddeley; S. Haq; R. Raval

2002-01-01

268

All trans-retinoic acid acts synergistically with hydroxytamoxifen and transforming-growth factor   to stimulate apoptosis in MCF7 breast cancer cells  

Microsoft Academic Search

The anti-estrogen 4-hydroxytamoxifen (TAM) and vita- min A-related compounds, the retinoids, in combination act synergistically to inhibit growth of breast cancer cells in vitro and in vivo. To clarify the mechanism of this synergism, the effect of TAM and all trans-retinoic acid (AT) on proliferation of MCF-7 breast cancer cells was studied in vitro. TAM and AT acted synergistically to

D N Danforth Jr

2004-01-01

269

Microbial utilization and transformation of humic acid-like substances extracted from a mixture of municipal refuse and sewage sludge disposed of in a landfill  

Microsoft Academic Search

The purpose of the research was to establish whether humic acid-like substances (HA) related to municipal refuse disposed of in a landfill can resist microbial degradation and if they contribute, in that way, to long-term stabilization of landfill refuse. Using a mixture of 0.1 M Na4P2O7 + 0.1 M NaOH, we extracted HA from municipal refuse mixed with sewage sludge

Z Filip; W Pecher; J Berthelin

2000-01-01

270

Insulin-like Growth Factor Binding Protein 3 Mediates Retinoic Acid and Transforming Growth Factor \\/32-induced Growth Inhibition in Human Breast Cancer Cells1  

Microsoft Academic Search

Retinoic acid (RA) is a potent in vitro inhibitor of cell proliferation in various malignant cell lines. The exact mechanisms of its actions, however, are not fully understood. To further elucidate the nature of this inhibition, we investigated the effects of RA in an estrogen receptor-negative human breast cancer cell line, MDA-MB-231. RA (0.01-5 \\/UM)significantly in hibited MDA-MB-231 cell growth

Zoran S. Gucev; Youngman Oh; Kevin M. Kelley; Ron G. Rosenfeld

271

Development of a multichannel Fourier-transform spectrometer to measure weak chemiluminescence: Application to the emission of singlet-oxygen dimol in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6  

NASA Astrophysics Data System (ADS)

A Fourier-transform spectrometer equipped with a Savart-plate polarization interferometer was developed for observation of weak chemiluminescence and applied to a measurement of emission spectra in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6]. The band appearing at ˜580 nm in the chemiluminescence spectrum was assigned to the emission of singlet-oxygen dimol, the peak wavelength being shifted from that observed in the reaction of hydrogen peroxide with sodium hypochlorite, ˜633 nm. The band intensity was increased with the increasing concentration of K 3[Fe(CN) 6] up to ˜100 mM, and thereafter the peak wavelength was shifted from 580 to 700 nm with a decrease in the intensity.

Tsukino, Kazuo; Satoh, Toshihiro; Ishii, Hiroshi; Nakata, Munetaka

2008-05-01

272

Studies on the identification of the heteropoly acid generated in the H 3PO 4–WO 3–Nb 2O 5 catalyst and its thermal transformation process  

Microsoft Academic Search

The precursor of the mixed metal oxide catalyst composed of H3PO4–WO3–Nb2O5, which exhibits excellent activity in Friedel–Crafts alkylations, was identified with 31P NMR. It was revealed that the Keggin-type mixed heteropoly acid, H4PNbW11O40, was spontaneously generated during preparation of the H3PO4–WO3–Nb2O5 catalyst. The partial decomposition of H4PNbW11O40 occurred in the temperature range of 673–823 K to give an amorphous oxide

Kazu Okumura; Katsuhiko Yamashita; Kazuhiro Yamada; Miki Niwa

2007-01-01

273

Synthesis of Stereodefined Piperidines from Aziridines and Their Transformation into Conformationally Constrained Amino Acids, Amino Alcohols and 2,7-Diazabicyclo[3.3.1]nonanes.  

PubMed

2-(2-Cyano-2-phenylethyl)aziridines were converted into novel cis- and trans-2-chloromethyl-4-phenylpiperidine-4-carbonitriles via alkylation with 1-bromo-2-chloroethane followed by microwave-assisted 6-exo-tet cyclization and regiospecific ring opening. The latter piperidines were used as eligible substrates for the synthesis of stereodefined 2-chloromethyl-, 2-hydroxymethyl-, and 2-carboxymethyl-4-phenylpiperidine-4-carboxylic acids, 2-hydroxymethyl-4-phenylpiperidine-4-carbonitriles, 3-hydroxy-5-phenylazepane-5-carbonitriles, and 5-phenyl-2,7-diazabicyclo[3.3.1]nonanes. PMID:20977252

Vervisch, Karel; D'hooghe, Matthias; To?rnroos, Karl W; De Kimpe, Norbert

2010-10-26

274

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

275

Genetic Transformation in the Genus Pasteurella.  

National Technical Information Service (NTIS)

Streptomycin-sensitive cultures of Pasteurella novicida can be transformed by deoxyribonucleic acid (DNA) extracted from streptomycin-resistant cultures of P. novicida or P. tularensis. Similarly, cultures nutritionally dependent on tryptophan or adenine ...

F. J. Tyeryar W. D. Lawton

1970-01-01

276

Relationships of a transforming growth factor-beta2 single nucleotide polymorphism and messenger ribonucleic acid abundance with bone and production traits in chickens.  

PubMed

Osteoporosis is a serious problem for the laying hen industry with economic, production, and welfare consequences. Transforming growth factor-beta2 (TGFbeta2) has been implicated as an important factor in coupling bone resorption and formation in bone remodeling. The current study was designed to determine if TGFbeta2 was associated with variation in bone mineralization in chickens, using 2 complementary experimental approaches. First, an intronic single nucleotide polymorphism (SNP) present in TGFbeta2 was investigated in an F(2) population to determine its association with bone, growth, and egg traits of importance to the layer and broiler industries. The TGFbeta2 SNP was significantly associated (P < 0.05) with bone mineral density and content. However, these associations became nonsignificant when BW was included as a covariate in analyses. The TGFbeta2 SNP was also significantly associated (P < 0.05) with BW from 1 to 6 wk of age and egg production from 46 to 55 wk of age. To further explore the relationship between TGFbeta2 and bone strength, bone marrow TGFbeta2 mRNA abundance was compared between broiler and layer chickens at 15, 35, and 60 wk of age. Bone and egg traits were measured along with mRNA abundance at each age and found to differ significantly between lines. The TGFbeta2 mRNA abundance was approximately 4-fold greater in broiler compared with layer hens at 15 wk of age but was similar between lines at later ages. Thus, even though the TGFbeta2 SNP will likely not be an effective marker for improving bone strength independently of changes in BW, further research is warranted to investigate the relationship of TGFbeta2 mRNA abundance to bone strength in laying hens. PMID:17435015

Bennett, A K; Hester, P Y; Spurlock, D M

2007-05-01

277

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

278

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

279

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy. Phase 1, September 29, 1990--September 30, 1991  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 {times} 10{sup 14} BTU/yr.

Bullin, J.A.; Frazier, R.E.

1991-09-01

280

Collection of VLE data for acid gas---alkanolamine systems using fourier transform infrared spectroscopy. Phase 2, October 1, 1991--September 30, 1992  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor--liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor--liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 {times} 10{sup 14} BTU/yr.

Bullin, J.A.; Frazier, R.E.

1992-12-01

281

Microbial utilization and transformation of humic acid-like substances extracted from a mixture of municipal refuse and sewage sludge disposed of in a landfill.  

PubMed

The purpose of the research was to establish whether humic acid-like substances (HA) related to municipal refuse disposed of in a landfill can resist microbial degradation and if they contribute, in that way, to long-term stabilization of landfill refuse. Using a mixture of 0.1 M Na(4)P(2)O(7) + 0.1 M NaOH, we extracted HA from municipal refuse mixed with sewage sludge and disposed of for up to 12 months, in a 40-m(3) model landfill. In laboratory experiments under aerobic conditions, up to 50% of HA was utilized as a supplementary source of nutrients by an assemblage of soil microorganisms in only 21 days. The microbial utilization was enhanced to over 80%, and up to 98%, respectively, if HA served as the sole source of carbon or nitrogen. Remaining HA which could be re-isolated from microbial cultures were lower in carbon (<12%) and nitrogen (<2.3%). Spectroscopic analysis (UV, Vis, FTIR) indicated losses, especially in aliphatic structural units, and a relative enhancement in aromatic structures. It was postulated that for their high degree of degradability, HA indigenous to that anthropogenic environment would not play an important role in the long-term stabilization of landfill refuse. PMID:15092916

Filip, Z; Pecher, W; Berthelin, J

2000-07-01

282

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

283

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

284

p53 domains: suppression, transformation, and transactivation.  

PubMed

We investigated the suppression, transformation, and transactivation functions of isolated segments of wild-type murine p53. Intact p53, but no segment of p53, inhibited cellular transformation by the activated ras and adenovirus E1A proteins. We conclude that most of p53 is needed for suppression of cellular proliferation. Nevertheless, the transactivating domain of herpesvirus protein VP16 was able to substitute for the N-terminal transactivating domain of p53 in cellular suppression. Thus, unless the interchanged p53 and VP16 acidic segments share additional functions, transactivation is required for suppression by p53. Interestingly, we found that all p53 segments containing amino acids 320-360 enhanced transformation by ras and E1A. This region has been associated with the oligomerization of p53 (Milner et al., 1991; Sturzbecher et al., 1992). Furthermore, no p53 segment lacking amino acids 320-360 transformed cells. Amino acids 320-360, therefore, may account for the major transforming activity of p53. Intact p53 and chimeric VP16-p53 transactivated the CAT gene under control of a p53-specific promoter, while transforming segments of p53 interfered with transactivation by wild-type p53. Our findings argue that transactivation by p53 is required for cellular suppression and that any nontransactivating p53 that retains the capacity to oligomerize with wild-type p53 would have transformation potential. PMID:8508031

Reed, M; Wang, Y; Mayr, G; Anderson, M E; Schwedes, J F; Tegtmeyer, P

1993-01-01

285

Factors Affecting Transformation of Bacillus licheniformis  

PubMed Central

Thorne, Curtis B. (Fort Detrick, Frederick, Md.), and Harold B. Stull. Factors affecting transformation of Bacillus licheniformis. J. Bacteriol. 91:1012–1020. 1966.—Transformation systems involving two types of transformable mutants of Bacillus licheniformis 9945A were compared. Each system required its specific growth medium, but a single transformation medium could be used for both. Cells from a culture of optimal age were not competent, at least to any great extent, but they developed competence during incubation in a transformation medium. With each system, 3 to 5% of the recipient cells were transformed upon exposure to wild-type deoxyribonucleic acid (DNA) for 2 to 3 hr. When competent cells were exposed to DNA for 30 min, 1 to 2% of them were transformed. The data are interpreted to mean that cells were heterogeneous with respect to development of competence, and when properly grown cells were incubated in transformation medium some of them gained competence, whereas others lost it. If DNA was present during the entire period, the cells were transformed as they became competent and the transformants accumulated. However, during any short period of exposure to DNA, only those cells that were competent at the time were potential transformants. The high frequencies of transformation obtained in these studies made it feasible to prepare marked strains by transforming markers into recipient cells. These experiments demonstrated that the characteristics of the two transformation systems could not be attributed to specific nutritional markers. Presumably, each of the two series of highly transformable auxotrophic mutants also carried at least one other mutation that resulted in development of competence under the specific conditions.

Thorne, Curtis B.; Stull, Harold B.

1966-01-01

286

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

287

PHASE TRANSFORMATIONS IN ALUMINA. Technical Report, May to December 1961  

Microsoft Academic Search

e transformation studies showed that synthetic aluminas produced in ; the laboratory were not transformed to alpha alumina at 400 to 700' deg n the ; presence of nitric acid and water vapor. Amorphous aluminn produced in the pilot ; plant was transformed to alpha alumina. This indicated that the amorphous ; alumina produced in the pilot plant is structurally

H. J. Eding; M. L. Huggins; A. G. Brown

1961-01-01

288

Myb-Ets fusion oncoprotein inhibits thyroid hormone receptor/c-ErbA and retinoic acid receptor functions: a novel mechanism of action for leukemogenic transformation by E26 avian retrovirus.  

PubMed Central

The E26 and avian erythroblastosis virus (AEV) avian retroviruses induce acute leukemia in chickens. E26 can block both erythroid and myeloid differentiation at an early multipotent stage. Moreover, E26 can block erythroid differentiation at the erythroid burst-forming unit/erythroid CFU (BFU-E/CFU-E) stage, which also corresponds to the differentiation stage blocked by AEV. AEV carries two oncogenes, v-erbA and v-erbB, whereas E26 encodes a single 135-kDa Gag-Myb-Ets fusion oncoprotein. v-ErbA is responsible for the erythroid differentiation arrest through negative interferences with both the retinoic acid receptor (RAR) and the thyroid hormone receptor (T3R/c-ErbA). We investigated whether Myb-Ets could block erythroid differentiation in a manner similar to v-ErbA. We show here that Myb-Ets inhibits both RAR and c-ErbA activities on specific hormone response elements in transient-expression assays. Moreover, Myb-Ets abrogates the inactivation of transcription factor AP-1 by RAR and T3R, another feature shared with v-ErbA. Myb-Ets also antagonizes the biological response of erythrocytic progenitor cells to retinoic acid and T3. Analysis of a series of mutants of Myb-Ets reveals that the domains of the oncoprotein involved in these inhibitory activities are the same as those involved in oncogenic transformation of hematopoietic cells. These data demonstrate that the Myb-Ets oncoprotein shares properties with the v-ErbA oncoprotein and that inhibition of ligand-dependent RAR and c-ErbA functions by Myb-Ets is responsible for blocking the differentiation of hematopoietic progenitors.

Rascle, A; Ferrand, N; Gandrillon, O; Samarut, J

1996-01-01

289

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

290

Hadamard transform imaging  

SciTech Connect

We have constructed a Hadamard transform Raman microscopic imaging system, and have developed it to a high definition (64K pixel) technique. We have demonstrated multispectral Raman imaging and developed the first three-dimensional (digital confocal) Raman imaging. We have explored the systematic errors in Hadamard multiplexing techniques and developed corrections. We have used our Raman microscope techniques to explore defect distributions on graphite electrodes and damage effects on SERS-activated silver electrodes. We have used the microprobe capabilities of our instrument to investigate the kinetics of polyacrylamide formation in electrolysis capabilities. We have worked closely with a manufacture of holographic displays to develop and incorporate holographic filters and holographic beam splitters into Raman spectrographs and microscopes. Finally, we have developed Hadamard multiplexing techniques for densitometric measurements of protein or nucleic acid blots.

Morris, M.D.

1992-01-01

291

The third member of the transforming acidic coiled coil-containing gene family, TACC3, maps in 4p16, close to translocation breakpoints in multiple myeloma, and is upregulated in various cancer cell lines.  

PubMed

We have recently identified a novel gene, TACC1 (transforming acidic coiled coil-containing gene 1), which is located close to FGFR1 within a region amplified in breast cancer on human chromosome 8p11. The coiled coil domain of this gene identified a series of cDNAs in the expressed sequence tag database, which suggested the existence of a family of TACC genes comprising at least three family members. We have now characterized the human and mouse TACC3 cDNAs, and demonstrate that this gene is upregulated in various cancer cell lines, and at Embryonic Day 15 in mice, suggesting that the TACC3 protein is involved in the control of cell growth and differentiation. The TACC3 gene maps telomeric to the FGFR3 gene in 4p16.3, close to a region disrupted by translocation breakpoints associated with multiple myeloma. Thus, TACC1, TACC2, and TACC3 map close to the corresponding FGFR1, FGFR2, and FGFR3 genes. The phylogenetic relationship among the three TACC genes is similar to that of the three FGFR family members. These relationships suggest that the FGFR and TACC genes arose from a physically linked ancestral gene pair. Subsequently, this gene pair has undergone two successive rounds of gene duplication to give rise to the three FGFR/TACC gene pairs on chromosomes 4, 8, and 10. PMID:10366448

Still, I H; Vince, P; Cowell, J K

1999-06-01

292

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

293

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

294

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

295

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

296

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

297

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

298

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

299

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

300

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

301

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

302

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

303

Transformation of Haemophilus influenzae by plasmid RSF0885  

SciTech Connect

Plasmid RSF0885, which conferred ampicillin resistance, transformed competent Haemophilus influenzae cells with low efficiency (maximun, less than 0.01%). As judged by competition experiments and uptake of radioactivity, plasmid RSF0885 deoxyribonucleic acid was taken up into competent H. influenzae cells several orders of magnitude less efficiently than H. influenzae chromosomal deoxyribonucleic acid. Plasmid RSF0885 transformed cells with even lower efficiency than could be accounted for by the low uptake. Transformation was not affected by rec-1 and rec-2 mutations in the recipient, and strains cured of the plasmid did not show increased transformation. Plasmid molecules cut once with a restriction enzyme that made blunt ends did not transform. Transformation was favored by the closed circular form of the plasmid.

Notani, N.K.; Setlow, J.K.; McCarthy, D.; Clayton, N.L.

1981-12-01

304

Electrical impedance measurements predict cellular transformation.  

PubMed

Cellular transformation is the first step in cancer development. Two features of cellular transformation are proliferation in reduced serum and loss of contact inhibition. Electronic Cell-Substrate Impedance Sensing (ECIS) measurements have been used to measure cellular proliferation, cytotoxicity, apoptosis, and attachment. We have used impedance measurements to distinguish normal cells from cells transformed with a constitutively active chemokine receptor, CXCR2. CXCR2, a member of the G-protein coupled receptor (GPCR) family, is normally involved in cellular activation and migration, but a single amino acid substitution leads to constitutive activity. NIH3T3 cells were transformed with a constitutively active CXCR2 (D143V_CXCR2) and growth in reduced serum and foci formation were measured using established biological assays and compared to data from ECIS. The results of this study show that impedance measurements provide a quick and reliable way of measuring cellular transformation and provide real time assessment of transformed cellular parameters. Use of the ECIS system could allow a rapid screening of anti-cancer drugs that alter cellular transformation. PMID:19356706

Park, Giljun; Choi, Chang K; English, Anthony E; Sparer, Tim E

2009-01-27

305

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

306

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

307

Chemoporation using saponins or cholates: an alternative method for transformation of bacterial cells  

Microsoft Academic Search

A new method for fast transformation of competent bacterial cells has been developed. The transformation is induced with cholic\\u000a acid analogues or saponins which cause reversible disruption of the bacterial membrane. This method shortens the time of transformation\\u000a without significant loss of transformation efficiency in comparison to heat shock method and is the first reported chemically-induced\\u000a transformation. New data about

Matjaž Ravnikar; Andreja Irman; Nataša Radi?; Mojca Lunder; Borut Štrukelj

2009-01-01

308

Artemisinin production by transformed roots of Artemisia annua  

Microsoft Academic Search

Transformed root cultures of several strains of Artemisia annua were obtained by infection with Agrobacterium rhizogenes ATCC 15834. Production of artemisinin, measured by HPLC, ranged from 0–0.42 % of dry weight (DW) in 10 different clones. Artemistene, artemisinic acid, and arteannuin B were also measured. Comparisons to literature reports suggest that the commercial production of artemisinic compounds using transformed roots

P. J. Weathers; R. D. Cheetham; E. Follansbee; K. Teoh

1994-01-01

309

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

310

Transformation of Haemophilus influenzae by plasmid RSF0885  

Microsoft Academic Search

Plasmid RSF0885, which conferred ampicillin resistance, transformed competent Haemophilus influenzae cells with low efficiency (maximun, less than 0.01%). As judged by competition experiments and uptake of radioactivity, plasmid RSF0885 deoxyribonucleic acid was taken up into competent H. influenzae cells several orders of magnitude less efficiently than H. influenzae chromosomal deoxyribonucleic acid. Plasmid RSF0885 transformed cells with even lower efficiency than

N. K. Notani; J. K. Setlow; D. McCarthy; N. L. Clayton

1981-01-01

311

Cell Response to Nucleic Acid Penetration.  

National Technical Information Service (NTIS)

Employing the Haemophilus influenzae bacterial transformation system, the immediate response of cells to the penetration by nucleic acids is being analyzed. The investigation involves the study of the fate of absorbed nucleic acids, especially their degra...

J. H. Stuy

1969-01-01

312

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

313

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

314

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

315

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

316

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

317

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

318

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

319

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

320

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

321

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

322

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

323

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

324

Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants  

Microsoft Academic Search

The present invention relates to a process for producing lipids containing the fatty acid, petroselinic acid, in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a Ï12 desaturase from another species which does normally accumulate petroselinic acid. 19 figs.

J. B. Ohlrogge; E. B. Cahoon; J. Shanklin; C. R. Somerville

1995-01-01

325

Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants  

DOEpatents

The present invention relates to a process for producing lipids containing the fatty acid, petroselinic acid, in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a {omega}12 desaturase from another species which does normally accumulate petroselinic acid. 19 figs.

Ohlrogge, J.B.; Cahoon, E.B.; Shanklin, J.; Somerville, C.R.

1995-07-04

326

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

327

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

328

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

329

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

330

[Agrobacterium rhizogenes-mediated transformation and the regeneration of transformants in Alhagi pseudalhagi].  

PubMed

The regenerated shoot segments of Alhagi pseudalhagi were sliced and infected with Agrobacterium rhizogenes strain A4. The hairy roots and transformed calli were obtained through selection on hormone free MS medium. The transformants were cultured on MS medium with 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5-1 mg/L 6-benzylaminopurine (6-BA) to induce calli. 3 mg/L 6-BA and 0.5 mg/L naphthalene acetic acid (NAA) were applied for shoot differentiation. Shoots were planted on MS medium with 2 mg/L indole-3-butyric acid (IBA) and produced roots. Opine analysis proved the integration and expression of T-DNA in over 95% hairy roots, 75% transformed calli and transformed plantlets respectively. The 81% hairy root cells had normal chromosome numbers (2n = 18). The alterations of chromosome number were observed. After one year of subculturing, the regeneration ability of transformants was maintained. PMID:12549099

Bu, H Y; Jing, J Z; Jia, J F

2001-06-01

331

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

332

Ursodeoxycholic acid, 7-ketolithocholic acid, and chenodeoxycholic acid are primary bile acids of the nutria (Myocastor coypus).  

PubMed

Because ursodeoxycholic and chenodeoxycholic acids are interconverted in humans via 7-ketolithocholic acid, bile acid metabolism was studied in the nutria (Myocastor coypus), the bile of which is known to contain these three bile acids. Relative concentrations of ursodeoxycholic (37% +/- 20%), 7-ketolithocholic (33% +/- 17%), and chenodeoxycholic (17% +/- 9%) acids in gallbladder bile were unchanged by 5-20 h of complete biliary diversion (n = 7). Injection of either [14C]cholesterol, [14C]ursodeoxycholic, [14C]7-ketolithocholic acid, or a mixture of [7 beta-3H]chenodeoxycholic acid and [14C]chenodeoxycholic acid into bile fistula nutria demonstrated that all three bile acids can be synthesized hepatically from cholesterol, that they are interconverted sparingly (2%-5%) by the liver, but that 7-ketolithocholic acid is an intermediate in the hepatic transformation of chenodeoxycholic acid to ursodeoxycholic acid. An animal that had been fed antibiotics showed an unusually elevated concentration of ursodeoxycholic acid in gallbladder and hepatic bile, suggesting that bacterial transformation of ursodeoxycholic acid in the intestine may be a source of some biliary chenodeoxycholic acid and 7-ketolithocholic acid. PMID:3943698

Tint, G S; Bullock, J; Batta, A K; Shefer, S; Salen, G

1986-03-01

333

Levulinic acid in organic synthesis  

NASA Astrophysics Data System (ADS)

Data concerning the methods of synthesis, chemical transformations and application of levulinic acid are analysed and generalised. The wide synthetic potential of levulinic acid, particularly as a key compound in the synthesis of various heterocyclic systems, saturated and unsaturated ketones and diketones, difficultly accessible acids and other compounds is demonstrated. The accessibility of levulinic acid from hexose-containing wood-processing and agricultural wastes is noted. The bibliography includes 260 references.

Timokhin, Boris V.; Baransky, V. A.; Eliseeva, G. D.

1999-01-01

334

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

335

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.

336

Gas-phase Acidities of Aspartic Acid, Glutamic Acid, and their Amino Acid Amides.  

SciTech Connect

Gas-phase acidities (GA or ?Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage’s importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3–4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2? group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

Li, Zhong; Matus, Myrna H.; Velazquez, Hector A.; Dixon, David A.; Cassady, Carolyn J.

2007-02-14

337

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

338

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

339

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

340

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

341

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

342

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

343

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

344

Galectin-1 binds oncogenic H-Ras to mediate Ras membrane anchorage and cell transformation  

Microsoft Academic Search

Ras genes, frequently mutated in human tumors, promote malignant transformation. Ras transformation requires membrane anchorage, which is promoted by Ras farnesylcysteine carboxymethylester and by a second signal. Previously we showed that the farnesylcysteine mimetic, farnesylthiosalicylic acid (FTS) disrupts Ras membrane anchorage. To understand how this disruption contributes to inhibition of cell transformation we searched for new Ras-interacting proteins and identified

Ariella Paz; Roni Haklai; Galit Elad-Sfadia; Eyal Ballan; Yoel Kloog

2001-01-01

345

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

346

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

347

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

348

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.

349

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

350

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

351

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

352

REVERSIBLE INACTIVATION OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES  

PubMed Central

1. The transforming substance of Pneumococcus Type III is inactivated by treatment with ascorbic acid. This effect of ascorbic acid is catalyzed by traces of cupric ion and is prevented by the presence of sulfhydryl compounds. 2. Under certain conditions, the activity of transforming substance treated with ascorbic acid can be restored by the use of glutathione and other sulfhydryl compounds. 3. Other compounds, such as catechol, hydroquinone, and p-phenylenediamine, which undergo autoxidation similar to that of ascorbic acid, have an analogous effect on the transforming substance. 4. The effect of these compounds on the transforming substance is nullified by exclusion of oxygen or by the use of catalase. 5. It is concluded that inactivation of the transforming substance is probably oxidative in character and depends on the formation of peroxides in the course of autoxidation of ascorbic acid or related compounds. 6. The relation of this phenomenon to that of the inactivation of other biologically active substances by ascorbic acid is discussed.

McCarty, Maclyn

1945-01-01

353

Design of zeolite by inverse sigma transformation  

NASA Astrophysics Data System (ADS)

Although the search for new zeolites has traditionally been based on trial and error, more rational methods are now available. The theoretical concept of inverse ? transformation of a zeolite framework to generate a new structure by removal of a layer of framework atoms and contraction has for the first time been achieved experimentally. The reactivity of framework germanium atoms in strong mineral acid was exploited to selectively remove germanium-containing four-ring units from an UTL type germanosilicate zeolite. Annealing of the leached framework through calcination led to the new all-silica COK-14 zeolite with intersecting 12- and 10-membered ring channel systems. An intermediate stage of this inverse ? transformation with dislodged germanate four-rings still residing in the pores could be demonstrated. Inverse ? transformation involving elimination of germanium-containing structural units opens perspectives for the synthesis of many more zeolites.

Verheyen, Elke; Joos, Lennart; van Havenbergh, Kristof; Breynaert, Eric; Kasian, Nataliia; Gobechiya, Elena; Houthoofd, Kristof; Martineau, Charlotte; Hinterstein, Manuel; Taulelle, Francis; van Speybroeck, Veronique; Waroquier, Michel; Bals, Sara; van Tendeloo, Gustaaf; Kirschhock, Christine E. A.; Martens, Johan A.

2012-12-01

354

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

355

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

356

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

357

Transformation of phenol into phenylalanine by a methanogenic consortium  

SciTech Connect

Phenol is a widely used chemical found in many wastewaters of industrial origin. The degradation of phenol by methanogenic bacterial consortia has been reported by many investigators. To better characterise the metabolism of this consortium, a new metabolic pathway of benzoic acid, an intermediary in the degradation of phenol, is reported. This study describes the transformations of benzoic acid into 3-phenylpropionic acid and phenylalanine. 25 refs., 5 figs.

Lepine, F.; Milot, S.; Beaudet, R.; Villemur, R. [Universite du Quebec, Laval (Canada)] [and others

1996-03-01

358

[Efficient Agrobacterium-mediated transformation of soybean].  

PubMed

To improve Agrobacterium tumefaciens mediated transformation of embryonic tips of soybean [Glycine max (L.) Merr], the effect of several factors on transformation efficiency were examined by measuring transient expression levels of beta-glucuronidase and the number of resistant explants. The hypervirulent Agrobacterium tumefaciens strain KYRT1 was proved to be a better transformer than EHA105 and LBA4404. Improved transformation efficiencies were obtained when embryonic tips were incubated with an Agrobacterium suspension (A600=0.5) for 20 h. Optimized co-cultivation was performed in acidic medium (pH 5.4) at 22 degrees C in the dark for 5 days. Resting culture and step-by-step selection culture were beneficial to the survial of resistant explants. By combining the best treatments, transgenic soybeans of seven cultivars were obtained that simultaneously express the cryIA (c) and Pinellia ternata agglutinins (pta) genes. Most of the transgenic plants (about 70%) are fertile. The transformation frequency [(the number of PCR-positive regenerated plants/the number of infected explants) x 100%] ranged from 4.29% to 18.0%. PCR and Southern analyses confirmed the stable integration of the binary insect resistance genes in the primary transgenic plants. PMID:17674770

Dang, Wei; Wei, Zhi Ming

2007-06-01

359

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

360

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

361

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

362

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

363

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

364

Synthesis of axially chiral amino acid and amino alcohols via additive-ligand-free Pd-catalyzed domino coupling reaction and subsequent transformations of the product amidoaza[5]helicene.  

PubMed

Novel optically active axially chiral amino acid and amino alcohols have been synthesized efficiently via lactam ring-opening, with the aid of an optically active alcohol, amidoaza[5]helicene 5, which has been readily prepared by an additive-ligand-free Pd catalyzed domino coupling reaction in a single step. The stereostructures of these chiral molecules have also been clarified. PMID:20839825

Furuta, Takumi; Yamamoto, Junya; Kitamura, Yuki; Hashimoto, Ayano; Masu, Hyuma; Azumaya, Isao; Kan, Toshiyuki; Kawabata, Takeo

2010-10-15

365

[Studies on interaction of acid-treated nanotube titanic acid and amino acids].  

PubMed

Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination. PMID:20649031

Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

2010-06-01

366

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

367

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

368

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-hydroxyandrost-4-ene-3,11-dione (3) and 17beta-hydroxyandrosta-1,4-diene-3,11-dione (4). The fermentation of 1 with Fusarium lini also produced metabolites 2 and 4, while the fermentation with Trichothecium roseum afforded metabolite 3. The structures of transformed products were determined by spectroscopic methods. PMID:12434991

Musharraf, S Ghulam; Atta-Ur-Rahman; Choudhary, M Iqbal; Sultan, Sadia

2002-10-01

369

Transformation of Follicular Lymphoma  

PubMed Central

Histological transformation of follicular lymphoma (FL) to a more aggressive non-Hodgkin's lymphomas is a pivotal event in the natural history of FL and is associated with poor outcome. While commonly observed in clinical practice and despite multiple studies designed to address its pathogenesis, the biology of this process represents an enigma. In this chapter we present a state of the art review summarizing the definition of histologic transformation, its incidence, pathogenesis, clinical manifestations, treatment and outcome. Furthermore, we specifically emphasize gaps in our knowledge that should be addressed in future studies.

Lossos, Izidore S.; Gascoyne, Randy D.

2011-01-01

370

Genetic transformation of switchgrass.  

PubMed

Switchgrass (Panicum virgatum L.) is a highly productive warm-season C4 species that is being developed into a dedicated biofuel crop. This chapter describes a protocol that allows the generation of transgenic switchgrass plants by Agrobacterium tumefaciens-mediated transformation. Embryogenic calluses induced from caryopses or inflorescences were used as explants for inoculation with A. tumefaciens strain EHA105. Hygromycin phosphotransferase gene (hph) was used as the selectable marker and hygromycin was used as the selection agent. Calluses resistant to hygromycin were obtained after 5-6 weeks of selection. Soil-grown switchgrass plants were regenerated about 6 months after callus induction and Agrobacterium-mediated transformation. PMID:19768615

Xi, Yajun; Ge, Yaxin; Wang, Zeng-Yu

2009-01-01

371

Genetic Transformation of Switchgrass  

NASA Astrophysics Data System (ADS)

Switchgrass (Panicum virgatum L.) is a highly productive warm-season C4 species that is being developed into a dedicated biofuel crop. This chapter describes a protocol that allows the generation of transgenic switchgrass plants by Agrobacterium tumefaciens-mediated transformation. Embryogenic calluses induced from caryopses or inflorescences were used as explants for inoculation with A. tumefaciens strain EHA105. Hygromycin phosphotransferase gene (hph) was used as the selectable marker and hygromycin was used as the selection agent. Calluses resistant to hygromycin were obtained after 5-6 weeks of selection. Soil-grown switchgrass plants were regenerated about 6 months after callus induction and Agrobacterium-mediated transformation.

Xi, Yajun; Ge, Yaxin; Wang, Zeng-Yu

372

p53 domains: structure, oligomerization, and transformation.  

PubMed Central

Wild-type p53 forms tetramers and multiples of tetramers. Friedman et al. (P. N. Friedman, X. B. Chen, J. Bargonetti, and C. Prives, Proc. Natl. Acad. Sci. USA 90:3319-3323, 1993) have reported that human p53 behaves as a larger molecule during gel filtration than it does during sucrose gradient sedimentation. These differences argue that wild-type p53 has a nonglobular shape. To identify structural and oligomerization domains in p53, we have investigated the physical properties of purified segments of p53. The central, specific DNA-binding domain within murine amino acids 80 to 320 and human amino acids 83 to 323 behaves predominantly as monomers during analysis by sedimentation, gel filtration, and gel electrophoresis. This consistent behavior argues that the central region of p53 is globular in shape. Under appropriate conditions, however, this segment can form transient oligomers without apparent preference for a single oligomeric structure. This region does not enhance transformation by other oncogenes. The biological implications of transient oligomerization by this central segment, therefore, remain to be demonstrated. Like wild-type p53, the C terminus, consisting of murine amino acids 280 to 390 and human amino acids 283 to 393, behaves anomalously during gel filtration and apparently has a nonglobular shape. Within this region, murine amino acids 315 to 350 and human amino acids 323 to 355 are sufficient for assembly of stable tetramers. The finding that murine amino acids 315 to 360 enhance transformation by other oncogenes strongly supports the role of p53 tetramerization in oncogenesis. Amino acids 330 to 390 of murine p53 and amino acids 340 to 393 of human p53, which have been implicated by Sturzbecher et al. in tetramerization (H.-W. Sturzbecher, R. Brain, C. Addison, K. Rudge, M. Remm, M. Grimaldi, E. Keenan, and J. R. Jenkins, Oncogene 7:1513-1523, 1992), do not form stable tetramers under our conditions. Our findings indicate that p53 has at least two autonomous oligomerization domains: a strong tetramerization domain in its C-terminal region and a weaker oligomerization domain in the central DNA binding region of p53. Together, these domains account for the formation of tetramers and multiples of tetramers by wild-type p53. The tetramerization domain is the major determinant of the dominant negative phenotype leading to transformation by mutant p53s. Images

Wang, P; Reed, M; Wang, Y; Mayr, G; Stenger, J E; Anderson, M E; Schwedes, J F; Tegtmeyer, P

1994-01-01

373

p53 domains: structure, oligomerization, and transformation.  

PubMed

Wild-type p53 forms tetramers and multiples of tetramers. Friedman et al. (P. N. Friedman, X. B. Chen, J. Bargonetti, and C. Prives, Proc. Natl. Acad. Sci. USA 90:3319-3323, 1993) have reported that human p53 behaves as a larger molecule during gel filtration than it does during sucrose gradient sedimentation. These differences argue that wild-type p53 has a nonglobular shape. To identify structural and oligomerization domains in p53, we have investigated the physical properties of purified segments of p53. The central, specific DNA-binding domain within murine amino acids 80 to 320 and human amino acids 83 to 323 behaves predominantly as monomers during analysis by sedimentation, gel filtration, and gel electrophoresis. This consistent behavior argues that the central region of p53 is globular in shape. Under appropriate conditions, however, this segment can form transient oligomers without apparent preference for a single oligomeric structure. This region does not enhance transformation by other oncogenes. The biological implications of transient oligomerization by this central segment, therefore, remain to be demonstrated. Like wild-type p53, the C terminus, consisting of murine amino acids 280 to 390 and human amino acids 283 to 393, behaves anomalously during gel filtration and apparently has a nonglobular shape. Within this region, murine amino acids 315 to 350 and human amino acids 323 to 355 are sufficient for assembly of stable tetramers. The finding that murine amino acids 315 to 360 enhance transformation by other oncogenes strongly supports the role of p53 tetramerization in oncogenesis. Amino acids 330 to 390 of murine p53 and amino acids 340 to 393 of human p53, which have been implicated by Sturzbecher et al. in tetramerization (H.-W. Sturzbecher, R. Brain, C. Addison, K. Rudge, M. Remm, M. Grimaldi, E. Keenan, and J. R. Jenkins, Oncogene 7:1513-1523, 1992), do not form stable tetramers under our conditions. Our findings indicate that p53 has at least two autonomous oligomerization domains: a strong tetramerization domain in its C-terminal region and a weaker oligomerization domain in the central DNA binding region of p53. Together, these domains account for the formation of tetramers and multiples of tetramers by wild-type p53. The tetramerization domain is the major determinant of the dominant negative phenotype leading to transformation by mutant p53s. PMID:8035799

Wang, P; Reed, M; Wang, Y; Mayr, G; Stenger, J E; Anderson, M E; Schwedes, J F; Tegtmeyer, P

1994-08-01

374

Radiation-inactivation size of transformed and non-transformed androgen receptors.  

PubMed Central

The nucleic acid sequence of the androgen receptor (AR) gene predicts that the protein structure possesses DNA- and steroid-binding domains that show high degrees of sequence similarity with those of other steroid receptors. Since the steroid-binding domain of the AR corresponds to a 30 kDa portion of the protein, and the AR structure may be monomeric or hetero-oligomeric depending on its transformation state, we have herein determined the AR radiation-inactivation size (RIS) in relation to the molecular structure whose binding activity toward methyltrienolone (R1881) is abolished by a radiation 'hit'. Soluble fractions from whole canine prostatic tissue were used as a source of non-transformed AR. The AR transformation was induced by the addition of 0.6 M-KCl, and these preparations were used together with high-salt nuclear extracts as a source of transformed AR. To maximize the binding activity, molybdate and dithiothreitol were included during AR extraction. Receptor transformation was verified by modifications of both the sedimentation coefficients (from 7.5 S to 4.1 S on sucrose gradients) and molecular masses (from 260 kDa to 115 kDa by gel filtration). The RIS values of the non-transformed and transformed ARs were not statistically different: 92 +/- 19 kDa and 110 +/- 25 kDa respectively. In addition, the inactivation of AR binding activity by radiation was attributed to a loss of binding sites, with no significant change in the Kd. When benzoic acid, a free-electron scavenger, was added together with dithiothreitol before and after irradiation, no change in the RIS value was observed. Thus, in the canine prostate, the RIS value of the AR represents the monomeric protein, independently of its association with other proteins, and this value corresponds to that predicted by cloning studies and photoaffinity-labelling of AR.

Turcotte, G; Beauregard, G; Potier, M; Chevalier, S

1991-01-01

375

Model Transformations in Practice Workshop  

Microsoft Academic Search

\\u000a Model Transformations in Practice (MTiP) 2005 was a workshop which provided a forum for the model transformation community\\u000a to discuss practical model transformation issues. Although many different model transformation approaches have been proposed\\u000a and explored in recent years, there has been little work on comparing and contrasting various approaches. Without such comparisons,\\u000a it is hard to assess new model transformation

Jean Bézivin; Bernhard Rumpe; Andy Schürr; Laurence Tratt

2005-01-01

376

The effects of pH, ionic strength, and iron–fulvic acid interactions on the kinetics of non-photochemical iron transformations. I. Iron(II) oxidation and iron(III) colloid formation  

Microsoft Academic Search

Flow injection analysis was used to study the effect of a fulvic acid on the kinetics of iron(II) oxidation and iron colloid formation under conditions approximating fresh natural waters. While iron(II) oxidation in high-carbonate inorganic solutions is predicted well by a recently proposed homogeneous model, it overestimates the oxidation rate in low-carbonate solutions, possibly due to the formation of an

Michael J. Pullin; Stephen E. Cabaniss

2003-01-01

377

Transforming American Education  

ERIC Educational Resources Information Center

|In this article the authors accept as a given the National Education Technology Plan's vision of a transformed education system powered by technology such that learners receive personalized and engaging learning experiences, and where assessment, teaching, infrastructure, and productivity are redefined. The article analyzes this vision of a…

Horn, Michael B.; Mackey, Katherine

2011-01-01

378

Transforming Education with Technology  

ERIC Educational Resources Information Center

|In this EL interview, Karen Cator, the director of the Office of Educational Technology at the U.S. Department of Education, talks about ways to realize the potential of technology to transform education. She discusses what students need: their own digital devices for classroom use, the ability to use the information they access, the skills to…

Scherer, Marge

2011-01-01

379

Transformations: Reflection (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore the reflection transformation both informally and within a coordinate system. Students select and compose shapes and manipulate the axis of symmetry (the mirror) to see the effect on a reflected image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

380

Improved Chirp Transform Correlator.  

National Technical Information Service (NTIS)

This invention relates to a chirp transform correlator in which asynchronous operation is made possible by the use of a pair of paralleled signal processing channels to which the unknown signal to be correlated is applied. The two channels include sweepin...

H. M. Gerard

1983-01-01

381

Transforming Primary Mathematics  

ERIC Educational Resources Information Center

What is good mathematics teaching? What is mathematics teaching good for? Who is mathematics teaching for? These are just some of the questions addressed in "Transforming Primary Mathematics", a highly timely new resource for teachers which accessibly sets out the key theories and latest research in primary maths today. Under-pinned by findings…

Askew, Mike

2011-01-01

382

Bacterial Transformation Lab  

NSDL National Science Digital Library

The "glowing genes" activity on this engaging website shows students the process of bacterial transformation, a specific type of genetic engineering. This online activity supplements a hands-on lab at the Dolan DNA Learning Center's Harlem DNA Lab, in which plasmids, or tiny loops of DNA that contain genes, are inserted into a harmless strain of E.coli.

Dolan DNA Learning Center * (Dolan DNA Learning Center;)

2010-05-27

383

Leading System Transformation  

ERIC Educational Resources Information Center

|This article outlines progress made towards education transformation in Wales. It explores the way in which tri-level reform is guiding system level change in Wales and looks at the implementation of the School Effectiveness Framework, which is at the heart of the reform process. It describes the way in which professional learning communities are…

Harris, Alma

2010-01-01

384

Teaching, Caring, and Transformation  

ERIC Educational Resources Information Center

|Educator Bell Hooks acknowledged the fundamental truth that teaching, caring, and transformation are closely linked, that is, that true teaching must be accompanied by a deep level of care in order for learning to take place. No matter how young or old, no matter the subject matter, and no matter where teaching and learning take place--a…

Nieto, Sonia

2012-01-01

385

Microbial Transformation of Dehydroepiandrosterone  

Microsoft Academic Search

Transformation of dehydroepiandrosterone (DHEA) ( 1 ) was carried out by a plant pathogen Rhizopus stolonifer , which resulted in the production of seven metabolites. These metabolites were identified as 3 g ,17 g -dihydroxyandrost-5-ene ( 2 ), 3 g ,17 g -dihydroxyandrost-4-ene ( 3 ), 17 g -hydroxyandrost-4-ene-3-one ( 4 ), 3 g ,11 g -dihydroxyandrost-4-ene-17-one ( 5 ),

M. Iqbal Choudhary; S. Adnan Ali Shah; S. Ghulam Musharraf; Farzana Shaheen

2003-01-01

386

Fourier Transform I  

NSDL National Science Digital Library

Created by Lang Moore for the Connected Curriculum Project, the purpose of this module is to study the Fourier transform and use it to describe solutions of the heat equation on an infinite rod. This is one of a much larger set of learning modules hosted by Duke University.

Moore, Lang

2010-07-02

387

Transforming Primary Mathematics  

ERIC Educational Resources Information Center

|What is good mathematics teaching? What is mathematics teaching good for? Who is mathematics teaching for? These are just some of the questions addressed in "Transforming Primary Mathematics", a highly timely new resource for teachers which accessibly sets out the key theories and latest research in primary maths today. Under-pinned by findings…

Askew, Mike

2011-01-01

388

Transforming Design Education  

Microsoft Academic Search

The transformation that has been taking place within higher education from new digital technologies and information systems is fundamentally changing the way students will be educated in the future. In Thomas Friedman's book The World is Flat, the author refers to a new global connectivity where everyone has access to the same vast network of information and ideas. The opportunity

Eirik Heintz

2010-01-01

389

Is Distance Learning Transformational?  

ERIC Educational Resources Information Center

|Is distance learning transformational? The author heard this question posed to a panel of faculty members during Distance Education Week activities. After reflecting upon her own students' reaction to her syllabus, her answer to the question changed from an initial, enthusiastic "yes" to a reflective "maybe," given the most favorable…

Hoskins, Barbara J.

2013-01-01

390

Transformations: Rotation (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore the rotation transformation both informally and within a coordinate system. Students select and compose shapes and manipulate the center and angle of rotation to see the effect on a rotated image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

391

Dispersive Fourier transform spectroscopy  

Microsoft Academic Search

Dispersive Fourier transform spectroscopy (DFTS) is a technique for determining the optical constants of solids, liquids and gases from direct measurements of both the amplitude and phase of either their reyection or transmission coeficients. Measurements are usually made at normal incidence with the specimen in one arm of a Michelson interferometer. The technique has been widely used for measurements in

T. J. Parker

1990-01-01

392

Microbial transformation of tetralin  

Microsoft Academic Search

Biocatalytic oxidation of cyclic hydrocarbons has many potential applications in the production of fine chemicals. Especially regioselective hydroxylation of aromatics and the stereospecific formation of secondary alcohols is of interest for the pharmaceutical and flavoring industries. Hydroxylating enzymes are active under mild reaction conditions allowing the controlled transformation of less stable substrates and formation of easily oxidizable products (e.g., catechols).

J. Sikkema

1993-01-01

393

Transforming Education with Technology  

ERIC Educational Resources Information Center

In this EL interview, Karen Cator, the director of the Office of Educational Technology at the U.S. Department of Education, talks about ways to realize the potential of technology to transform education. She discusses what students need: their own digital devices for classroom use, the ability to use the information they access, the skills to…

Scherer, Marge

2011-01-01

394

Transforming Nursery Education.  

ERIC Educational Resources Information Center

|Reviews "Transforming Nursery Education" by Peter Moss and Helen Penn. Maintains that the book clarifies issues and options in child care policy in Great Britain, is highly applicable to the situation in Canada, articulates the importance of values as central to developing early childhood policy and programs, highlights the importance of learning…

Friendly, Martha

1998-01-01

395

Transformative Mixed Methods Research  

ERIC Educational Resources Information Center

|Paradigms serve as metaphysical frameworks that guide researchers in the identification and clarification of their beliefs with regard to ethics, reality, knowledge, and methodology. The transformative paradigm is explained and illustrated as a framework for researchers who place a priority on social justice and the furtherance of human rights.…

Mertens, Donna M.

2010-01-01

396

Rainbow Fourier transform  

NASA Astrophysics Data System (ADS)

We present a novel technique for remote sensing of cloud droplet size distributions. Polarized reflectances in the scattering angle range between 135° and 165° exhibit a sharply defined rainbow structure, the shape of which is determined mostly by single scattering properties of cloud particles, and therefore, can be modeled using the Mie theory. Fitting the observed rainbow with such a model (computed for a parameterized family of particle size distributions) has been used for cloud droplet size retrievals. We discovered that the relationship between the rainbow structures and the corresponding particle size distributions is deeper than it had been commonly understood. In fact, the Mie theory-derived polarized reflectance as a function of reduced scattering angle (in the rainbow angular range) and the (monodisperse) particle radius appears to be a proxy to a kernel of an integral transform (similar to the sine Fourier transform on the positive semi-axis). This approach, called the rainbow Fourier transform (RFT), allows us to accurately retrieve the shape of the droplet size distribution by the application of the corresponding inverse transform to the observed polarized rainbow. While the basis functions of the proxy-transform are not exactly orthogonal in the finite angular range, this procedure needs to be complemented by a simple regression technique, which removes the retrieval artifacts. This non-parametric approach does not require any a priori knowledge of the droplet size distribution functional shape and is computationally fast (no look-up tables, no fitting, computations are the same as for the forward modeling).

Alexandrov, Mikhail D.; Cairns, Brian; Mishchenko, Michael I.

2012-12-01

397

Nature and transformation of dissolved organic matter in treatment wetlands.  

PubMed

This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur. As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated. Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns. Concentrations of specific wastewater-derived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading. PMID:11775156

Barber, L B; Leenheer, J A; Noyes, T I; Stiles, E A

2001-12-15

398

Nature and transformation of dissolved organic matter in treatment wetlands  

USGS Publications Warehouse

This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur. As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated. Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns. Concentrations of specific wastewaterderived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading.

Barber, L. B.; Leenheer, J. A.; Noyes, T. I.; Stiles, E. A.

2001-01-01

399

OVOC Emissions and Atmospheric Transformations.  

NASA Astrophysics Data System (ADS)

We quantified the main emissions from a few vegetation samples and many biomass fires using ground-based, open-path FTIR and airborne, closed-cell FTIR. The two instruments have been rigorously compared to each other and to PTR-MS and canister sampling. OVOC are major emissions from plants. OVOC account for about 70 percent of NMOC from savanna fires (the largest type of biomass burning) and 70-80 percent of NMOC from production and use of domestic biofuels (the second largest type of biomass burning). A table of average biofuel emissions is presented. Data from laboratory and free-burning fires, obtained from Alaska to South Africa, is used to develop equations that predict OVOC emissions from a wide variety of global fires. The impact of OVOC on smoke plume chemistry and the post-emission transformations of OVOC were investigated with two models. Addition of HCHO alone to the simple chemistry used in some global models dramatically reduces NOx lifetime and speeds up O3 formation rates in plumes. A detailed model verifies these effects and shows that OVOC profoundly affect formation of HOx, peroxide, and nitrogen reservoir species. The modeled photochemical transformations of OVOC are diverse, but some key pathways are unknown. We observed rapid production of both O3 and additional OVOC and OH of 1.7E7 in smoke plumes in Alaska and Africa; all reasonably consistent with model predictions. In addition, we found that cloud processing caused large post-emission changes in smoke trace gases including removal of nearly all methanol, a decrease in acetic acid, and a large increase in HCHO. These observations suggest that OVOC could react in cloud droplets and lead to production of modified aerosol. In addition, transport of OVOC by deep convection may be associated with large effects not explained by solubility alone.

Yokelson, R. J.; Christian, T. J.; Bertschi, I. T.; Ward, D. E.; Field, R. J.; Hobbs, P. V.; Goode, J.; Mason, S.; Susott, R.; Babbitt, R.; Hao, W. M.

2002-12-01

400

Martensitic transformation fcc(?)?hcp(?)  

Microsoft Academic Search

Criteria of the thermoelastic martensitic transformation are suggested, on the basis of which the martensitic transformation\\u000a fcc(?)?hcp(?) in Fe?Mn?Si based alloys is classified as a semi-thermoelastic transformation. In contrast with the martensitic\\u000a transformation fcc(?)?bct(bcc)?? in iron-based alloys, the thermoelastic transformation in Cu-based alloys and the t?m transformation\\u000a in ceramics containing ZrO2, in ??? of Fe?Mn?Si, the strengthening and grain size

Zuyao Xu; T. Y. HSU

1997-01-01

401

Altered iron homeostasis involvement in arsenite-mediated cell transformation  

PubMed Central

Chronic exposure to low doses of arsenite causes transformation of human osteogenic sarcoma (HOS) cells. Although oxidative stress is considered important in arsenite-induced cell transformation, the molecular and cellular mechanisms by which arsenite transforms human cells are still unknown. In the present study, we investigated whether altered iron homeostasis, known to affect cellular oxidative stress, can contribute to the arsenite-mediated cell transformation. Using arsenite-induced HOS cell transformation as a model, it was found that total iron levels are significantly higher in transformed HOS cells in comparison to parental control HOS cells. Under normal iron metabolism conditions, iron homeostasis is tightly controlled by inverse regulation of ferritin and transferrin receptor (TfR) through iron regulatory proteins (IRP). Increased iron levels in arsenite transformed cells should theoretically lead to higher ferritin and lower TfR in these cells than in controls. However, the results showed that both ferritin and TfR are decreased, apparently through two different mechanisms. A lower ferritin level in cytoplasm was due to the decreased mRNA in the arsenite-transformed HOS cells, while the decline in TfR was due to a lowered IRP-binding activity. By challenging cells with iron, it was further established that arsenite-transformed HOS cells are less responsive to iron treatment than control HOS cells, which allows accumulation of iron in the transformed cells, as exemplified by significantly lower ferritin induction. On the other hand, caffeic acid phenethyl ester (CAPE), an antioxidant previously shown to suppress As-mediated cell transformation, prevents As-mediated ferritin depletion. In conclusion, our results suggest that altered iron homeostasis contributes to arsenite-induced oxidative stress and, thus, may be involved in arsenite-mediated cell transformation.

Wu, Jing; Eckard, Jonathan; Chen, Haobin; Costa, Max; Frenkel, Krystyna; Huang, Xi

2010-01-01

402

Trichloroethylene transformation by natural mineral pyrite: the deciding role of oxygen.  

PubMed

The transformation of trichloroethylene (TCE) in natural mineral iron disulfide (pyrite) aqueous suspension under different oxygen conditions was investigated in laboratory batch experiments. TCE transformation was pursued by monitoring its disappearance and products released with time. The effect of oxygen was studied by varying the initial dissolved oxygen concentration (DO(i)) inside each reactor. Transformation rates depended strongly on DO(i) in the system. In anaerobic pyrite suspension, TCE did not transform as it did under aerobic conditions. The transformation rate increased with an increase in DO(i). The TCE transformation kinetics was fitted to a pseudo-first-order reaction with a rate constant k (h(-1)) varying from 0.004 to 0.013 for closed systems with DO(i) varying from 0.017 to 0.268 mmol/L under the experimental conditions. In the aerobic systems, TCE transformed to several organic acids including dichloroacetic acid, glyoxylic acid, oxalic acid, formic acid, and finally to CO2 and chloride ion. Dichloroacetic acid was the only chlorinated intermediate found. Both TCE and the pyrite surface were oxidized in the presence of O2. Oxygen consumption profiles showed O2 was the common oxidant in both TCE and pyrite oxidation reactions. Ferric ion cannot be used as an alternative oxidant to oxygen for TCE transformation. PMID:18939588

Pham, Hoa T; Kitsuneduka, Masashi; Hara, Junko; Suto, Koichi; Inoue, Chihiro

2008-10-01

403

GENERALIZED CAUCHY-STIELTJES TRANSFORMS AND MARKOV TRANSFORMS  

Microsoft Academic Search

We express the generalized Cauchy-Stieltjes transforms of some particular Beta distributions depending on a positive parameter as -powered Cauchy-Stieltjes transforms of some probability measures. The Cauchy-Stieltjes transforms of the latter measures are shown to be the geometric mean of the Cauchy-Stieltjes transform of the Wigner law together with another one. More- over, they are absolutely continuous and we derive their

Nizar Demni

404

Effect of the amino chain length and the transformation into citric acid salts of aryl-diphenyl-butenes and ferrocenyl-diphenyl-butenes bearing two dimethylaminoalkyl chains on their antimicrobial activities.  

PubMed

In a previous work we have demonstrated the antimicrobial activity of ferrocenyl or phenyl derivatives of diphenyl butene series. This finding has opened a new area of applications of organometallic compounds. In order to improve these activities, we have synthesized new organic and organometallic diaryl butene compounds with different lengths of their amino chains. These new compounds, and also their ammonium salts, were tested against man pathogenic microorganisms Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442), Staphylococcus aureus (ATCC 6538) and Enterococcus hirae (ATCC 10541). It emerged from the tests that the Gram+ bacteria are more sensitive to the compounds than Gram-, and the compounds with 3 carbon amino chains have a better antimicrobial activity than the one having a chain of 2 or 4 carbons. The transformation of compounds to citrate salts was accompanied by a significant regression of antibacterial activity against Pseudomonas aeruginosa, for both organic and ferrocenic molecules. This resistance problem has been solved using hydrochlorides salts rather than citrates one. PMID:24133651

Jellali, Karim; Pigeon, Pascal; Trigui, Fatma; Top, Siden; Aifa, Sami; Jaouen, Gérard; El Arbi, Mehdi

2013-10-04

405

C-Transformers: a framework to write C program transformations  

Microsoft Academic Search

Program transformation techniques have reached a maturity level that allows processing high-level language sources in new ways. Not only do they revolutionize the implementation of compilers and interpreters, but with modularity as a design philosophy, they also permit the seamless extension of the syntax and semantics of existing programming languages. The C-Transformers project provides a transformation environment for C, a

Alexandre Borghi; Valentin David; Akim Demaille

2006-01-01

406

Transposition of three amino acids transforms the human metabotropic glutamate receptor (mGluR)-3-positive allosteric modulation site to mGluR2, and additional characterization of the mGluR2-positive allosteric modulation site.  

PubMed

Glutamate is a major neurotransmitter in the central nervous system, and abnormal glutamate neurotransmission has been implicated in many neurological disorders, including schizophrenia, Alzheimer's disease, Parkinson's disease, addiction, anxiety, depression, epilepsy, and pain. Metabotropic glutamate receptors (mGluRs) activate intracellular signaling cascades in a G protein-dependent manner, which offer the opportunity for developing drugs that regulate glutamate neurotransmission in a functionally selective manner. In the present study, we further characterize the human mGluR2 (hmGluR2) potentiator binding site by showing that the substitution of the three amino acids found to be required for hmGluR2 potentiation, specifically Ser(688), Gly(689), and Asn(735), with the homologous hmGluR3 amino acids, inactivates the positive allosteric modulator activity of several structurally unique mGluR2 potentiators. Based on the characterization of the hmGluR2 potentiator binding site, we developed a novel scintillation proximity assay that was able to discriminate between compounds that were hmGluR2-specific potentiators, and those that were active on both hmGluR2 and hmGluR3. In addition, we substituted Ser(688), Gly(689), and Asn(735) into hmGluR3 and created an active hmGluR2 allosteric modulation site on the hmGluR3 receptor. PMID:18430863

Rowe, Blake A; Schaffhauser, Hervé; Morales, Sylvia; Lubbers, Laura S; Bonnefous, Celine; Kamenecka, Theodore M; McQuiston, Jeffrey; Daggett, Lorrie P

2008-04-22

407

Mineral oxide transformation of antimicrobial contaminants  

NASA Astrophysics Data System (ADS)

The quality of our water supply is dependent on the organic-mineral interface. Organics contain reactive groups that dissolve minerals, and release surface associated contaminants into aquifers and reservoirs. Conversely, minerals may transform organic pollutants, including antimicrobial drugs that are potentially deleterious to aquatic ecosystems or human health. Under aqueous conditions typical of soils and natural waters, the antibiotic agent sulfamethoxazole (SMX) is transformed in the presence of pyrolusite, presumably on the MnO2 surface. At least 50 percent loss of SMX was observed after 269 h, in both acidic and basic solutions (pH 3-9). Nearly 100 percent loss is recorded at pH 3 and 66 percent loss was recorded at circumneutral pH. Initial mass spectrometry of the reaction products suggests an oxidative pathway where hydroxylation and oxidation occurs at the aniline moiety and isoxazolamine ring of SMX. Concomitant increases in aqueous manganese concentrations suggest reductive transformation of the mineral surface. Ongoing electric force spectroscopy and force microscopy experiments probe potential mineral surface alteration associated with the SMX-MnO2 reaction. Coupling bulk aqueous observations and mass spectrometry with molecular-scale force microscopy should further elucidate sulfonamide reactivity as influenced by mineral surface chemistry and topography. Moreover, the observed transformation suggests manganese oxides likely play an important role in the fate of SMX in the environment.

Guo, B.; Kendall, T. A.

2008-12-01

408

Perinucleolar compartment and transformation.  

PubMed

The perinucleolar compartment (PNC) is a sub-nuclear structure that preferentially localizes to the nucleolar periphery. The PNC is found predominantly in transformed cells both in vitro and in vivo. PNC prevalence (the percentage of cells containing at least one PNC) positively correlates with the progression of breast cancer and patient survival. PNCs are highly enriched with newly synthesized RNA polymerase III transcripts and RNA-binding proteins. The structural integrity of the PNC is dependent upon the transcription of these RNAs and a critical level of the polypyrimidine tract binding (PTB) protein, as assayed by the localization of other PNC-associated proteins. These observations suggest a model in which the PNC is a dynamic, functional organelle that forms under specific physiological conditions favoring cellular transformation and might be involved in the metabolism of RNA polymerase III transcripts. PMID:15770648

Kopp, K; Huang, S

2005-05-15

409

Center for Academic Transformation  

NSDL National Science Digital Library

The Pew Foundation founded the Center for Academic Transformation "to serve as a source of expertise and support for those in higher education who wish to take advantage of the capabilities of information technology to transform their academic practices." Featuring several initiatives, the Center Website offers concise information on The Pew Learning and Technology Program (including a grant program, a symposium, and a newsletter), The Leadership Forum (which includes workshops and resources for academic leaders), and -- the heart of the site -- Center Resources, a collection of articles, monographs, and Websites. The more than two dozen articles cover (broadly) the theory and implementation of technology into the classroom; monographs cover the implications of virtual learning and academic productivity; and Websites point users to dozens of useful sites.

410

Complexity and Army Transformation  

NASA Astrophysics Data System (ADS)

On 12 Octther 1999, the U.S. Army began a journey down a new path to innovation, when General Eric Shinseki presented his vision of Army Transformation at the 45th annual meeting of the Association of the United States Army. In this speech, General Shinseki described the Army as an organization consisting of heavy forces with excellent staying power but poor strategic responsiveness, light forces with excellent responsiveness but poor staying power, and a logistics system with an excessively large footprint. His proposed solution, a comprehensive change of the Army resulting in full-spectrum dominance and strategic responsiveness, would occur so quickly as to "be unnerving to some." [Shinseki. 1999] While this prediction has turned out in some ways to be true, it is not necessarily the speed of change that is unnerving to many of the people studying Army Transformation.

Calhoun, Mark T.

411

Transformations and Frieze Patterns  

NSDL National Science Digital Library

This geometry unit from Illuminations will help students learning about symmetry and rotation in figures and patterns. Using decorative figures and patterns, students will learn to recognize and classify symmetry. Students should have some basic knowledge of the fundamental transformations (translation, rotation and reflection- horizontal and vertical). The unit includes two lessons, each of which should require 1 class period to complete. The material is intended for grades 9-12.

2010-12-29

412

Optimizing power using transformations  

Microsoft Academic Search

The increasing demand for portable computing has elevated power consumption to be one of the most critical design parameters. A high-level synthesis system, HYPER-LP, is presented for mini- mizing power consumption in application specific datapath intensive CMOS circuits using a variety of architectural and computational transformations. The synthesis envir onment consists of high-level esti- mation of power consumption, a library

Anantha P. Chandrakasan; Miodrag Potkonjak; Renu Mehra; Jan M. Rabaey; Robert W. Brodersen

1995-01-01

413

(Hadamard transform imaging)  

SciTech Connect

This report describes the design of, and image reconstruction capacity of a Hadamard Raman Microscopic imager. Microscopy of benzoic acid and graphite electrodes, as well as electrophoretic blotting, are described. (CBS)

Not Available

1990-01-01

414

Cloning a Plant Amino Acid Transporter by Functional Complementation of a Yeast Amino Acid Transport Mutant  

Microsoft Academic Search

Amino acids are transported across the plasma membrane of plant cells by proton-amino acid symports. We report here the successful cloning of a neutral amino acid carrier by functional complementation. A histidine transport deletion mutant of Saccharomyces cerevisiae was transformed with an Arabidopsis thaliana cDNA library constructed in a yeast expression vector. Forty transformants, out of 10^5, allowed growth on

Li-Chu Hsu; Tzyy-Jen Chiou; Lishan Chen; Daniel R. Bush

1993-01-01

415

Spectrum Transformation for Divergent Iterations.  

National Technical Information Service (NTIS)

Certain spectrum transformation techniques are described that can be used to transform a diverging iteration into a converging one. Two techniques are considered called spectrum scaling and spectrum enveloping and how to obtain the optimum values of the t...

M. M. Gupta

1991-01-01

416

Transformational Leadership, Integrity, and Power  

ERIC Educational Resources Information Center

|Transformational leadership enjoys widespread appeal among student affairs professionals. National Association of Student Personnel Administrators (NASPA) and American College Personnel Association (ACPA) conferences frequently feature speakers who promote transformational leadership's two primary tenets: (1) change is the central purpose of…

Harrison, Laura M.

2011-01-01

417

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

418

Transformation method and wave control  

NASA Astrophysics Data System (ADS)

Transformation method provides an efficient way to control wave propagation by materials. The transformed relations for field and material during a transformation are essential to fulfill this method. We propose a systematic method to derive the transformed relations for a general physic process, the constraint conditions are obtained by considering geometrical and physical constraint during a mapping. The proposed method is applied to Navier's equation for elastodynamics, Helmholtz's equation for acoustic wave and Maxwell's equation for electromagnetic wave, the corresponding transformed relations are derived, which can be used in the framework of transformation method for wave control. We show that contrary to electromagnetic wave, the transformed relations are not uniquely determined for elastic wave and acoustic wave, so we have a freedom to choose them differently. Using the obtained transformed relations, we also provide some examples for device design, a concentrator for elastic wave, devices for illusion acoustic and illusion optics are conceived and validated by numerical simulations.

Chang, Zheng; Hu, Jin; Hu, Geng-Kai

2010-12-01

419

Recent Advances in Transformation Optics.  

National Technical Information Service (NTIS)

Within the past a few years, transformation optics has emerged as a new research area, since it provides a general methodology and design tool for manipulating electromagnetic waves in a prescribed manner. Using transformation optics, researchers have dem...

X. Zhang Y. Liu

2012-01-01

420

RECENT ADVANCES IN BARLEY TRANSFORMATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Barley, an important member of the cereals, has been successfully transformed through various methods such as particle bombardment, Agrobacterium-tumefaciens, DNA uptake, and electroporation. Initially, the transformation in barley concentrated on developing protocols using marker genes such as gus,...

421

Nitrogen Transformations in Wetland Soils.  

National Technical Information Service (NTIS)

Nitrogen transformation pathways often become complex in soils that are periodically subjected to submergence. Both biochemical and chemical mechanisms can be implicated in these transformations. Nitrate accumulation in the environment has caused much con...

R. E. Hoeppel

1974-01-01

422

Elliptic Systems and Numerical Transformations.  

National Technical Information Service (NTIS)

Properties of a transformation method, which was developed for solving fluid dynamic problems on general two dimensional regions, are discussed. These include construction error of the transformation and applications to mesh generation. An error and stabi...

C. W. Mastin J. F. Thompson

1976-01-01

423

Adaptive wavelet transforms via lifting  

Microsoft Academic Search

This paper develops two new adaptive wavelet transforms based on the lifting scheme. The lifting construction exploits a spatial-domain, prediction-error interpretation of the wavelet transform and provides a powerful framework for designing customized transforms. We use the lifting construction to adaptively tune a wavelet transform to a desired signal by optimizing data-based prediction error criteria. The performances of the new

Roger L. Claypoole; Richard G. Baraniuk; Robert D. Nowak

1998-01-01

424

Sonolysis of Short-Chain Organic Dicarboxylic Acid Solutions  

NASA Astrophysics Data System (ADS)

Sonolyses of C4 (carbon number 4) dicarboxylic acids (succinic acid, maleic acid, and fumaric acid) were performed in aqueous solution. They changed one into the other during sonication, affording carbon-number-conserving transformations. Maleic acid and fumaric acid were produced from saccinic acid by dehydrogenation. Furthermore, malic acid and tartaric acid were obtained by hydroxylation. The sonochemical reaction processes are discussed in terms of the time dependences of products and the addition of radical scavengers. In addition, mutual isomerization of fumaric acid and maleic acid was observed during sonication without the use of mediators.

Naruke, Yukio; Harada, Hisashi

2011-07-01

425

The Conversion of Carboxylic Acids to Ketones: A Repeated Discovery  

ERIC Educational Resources Information Center

|The conversion of carboxylic acids to ketones is a useful chemical transformation with a long history. Several chemists have claimed that they discovered the conversion of carboxylic acids to ketones yet in fact the reaction is actually known for centuries.|

Nicholson, John W.; Wilson, Alan D.

2004-01-01

426

The Conversion of Carboxylic Acids to Ketones: A Repeated Discovery  

ERIC Educational Resources Information Center

The conversion of carboxylic acids to ketones is a useful chemical transformation with a long history. Several chemists have claimed that they discovered the conversion of carboxylic acids to ketones yet in fact the reaction is actually known for centuries.

Nicholson, John W.; Wilson, Alan D.

2004-01-01

427

Indium(III)-Catalyzed Reductive Bromination and Iodination of Carboxylic Acids to Alkyl Bromides and Iodides: Scope, Mechanism, and One-Pot Transformation to Alkyl Halides and Amine Derivatives.  

PubMed

Highly effective indium(III)-catalyzed reductive bromination or iodination of a variety of carboxylic acids with 1,1,3,3-tetramethyldisiloxane (TMDS) and a source of bromine or iodine is described. This functional group interconversion has high tolerance for several functional groups, such as halogens, a hydroxy group, a nitro group, an olefin part, and a sulfide moiety. This indium catalytic system is also applicable to the reductive iodination of aldehyded, acyl chlorides, and esters. Furthermore, this reducing system can be applied to the one-pot synthesis of alkyl halides and amine derivatives via the addition of nucleophiles. Insight into the reaction mechanism was gained via the time course of (1)H and (13)C NMR monitoring experiments and the corresponding stepwise reactions. PMID:24087920

Moriya, Toshimitsu; Yoneda, Shinichiro; Kawana, Keita; Ikeda, Reiko; Konakahara, Takeo; Sakai, Norio

2013-10-23

428

Chloroplast transformation for engineering of photosynthesis.  

PubMed

Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation. PMID:23162121

Hanson, Maureen R; Gray, Benjamin N; Ahner, Beth A

2012-11-16

429

[Transformations of erythrocytes shape and its regulation].  

PubMed

Erythrocytes can occur in many different shapes. Most of them are pathological and can be involved in diseases such a hemolytic anemia's and sickle cell anemia. Only three kinds of red blood cells are no pathological. Echinocytes, stomatocytes and discocytes can occure in blood stream of healthy organism. The echinocyte-dyscocyte-stomatocyte transformation protects red blood cells from lysis caused by echinocytogenic agents (hypertonic saline, basic pH, vanadate, anionic amphiphiles, ATP depletion etc.) or stomatocytogenic agents (hypotonic saline, acidic pH, cationic amphiphiles etc.). Mechanisms of these transformations can be classified in three group: redistribution of bilayer's lipid, modification Donnan's equilibrium and interaction of band 3 protein with different type of external factors. PMID:20201356

Stasiuk, Maria; Kijanka, Grzegorz; Kozubek, Arkadiusz

2009-01-01

430

Schematic transformation diagrams for steel  

Microsoft Academic Search

This paper examines the diffusional transformations of austenite and concludes that separate C-curves are required for pearlite, upper bainite, lower bainite and isothermal martensite. A schematic isothermal transformation diagram incorporating the four curves is presented for a plain carbon eutectoid steel and used to develop a schematic continuous cooling transformation diagram. These diagrams are shown to be more compatible with

Noel F. Kennon

1978-01-01

431

The discrete periodic Radon transform  

Microsoft Academic Search

In this correspondence, a discrete periodic Radon transform and its inversion are developed. The new discrete periodic Radon transform possesses many properties similar to the continuous Radon transform such as the Fourier slice theorem and the convolution property, etc. With the convolution property, a 2-D circular convolution can be decomposed into 1-D circular convolutions, hence improving the computational efficiency. Based

Taichiu Hsung; Daniel P. K. Lun; Wan-Chi Siu

1996-01-01

432

Enhancing Understanding of Transformation Matrices  

ERIC Educational Resources Information Center

|With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

Dick, Jonathan; Childrey, Maria

2012-01-01

433

Canonical Transformations of Kepler Trajectories  

ERIC Educational Resources Information Center

|In this paper, canonical transformations generated by constants of motion in the case of the Kepler problem are discussed. It is shown that canonical transformations generated by angular momentum are rotations of the trajectory. Particular attention is paid to canonical transformations generated by the Runge-Lenz vector. It is shown that these…

Mostowski, Jan

2010-01-01

434

Model transformations and tool integration  

Microsoft Academic Search

Model transformations are increasingly recog- nised as being of significant importance to many areas of software development and integration. Recent attention on model transformations has particularly focused on the OMG's Queries \\/ Views \\/ Transformations (QVT) Request for Proposals (RFP). In this paper I motivate the need for dedicated approaches to model transforma- tions, particularly for the data involved in

Laurence Tratt

2005-01-01

435

Transformational leadership and team performance  

Microsoft Academic Search

Despite transformational leadership enjoying success and attention as an exceptional leadership theory, few scholars have investigated a specific link between transformational leadership theory and team performance. As such, we discuss how transformational leadership theory can provide a framework in which to investigate a leader's impact on team performance. We posit that idealized influence\\/inspirational motivation, intellectual stimulation and individualized consideration could

Shelley D. Dionne; Francis J. Yammarino; Leanne E. Atwater; William D. Spangler

2004-01-01

436

Enhancing Understanding of Transformation Matrices  

ERIC Educational Resources Information Center

With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

Dick, Jonathan; Childrey, Maria

2012-01-01

437

Canonical Transformations of Kepler Trajectories  

ERIC Educational Resources Information Center

In this paper, canonical transformations generated by constants of motion in the case of the Kepler problem are discussed. It is shown that canonical transformations generated by angular momentum are rotations of the trajectory. Particular attention is paid to canonical transformations generated by the Runge-Lenz vector. It is shown that these…

Mostowski, Jan

2010-01-01

438

Inversion of the circular averages transform using the Funk transform  

NASA Astrophysics Data System (ADS)

The integral of a function defined on the half-plane along the semi-circles centered on the boundary of the half-plane is known as the circular averages transform. Circular averages transform arises in many tomographic image reconstruction problems. In particular, in synthetic aperture radar (SAR) when the transmitting and receiving antennas are colocated, the received signal is modeled as the integral of the ground reflectivity function of the illuminated scene over the intersection of spheres centered at the antenna location and the surface topography. When the surface topography is flat the received signal becomes the circular averages transform of the ground reflectivity function. Thus, SAR image formation requires inversion of the circular averages transform. Apart from SAR, circular averages transform also arises in thermo-acoustic tomography and sonar inverse problems. In this paper, we present a new inversion method for the circular averages transform using the Funk transform. For a function defined on the unit sphere, its Funk transform is given by the integrals of the function along the great circles. We used hyperbolic geometry to establish a diffeomorphism between the circular averages transform, hyperbolic x-ray and Funk transforms. The method is exact and numerically efficient when fast Fourier transforms over the sphere are used. We present numerical simulations to demonstrate the performance of the inversion method. Dedicated to Dennis Healy, a friend of Applied Mathematics and Engineering.

Evren Yarman, Can; Yaz?c?, Birsen

2011-06-01

439

A General Spectral Transformation Simultaneously Including a Fourier Transformation and a Laplace Transformation.  

National Technical Information Service (NTIS)

A general spectral transformation is proposed and described. Its spectrum can be interpreted as a Fourier spectrum or a Laplace spectrum. The laws and functions of the method are discussed in comparison with the known transformations, and a sample applica...

H. Marko

1978-01-01

440

Identification of another member of the transforming growth factor type beta gene family.  

PubMed Central

We report here the complete amino acid sequence of another member of the type beta transforming growth factor gene family, deduced from the nucleotide sequence of three overlapping cDNA clones. The C-terminal 112 amino acids share approximately 80% sequence identity with type beta 1 and beta 2 transforming growth factors, with many of the remaining differences being conservative substitutions. By analogy to type beta 1 and type beta 2 transforming growth factors, we predict the protein to be synthesized as a 412 amino acid precursor that undergoes proteolytic cleavage to produce the mature polypeptide. Images

ten Dijke, P; Hansen, P; Iwata, K K; Pieler, C; Foulkes, J G

1988-01-01

441

Computer simulation of martensitic transformations  

SciTech Connect

The characteristics of martensitic transformations in solids are largely determined by the elastic strain that develops as martensite particles grow and interact. To study the development of microstructure, a finite-element computer simulation model was constructed to mimic the transformation process. The transformation is athermal and simulated at each incremental step by transforming the cell which maximizes the decrease in the free energy. To determine the free energy change, the elastic energy developed during martensite growth is calculated from the theory of linear elasticity for elastically homogeneous media, and updated as the transformation proceeds.

Xu, Ping

1993-11-01

442

Formation of delta 2- and delta 3-cholenoic acids from bile acid 3-sulfates by a human intestinal Fusobacterium strain.  

PubMed Central

We isolated two strains of an unnamed Fusobacterium species from human intestinal microflora, which stereospecifically transformed bile acid 3-sulfates into C-3-unsubstituted, ring A-unsaturated bile acids. Both 3 alpha- and 3 beta-sulfates of 5 beta-bile acids were metabolized to delta 3-5 beta-cholenoic acids; 3 beta-sulfates of 5 alpha-bile acids were converted into a mixture of delta 2-5 alpha-bile acids and 3 alpha-hydroxy-5 alpha-bile acids, whereas 3 alpha-sulfates of 5 alpha-bile acids were left intact. Unsulfated bile acids were not transformed into unsaturated derivatives. These strains differ from previously isolated intestinal bacteria, which desulfated bile acid sulfates without further transformation.

Robben, J; Janssen, G; Merckx, R; Eyssen, H

1989-01-01

443

A Fast Hermite Transform?  

PubMed Central

We present algorithms for fast and stable approximation of the Hermite transform of a compactly supported function on the real line, attainable via an application of a fast algebraic algorithm for computing sums associated with a three-term relation. Trade-offs between approximation in bandlimit (in the Hermite sense) and size of the support region are addressed. Numerical experiments are presented that show the feasibility and utility of our approach. Generalizations to any family of orthogonal polynomials are outlined. Applications to various problems in tomographic reconstruction, including the determination of protein structure, are discussed.

Leibon, Gregory; Rockmore, Daniel N.; Park, Wooram; Taintor, Robert; Chirikjian, Gregory S.

2008-01-01

444

Transforming cultural chaos.  

PubMed

Kotter believes that generating short-term wins is a critical component of the change and transformation process. Our short-term win-wins have allowed us to further collaborate, which consequently has given us more wins. These wins have been communicated. The communication has conveyed a sense of optimism and hope, and has empowered people to view change as a positive challenge. The challenge has become one in which all want to participate. Finally, we are at a point where the end of one way of life is truly the beginning of a new and better way of life. T.S. Eliot was right! PMID:10373978

Schloeder, D

1999-03-01

445

Microbial transformation of kepone.  

PubMed Central

Pseudomonas aeruginosa strain KO3 and a mixed aerobic enrichment culture, isolated from sewage sludge lagoon water, were found to aerobically transform the chlorinated insecticide Kepone, yielding monohydro-Kepone. Identification of the product was confirmed by gas chromatography and electron impact mass spectrometry. The mixed culture and P. aeruginosa strain KO3 produced about 4 and 16%, respectively, dihydro-Kepone, determined by cochromatography using authentic standards. Reduced amounts of monohydro-Kepone, compared with the mixed and pure cultures, were produced by James River sediment microorganisms. Kepone was not utilized as a sole carbon or energy source by any of the bacteria or mixed cultures examined in this study.

Orndorff, S A; Colwell, R R

1980-01-01

446

[Metabolic transformation of schizandrin].  

PubMed

The metabolic transformation of schizandrin, isolated from the kernel of Schizandra chinensis Bill, was studied in vitro with phenobarbital-induced rat liver microsomal fractio containing the NADPH-generating system. The major metabolites were isolated by preparative HPLC and identified as 7,8-dihydroxy-schizandrin, 7,8-dihydroxy-2-demethyl schizandrin and 7,8-dihydroxy-3-demethyl schizandrin by UV, NMR, MS spectral analysis. The 7,8-dihydroxy-schizandrin was confirmed further by comparison with spectral and chromatographic behavior of the authentic compound. The metabolic biotransformation of schizandrin in vivo was also determined. PMID:1529716

Cui, Y Y; Wang, M Z

1992-01-01

447

Bacterial Transformation Lab  

NSDL National Science Digital Library

This PDF, part of the classroom activities site by Biotechnology Education and Training Sequence Investment (BETSI), introduces the concept of recombinant DNA and a process called transformation. Here, instructors will find detailed lab instructions/diagrams that trace out the introduction of a recombinant plasmid into a foreign bacteria resulting in the "change of the bacteria's genetic make-up and traits." With the end result of the lab being a product that "glow[s] bright green," this will be a fun lab for any chemistry or biochemistry classroom. The site even playfully boasts, "[that] you will all be genetics engineers" by the end of this experiment!

2008-12-10

448

Distinctive transforming genes in x-ray-transformed mammalian cells  

SciTech Connect

DNAs from hamster embryo cells and mouse C3H/10T1/2 cells transformed in vitro by x-irradiation into malignant cells transmit the radiation transformation phenotype by producing transformed colonies (transfectants) in two mouse recipient lines, the NIH 3T3 and C3H/101/2 cells, and in a rat cell line, the Rat-2 cells. DNAs from unirradiated cells or irradiated and visibly untransformed cells do not produce transformed colonies. The transfectant grow in agar and form tumors in nude mice. Treatment of the DNAs with restriction endonucleases prior to transfection indicates that the same transforming gene (oncogene) is present in each of the transformed mouse cells and is the same in each of the transformed hamster cells. Southern blot analysis of 3T3 or Rat-2 transfectants carrying oncogenes from radiation-transformed C3H/10T1/2 or hamster cells indicates that the oncogenes responsible for the transformation of 3T3 cells are not the Ki-ras, Ha-ras, N-ras genes, nor are they neu, trk, raf, abl, or fms. The work demonstrates that DNAs from mammalian cells transformed into malignancy by direct exposure in vitro to radiation contain genetic sequences with detectable transforming activity in three recipient cell lines. The results provide evidence that DNA is the target of radiation carcinogenesis induced at a cellular level in vitro. The experiments indicate that malignant radiogenic transformation in vitro of hamster embryo and mouse C3H/10T1/2 cells involves the activation of unique non-ras transforming genes, which heretofore have not been described.

Borek, C.; Ong, A.; Mason, H.

1987-02-01

449

Bound state transformation walls  

NASA Astrophysics Data System (ADS)

In four dimensional N = 2 supergravity theories, BPS bound states near marginal stability are described by configurations of widely separated constituents with nearly parallel central charges. When the vacuum moduli can be dialed adiabatically until the central charges become anti -parallel, a paradox arises. We show that this paradox is always resolved by the existence of "bound state transformation walls" across which the nature of the bound state changes, although the index does not jump. We find that there are two distinct phenomena that can take place on these walls, which we call recombination and conjugation. The latter is associated to the presence of singularities at finite distance in moduli space. Consistency of conjugation and wall-crossing rules near these singularities leads to new constraints on the BPS spectrum. Singular loci supporting massless vector bosons are particularly subtle in this respect. We argue that the spectrum at such loci necessarily contains massless magnetic monopoles, and that bound states around them transform by intricate hybrids of conjugation and recombination.

Andriyash, Evgeny; Denef, Frederik; Jafferis, Daniel L.; Moore, Gregory W.

2012-03-01

450

Energy: Energy Transformations  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Energy SciPack. It provides a conceptual and real-world understanding of how energy is transferred, from object to object and from one form of energy to another. Although the various forms of energy appear different, each can be measured in a closed system. This makes it possible to keep track of how much of one form of energy is converted into another form. Most of what goes on in the universe--from exploding stars and biological growth to the operation of machines and the motion of people--involves some form of energy being transformed into another form. The law of conservation of energy states that whenever the amount of energy in one place (or form) decreases, the amount of energy in other places (or forms) increases by the same amount. Learning Outcomes:� Recognize that there are ways to measure the amount of different kinds of energy that allow us to track how much of one form is changed into another.� Recognize that energy is conserved, meaning it is not "used up" and does not appear out of nowhere.� Give examples of transformation of energy, including recognizing the forms of energy involved.� Construct an argument against an example that claims to be a perpetual motion machine.

National Science Teachers Association (NSTA)

2006-11-01

451

Transformations of emotional experience.  

PubMed

In this paper the author approaches mental pain and the problems in a psychoanalytic treatment of patients with difficulties in the psychic transformation of their emotional experiences. The author is interested in the symbolic failure related to the obstruction of development of phantasies, dreams, dream-thoughts, etc. She differentiates symbolization disturbances related to hypertrophic projective identification from a detention of these primitive communications and emotional isolation. She puts forward the conjecture that one factor in the arrest of this development is the detention of projective identifications and that, when this primitive means of communication is re-established in a container-contained relationship of mutual benefit, this initiates the development of a symbolization process that can replace the pathological 'protection'. Another hypothesis she develops is that of inaccessible caesuras that, associated with the detention of projective identification, obstruct any integrative or interactive movement. This caesura and the detention of projective identifications affect mental functions needed for dealing with mental pain. The personality is left with precarious mental equipment for transforming emotional experiences. How can a psychoanalytical process stimulate the development of creative symbolization, transforming the emotional experiences and leading towards mental growth? The author approaches the clinical problem with the metaphor of the psychic birth of emotional experience. The modulation of mental pain in a container-contained relationship is a central problem for the development of the human mind. For discovering and giving a meaning to emotional experience, the infant depends on reverie, a function necessary in order to develop an evolved consciousness capable of being aware, which is different from the rudimentary consciousness that perceives but does not understand. The development of mature mental equipment is associated with the personality's attitude towards mental pain. The differentiation between psychotic, neurotic or autistic functioning depends on what defences are erected to avoid mental pain. The primary link between infant and mother is where the building of mental equipment takes place, through communicational forms that, to begin with, are not verbal. The author suggests the need for the development of an ideo-grammar (in gestures, paralinguistic forms, etc.) in primary relations, as the precursor forms that will become the matrix for the mental tools for dealing with emotional experiences in a mature way. The paper stresses the significance of the parental containing function for the development of symbolization of prenatal emotional experiences. This containment develops ideograms, transformations of sense impressions into proto-symbols, instruments that attenuate the traumatic experiences of helplessness. The author takes Bion's ideas about extending the notion of dream-work to an alpha function that goes on continually, day and night, transforming raw emotional experiences in a 'dream'. In order to acquire a meaning, facts need to be 'dreamed' in this extended sense. Meaning and truth are the nurture of the mind. Mental growth, the devel